KR101775749B1 - Modifier for rubber composition, manufacturing method thereof and rubber composition comprising the modifier - Google Patents

Abstract

The present invention relates to a modifier for a rubber composition capable of improving the dispersibility in rubber to improve the rubber composition when the rubber composition is mixed with rubber, in particular, improving the abrasion resistance, tensile strength and tear strength and improving wet road surface resistance, And the modifier, wherein the modifier for the rubber composition according to the present invention comprises 50 to 90% by weight of a rubber latex (based on solid content); 5 to 40% by weight of an aromatic vinyl monomer graft-copolymerized with the rubber latex; And 1 to 10% by weight of a polyethylene glycol monomer graft-copolymerized with the rubber latex.

Description

TECHNICAL FIELD [0001] The present invention relates to a modifier for a rubber composition, a method for producing the same, and a rubber composition comprising the modifier,

The present invention relates to a modifier for a rubber composition, a method for producing the same, and a rubber composition comprising the modifier. More particularly, the present invention relates to a modifier for modifying a rubber composition, To a modifier for a rubber composition capable of improving wet strength and tear strength and capable of improving wet non-slip property, a process for producing the same, and a rubber composition comprising the modifier.

In the past, various modifiers have been used for rubber in order to improve the physical properties of rubber. Prior art related to this is US Patent No. US 5395891, US Patent Application No. US 2002/0007011, US 2004/0127603, etc. have.

US Patent No. 5,395,891 discloses a rubber composition comprising a polybutadiene gel and discloses that crosslinked polybutadiene can be used in rubber to improve hysteresis loss and abrasion resistance , US Patent Application Publication No. US 2002/0007011 discloses crosslinked rubber particles and a rubber composition. It is disclosed that a gel content is 80% or more by using butadiene, a styrene monomer, a crosslinking agent, and a functional monomer And that when the crosslinked rubber particles are used in the rubber composition, workability and dimensional stability can be improved. In addition, US Patent Publication No. 2004/0127603 discloses a core-shell polymer particle, wherein an aromatic vinyl monomer is used for a core and a conjugated diene monomer is used for a shell Discloses that core-shell polymer can be used as an additive in rubber.

However, according to the above-mentioned patents, there is a problem in that the modifier for modifying the rubber composition is not compatible with the rubber of the modifier to be mixed with the rubber and is not well dispersed in the rubber.

An object of the present invention is to provide a modifier for a rubber composition which is improved in compatibility with rubber by graft copolymerizing an aromatic vinyl monomer and a polyethylene glycol monomer to a rubber latex.

Another object of the present invention is to provide a rubber composition comprising the modifier.

The rubber composition according to the present invention comprises 50 to 90% by weight of a rubber latex (based on solid content), 5 to 40% by weight of an aromatic vinyl monomer graft-copolymerized with the rubber latex, and a polyethylene glycol-based monomer 1 To 10% by weight of a modifier for a rubber composition, and 100 parts by weight of the rubber.

Also, the modifier for the rubber composition according to the present invention comprises 50 to 90% by weight of rubber latex (based on solid content); 5 to 40% by weight of an aromatic vinyl monomer graft-copolymerized with the rubber latex; And 1 to 10% by weight of a polyethylene glycol monomer graft-copolymerized with the rubber latex.

According to the present invention, in order to improve the compatibility with rubber, it is possible to improve the dispersibility of the modifier in the rubber by providing a modifier obtained by copolymerizing polyethylene glycol monomer in the production of a modifier, in particular graft copolymerization, There is provided a modifier for a rubber composition capable of improving the physical properties of the composition, in particular, the abrasion resistance, the tensile strength and the tear strength, and the wet non-slip property, a method for producing the same, and a rubber composition comprising the modifier It is effective.

