KR101721163B1 - Composition for silicone rubber sponge and manufacturing method for silicone rubber sponge - Google Patents

Abstract

The composition for a silicone rubber sponge of the present invention comprises a first polydiorganosiloxane capped at both ends with a hydroxy group and comprising at least one alkenyl group per molecule and a second polydiorganosiloxane containing at least two alkenyl groups per molecule 100 parts by weight of a polydiorganosiloxane comprising: 0.01 to 20 parts by weight of a thickener; 0.5 to 10 parts by weight of an emulsifier; 0.0001 to 2 parts by weight of a catalyst; 0.001 to 5 parts by weight of a hardening retarder; 20 to 120 parts by weight of water; And 0.1 to 15 parts by weight of a polyhydrogensiloxane containing at least two silicon-bonded hydrogen atoms per molecule.

Description

TECHNICAL FIELD [0001] The present invention relates to a composition for a silicone rubber sponge and a method for manufacturing a silicone rubber sponge,

The present invention relates to a composition for a silicone rubber sponge and a method for producing a silicone rubber sponge.

The silicone rubber sponge is also referred to as foamed silicone rubber, which contains a pyrolytic foaming agent in the siloxane compound, and is heated and vulcanized to form a foam. Such silicone rubber sponge is advantageous in softness, light weight, resilience, flexibility, elasticity and hermeticity. Further, it has excellent heat resistance, cold resistance and weather resistance as compared with an organic rubber sponge, and can be used in a wide range of temperatures, and can be used in various fields such as heat resistant materials and heat insulating materials.

The silicone rubber sponge is generally manufactured by introducing an organic foaming agent, various volatile components and gases. Particularly, the organic foaming agent is mainly composed of a pyrolytic azo compound. When the silicone rubber composition is cured, nitrogen gas is released from the space between the silicone rubber and the foaming agent simultaneously to form a silicone rubber foam.

In this connection, Korean Patent Laid-Open Publication No. 2014-0109794 discloses an alkenyl group-containing polydiorganosiloxane, a polyorganohydrogensiloxane having an average of at least two hydrogen atoms bonded to silicon atoms in the molecule, azobisisobutyronitrile, A composition for a silicone rubber foam comprising an organic foaming agent such as 1,1'-azobis (1-acetoxy-1-phenylethane), a silica powder and a platinum-based metal compound catalyst.

However, azoisobutyronitrile (AIBN) used as an organic foaming agent has problems such as generation of tetramethyl succinonitrile (TMSN) which is an environmentally harmful substance as a side reaction product, poor foaming effect and generation of harmful gas And the silicone rubber sponge molded body manufactured by this method has a disadvantage in that it is difficult to form the molded body from a complicated mold. Further, in the case of such a silicone rubber sponge composition, there is a problem that the mold is contaminated, the appearance is poor, or the pores of the obtained sponge product are uneven.

An object of the present invention is to provide a composition for a silicone rubber sponge which is excellent in weatherability, flame retardancy, chemical resistance, oil resistance and heat resistance.

Another object of the present invention is to provide a composition for a silicone rubber sponge having excellent mechanical strength such as tensile strength, elasticity and compression set.

Still another object of the present invention is to provide a composition for a silicone rubber sponge that is excellent in storage stability, appearance, formability, and processability.

Another object of the present invention is to provide a composition for a silicone rubber sponge which is excellent in environmental friendliness and productivity while preventing mold contamination.

It is still another object of the present invention to provide a method for manufacturing a silicone rubber sponge.

It is still another object of the present invention to provide a method of manufacturing a silicone rubber sponge that prevents molding defects.

One aspect of the present invention relates to a composition for a silicone rubber sponge. Wherein the silicone rubber composition comprises a first polydiorganosiloxane capped at both ends with a hydroxy group and comprising at least one alkenyl group per molecule and a second polydiorganosiloxane containing at least two alkenyl groups per molecule, 100 parts by weight of diorganosiloxane; 0.01 to 20 parts by weight of a thickener; 0.5 to 10 parts by weight of an emulsifier; 0.0001 to 2 parts by weight of a catalyst; 0.001 to 5 parts by weight of a hardening retarder; 20 to 120 parts by weight of water; And 0.1 to 15 parts by weight of a polyhydrogensiloxane containing at least two silicon-bonded hydrogen atoms per molecule.