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

≪ Preparation of rubber composition >

The rubber composition according to the present invention comprises 50 to 90% by weight of a rubber latex (based on solid content), 5 to 40% by weight of an aromatic vinyl monomer graft-copolymerized with the rubber latex, and a polyethylene glycol-based monomer 1 To 10% by weight of a modifier for a rubber composition, and 100 parts by weight of the rubber.

As the rubber, a butadiene rubber, a styrene-butadiene rubber, an acrylonitrile-butadiene rubber, a natural rubber, or the like can be used.

The rubber composition according to the present invention preferably contains an amount within a range of 2 to 50 parts by weight of the modifier for the rubber composition according to the present invention based on 100 parts by weight of the rubber, It has an effect of improving physical properties, particularly abrasion resistance, tensile strength and tear strength, and improving wet road surface resistance.

In addition, the rubber composition may further optionally contain fillers such as carbon black, silica, etc., crosslinking agents, antioxidants, vulcanization accelerators, etc., which are known in the field of the present invention.

The rubber composition prepared according to the present invention has an effect of improving abrasion resistance, tensile strength and tear strength, and improving wet road surface resistance.

The modifier for the rubber composition according to the present invention comprises 50 to 90% by weight of rubber latex (based on solid content); 5 to 40% by weight of an aromatic vinyl monomer graft-copolymerized with the rubber latex; And 1 to 10% by weight of a polyethylene glycol monomer graft-copolymerized with the rubber latex.

(a) Production of rubber latex

In the present invention, the rubber latex used in the preparation of the modifier is a single layer or a multi-layer structure, and the rubber latex is synthesized using a conjugated diene monomer, an aromatic vinyl monomer and a crosslinking agent. The glass transition temperature and degree of crosslinking of the rubber latex can be controlled by adjusting the kind and content of the conjugated diene monomer, aromatic vinyl monomer and crosslinking agent, etc., and it is also possible to change it according to the type of rubber and the desired properties.

The rubber latex may be a homopolymer of the conjugated diene monomer or a copolymer of the conjugated diene monomer and the aromatic vinyl monomer.

The conjugated diene monomer used in the production of the rubber latex has a function of lowering the glass transition temperature of the modifier. Specifically, one or more kinds selected from the group consisting of butadiene, isoprene, and chloroisoprene can be used.

The rubber latex may be a homopolymer of the conjugated diene-based monomer, which means that all of the rubber latex is composed of the conjugated diene-based monomer.

The rubber latex may be a copolymer of the conjugated diene monomer and the aromatic vinyl monomer. The aromatic vinyl monomer used in the preparation of the copolymer serves to control the glass transition temperature of the rubber latex. Specific examples thereof include styrene, alpha methyl styrene, isopropyl phenyl naphthalene, vinyl naphthalene, C1-C3-alkyl substituted Styrene, and halogen-substituted styrene.

The aromatic vinyl monomer is preferably used in an amount of 0.1 to 45% by weight, more preferably 0.1 to 35% by weight, based on 100% by weight of the rubber latex (based on solid content) The glass transition temperature of the modifier is controlled to be low.

In the production of the rubber latex, a cross-linking agent may be used, and the cross-linking agent used to control the degree of cross-linking of the rubber latex. Specific examples thereof include divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, aryl methacrylate, and 1,3 -Butylene glycol diacrylate, and the like. The crosslinking agent may be used in an amount within a range of 0.1 to 5% by weight based on 100% by weight of a rubber latex (based on solid content), but is preferably used in an amount within a range of 0.1 to 3% by weight.

The method for producing the rubber latex in the present invention is not particularly limited and can be produced by a method well known to those skilled in the art. The particle size and gel content of the rubber latex are not particularly limited.

(b) Preparation of modifier for rubber composition

The modifier for a rubber composition according to the present invention comprises (a) 50 to 90% by weight of the rubber latex (based on solid content) prepared as described above based on 100% by weight of the modifier, 5 to 40% by weight of an aromatic vinyl monomer, And 1 to 10% by weight of the copolymer.

Here, it is preferable to use 50 to 90% by weight of the rubber latex (based on solid content) prepared above, and it is possible to produce the modifier in a powder state while maintaining the wet road surface resistance of the rubber composition within this range .

The aromatic vinyl monomer may be graft-copolymerized with the rubber latex to convert the modifier into a powder state. Specific examples of the aromatic vinyl monomer include styrene, alpha methyl styrene, isopropyl phenyl naphthalene, vinyl naphthalene, C1- And halogen-substituted styrene are preferable.

The aromatic vinyl monomer is preferably used in an amount of 5 to 40% by weight in the preparation of the modifier, and the modifier can be produced in powder form within the range, and the wet surface resistance of the rubber composition containing the modifier Is maintained.

The polyethylene glycol-based monomer may be at least one selected from the group consisting of monomers represented by the following general formula (1) or (2).

Wherein A is a substituent group containing a vinyl group, R is an ethylene group, and m is an integer of 5 to 14.

In the above formula (2), A 'and A "are substituents containing a vinyl group, R' is an ethylene group, and n is an integer of 5 to 14.

The substituent containing a vinyl group in A, A 'and A' above may be a (meth) acrylate group containing a vinyl group.

In the substituent comprising the vinyl group, the (meth) acrylate group may include a substituent group having an acrylate group or a methacrylate group as a basic skeleton.

In the preparation of the modifier, it is preferable to use 1 to 10% by weight of the polyethylene glycol monomer, and the modifier can be produced in a powder state within the range, and the wet surface of the rubber composition containing the modifier It is effective to maintain the resistance.

The reaction medium, the initiator, the emulsifier, the catalyst, the stabilizer, and the like may be used in a conventional manner without particular limitation, as long as they are well known in the art to which the present invention belongs. The description of the embodiments can be referred to these. For example, the emulsifying agent may be selected from various types well known in the art of emulsion polymerization. Preferable examples thereof include fatty acid salts such as potassium salts of fatty acids and potassium oleates, and alkali metal salts of weak acids.

Examples of the polymerization initiator include water-soluble polymerization initiators such as sodium persulfate, potassium persulfate, and peroxy compounds; and water-soluble polymerization initiators such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, azobisisobutylnitrile, tertiary butyl hydroperoxide , Para-methane hydroperoxide or benzoyl peroxide, can be used.

The polymerization conditions of the polymerization of the rubber latex and the graft polymerization of the modifier are not particularly limited.

(C) Preparation of modifier particle powder

The modifier is obtained in the form of a latex by the graft copolymerization, and the latex may be produced as a powdery particle through an agglomeration step. In the flocculating method of the modifier, the type and the flocculating conditions of the flocculant are not particularly limited as long as they are known in the technical field of the present invention without any particular limitation.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[Example]

Example 1

≪ Preparation of rubber latex >

The weight% of the following compounds is based on 100 wt% of the monomer mixture used for the preparation of the rubber latex used as the core of the modifier, and parts by weight are based on 100 parts by weight of the monomer mixture.

To a 120 L high-pressure polymerization vessel equipped with a stirrer, 150 parts by weight of ion-exchanged water, 0.5 parts by weight of potassium chloride as an additive, 1.0 part by weight of potassium oleate, 0.0047 part by weight of ethylenediaminetetra sodium acetate, 0.003 part by weight of ferrous sulfate, 0.02 part by weight of hydroxyethylcellulose and 0.1 part by weight of diisopropylbenzene hydroperoxide were initially charged. 75% by weight of butadiene, 24% by weight of styrene and 1% by weight of divinylbenzene were charged and polymerized at 35 DEG C for 10 hours to obtain a styrene-butadiene rubber latex having a particle size of 1000 ANGSTROM, and its final polymerization conversion rate was 98%.

≪ Preparation of modifier particles >

The weight percentages of the following compounds are based on 100 weight percent of the mixture of the rubber latex and freshly added monomers used for the preparation of the modifier and the parts by weight are based on 100 weight parts of the mixture of the rubber latex and the newly added monomer will be.

80% by weight (based on solid content) of the obtained rubber latex was charged into a closed reactor and then charged with nitrogen. Then, 0.0094 part by weight of ethylenediaminetetra sodium acetate, 0.006 part by weight of ferrous sulfate, and sodium formaldehyde sulfoxylate And 0.1 part by weight of t-butyl hydroperoxide was added to the resulting mixture at 50 ° C for 1 hour After the addition, further polymerization was carried out for 1 hour.

≪ Preparation of modifier particle powder >

The modifier particles on the prepared latex were solidified with hydrochloric acid to separate the polymer and water, followed by dehydration-drying to obtain a modifier particle powder.

≪ Preparation of rubber composition >

And 15 parts by weight of the modifier particle powder prepared by the above method were mixed with 100 parts by weight of a butadiene rubber prepared by mixing a silica filler to prepare a rubber composition and a rubber specimen was prepared therefrom. The results are shown in Table 1 below.

Example 2

Instead of 80% by weight of 70% by weight of rubber latex (based on solids) was used in the preparation of the modifier, styrene was used in an amount of 24% by weight instead of 16% by weight, and polyethylene glycol methacrylate was used instead of 4% Was used in an amount of 6% by weight.

Comparative Example 1

The procedure of Example 1 was repeated except that no modifier was added to 100 parts by weight of butadiene rubber.

Comparative Example 2

Butadiene rubber was used in an amount of 55 parts by weight instead of 15 parts by weight of modifier in 100 parts by weight of the butadiene rubber.

Comparative Example 3

In the preparation of the modifier, the rubber latex (in terms of solid content) was used in an amount of 92 wt% instead of 80 wt%, styrene was used in an amount of 6.4 wt% instead of 16 wt%, and polyethylene glycol methacrylate was used instead of 4 wt% Was used in an amount of 1.6% by weight.

Comparative Example 4

(In terms of solid content) was used in an amount of 45 wt% instead of 80 wt%, styrene was used in an amount of 44 wt% instead of 16 wt%, and polyethylene glycol methacrylate was used instead of 4 wt% 11% by weight, based on the total weight of the composition.

Comparative Example 5

The procedure of Example 1 was repeated except that styrene was used in an amount of 20 wt% instead of 16 wt% and polyethylene glycol methacrylate was not used in place of 4 wt% in the preparation of the modifier.

[Test Example]

The properties of the specimens prepared in Examples 1 to 2 and Comparative Examples 1 to 3 were measured by the following methods.

* Wet Surface Resistance: Wet surface resistivity was measured using a portable skid resistance tester from Hemel Hempstead, UK. The measurement was carried out using a specimen of 3 cm (width) * 5 cm (length) * 3 mm (thickness) while water was applied to the bottom of the marble.

* Abrasion resistance: Using a NBS Rubber abrasion tester manufactured by Daesung Scientific Co., Ltd., a standard rubber and a specimen specified in ASTM D1630 were placed at a height of 2.5 cm (width) * 2.5 cm (length) * 6 mm (length) Thickness), and the number of revolutions until the thickness was worn to 2.5 mm was measured to calculate the ratio of the number of revolutions of the sample to the number of revolutions of the standard rubber.

* Tensile Strength: The specimens were prepared using ASTM D412 fixture, left at 23 ° C for 24 hours, and then subjected to a test at a speed of 500 mm / min using a 4465 model of INSTRON in the United States of America ASTM D638).

* Tear strength: A specimen was prepared using ASTM D624 (Die C) jig, left at 23 ° C for 24 hours, and then tested at a speed of 200 mm / minute using 4465 model manufactured by Instron, USA (ASTM D638).

* Elongation: A specimen was prepared using ASTM D412 fixture, left at 23 ° C for 24 hours, and then subjected to a test at a speed of 500 mm / minute using a 4465 model manufactured by Instron, USA (ASTM D638).

* Specific gravity: A specimen of 2 cm (width) * 2 cm (length) * 3 mm (thickness) was produced from the sheet produced by the above method, and the density was measured using a model AG245 of METTLER TOLEDO, Respectively.

Furtherance Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Furtherance RR BD 75 75 - 75 75 75 75 SM 24 24 - 24 24 24 24 DVB One One - One One One One Mod RR 80 70 - 80 92 45 80 SM 16 24 - 16 6.4 44 20 PEGMA 4 6 - 4 1.6 11 0 Modifier content in rubber 15 15 0 55 15 15 15 Properties WNP SKID 10 10 10 5 10 5 10 Abrasion resistance NBS 260 270 190 150 210 220 240 The tensile strength Kg / cm2 135 140 99 178 105 147 121 Phosphorus strength Kg / cm2 42 40 30 24 25 28 32 Elongation % 580 560 600 210 480 460 450 importance g / cc 1.05 1.05 1.06 1.02 1.04 1.06 1.05 RR = rubber latex, Mod = modifier, BD = butadiene, SM = styrene
DVB = divinylbenzene, PEGMA = polyethylene glycol methacrylate
WNP = wet road surface resistance,

As shown in Table 1, in the case of the rubber composition containing the modifier according to the present invention (Examples 1 and 2), the abrasion resistance, the tensile strength and the tensile strength were higher than those of Comparative Example 1 It was confirmed that the tear strength was particularly excellent and the wet road surface resistance was equivalent.

When the modifier according to the present invention was contained in excess of the range of the present invention (Comparative Example 2), it was confirmed that the properties such as wet road surface resistance, abrasion resistance, tear strength, elongation and specific gravity were not good.

In addition, when the modifier was produced in the range of the content of the rubber latex according to the present invention (Comparative Examples 3 and 4), the physical properties such as abrasion resistance, tear strength and elongation were poor and the tensile strength was extremely low 3), or the wet road surface resistance was extremely decreased (Comparative Example 4).

Further, it was confirmed that almost all the physical properties such as abrasion resistance, tensile strength, tear strength and elongation were lowered in the case of not containing polyethylene glycol methacrylate (Comparative Example 5) in the production of the modifier.

Thus, according to the present invention, it was confirmed that a rubber composition having excellent properties such as wet road surface resistance, abrasion resistance, tensile strength, tear strength, elongation and specific gravity can be produced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It is also natural.

Claims (13)

delete delete 70 to 80% by weight of rubber latex (based on solids); 16 to 24% by weight of an aromatic vinyl monomer graft-copolymerized with the rubber latex; And 4 to 6% by weight of a polyethylene glycol monomer having a repeating unit of an ethylene oxide unit of 5 to 14, graft-copolymerized with the rubber latex,
Wherein the rubber latex comprises 0.1 to 5% by weight of divinylbenzene based on 100% by weight of rubber latex (based on solids). The method of claim 3,
Wherein the rubber latex is a homopolymer of a conjugated diene monomer or a copolymer of the conjugated diene monomer and an aromatic vinyl monomer. 5. The method of claim 4,
Wherein the conjugated diene monomer is at least one member selected from the group consisting of butadiene, isoprene, and chloroisoprene. 5. The method of claim 4,
Wherein the aromatic vinyl monomer constituting the copolymer of the conjugated dienic monomer and the aromatic vinyl monomer is at least one selected from the group consisting of styrene, alpha methyl styrene, vinyl naphthalene, C1-C3-alkyl substituted styrene and halogen substituted styrene By weight based on the total weight of the rubber composition. The method according to claim 6,
Wherein the aromatic vinyl monomer constituting the copolymer of the conjugated dienic monomer and the aromatic vinyl monomer is used in an amount within a range of 0.1 to 45% by weight based on 100% by weight of the rubber latex (based on solid content) Modifier for composition. delete delete delete delete delete delete