In an embodiment, the viscosity of the first polydiorganosiloxane is from 100 mPa.s to 120,000 mPa.s (measured at 25.degree. C.), and the viscosity of the second polydiorganosiloxane is from 500 mPa.s to 2,500 Pa.s Measurement standard).

In one embodiment, the thickener comprises at least one of an organic thickener and an inorganic thickener, wherein the organic thickener is selected from the group consisting of polyethylene oxide, sodium polyacrylate, polyvinyl methyl ether, starch, starch derivatives, sodium alginate, sodium alginate derivatives, carboxymethylcellulose , Hydroxyethyl cellulose, ethyl cellulose, and cellulose derivatives, and the inorganic thickener may include at least one of montmorillonite, hectorite, saponite, beellite, zeolite, mica, and perlite.

In one embodiment, the first polydiorganosiloxane and the second polydiorganosiloxane may be included in a weight ratio of 1: 0.1 to 1: 2.

In one embodiment, the catalyst may include at least one of a platinum-based catalyst, a palladium-based catalyst, and a rhodium-based catalyst.

In one embodiment, the cure retardant is selected from the group consisting of 2-methyl-3-butyne-2-ol, 2-phenyl- 3-ethyl-3-butene-1-yne, 3-phenyl-1-hexene-1-yne, 1,5-hexadienyl, 1,6-heptadine, Butene-1-yne, 1,3-divinyltetramethyldisiloxane, 1,3,5,7-tetravinyltetramethylcyclotetrasiloxane, 1,3-divinyl-1,3-diphenyldimethyl (3-methyl-1-butyne-3-oxy) silane, tributylamine, tetramethylethylenediamine, benzotriazole, triphenylphosphine, a sulfur-containing compound, a hydroperoxy compound, Maleic acid derivative-1-ethynylcyclohexanol and 3-methyl-1-pentene-3-ol.

In one embodiment, the silicone rubber sponge composition further comprises 1 to 60 parts by weight of a filler based on 100 parts by weight of the polydiorganosiloxane, and the filler is selected from the group consisting of silica, carbon black, titanium oxide, calcium carbonate, iron oxide, Barium sulfate, magnesium lactate, zinc oxide, aluminum oxide, aluminum hydroxide, and magnesium hydroxide.

Another aspect of the invention relates to a method of making a silicone rubber sponge. The manufacturing method includes the steps of injecting the composition for a silicone rubber sponge into a cavity of a mold and molding the composition to prepare an intermediate molded body; And removing moisture of the intermediate formed body.

In one embodiment, the silicone rubber sponge composition comprises 100 parts by weight of a polydiorganosiloxane, 0.01 to 19.9 parts by weight of a thickener, 0.4 to 9.9 parts by weight of an emulsifier, 0.0001 to 2 parts by weight of a catalyst, 0.001 to 5 parts by weight of a curing retarder, A second agent comprising 0.1 to 15 parts by weight of a polyhydrogensiloxane, 0.01 to 5 parts by weight of a thickener, 0.01 to 1 part by weight of an emulsifier and 0.5 to 2 parts by weight of water, .

In one embodiment, the molding is performed by one or more of extrusion molding, injection molding and compression molding, and the extrusion molding, injection molding and compression molding are performed by pressing the silicone rubber sponge composition at 80 ° C to 100 ° C to vulcanize and cure .

In one embodiment, gas generated in the cavity during the molding is discharged.

The composition for a silicone rubber sponge of the present invention is excellent in weather resistance, flame retardancy, chemical resistance, oil resistance and heat resistance, excellent in mechanical strength such as tensile strength, elasticity and compression set, excellent in storage stability and appearance, Which is excellent in environmental friendliness due to the absence of an organic foaming agent and is excellent in moldability and processability to enable compression and injection molding, can produce a complicated shape product, is excellent in productivity, .

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

One aspect of the invention relates to a composition for a sponge rubber sponge. Wherein the silicone rubber composition comprises a polydiorganosiloxane; Thickener; Emulsifiers; catalyst; Curing retarder; water; And polyhydrogensiloxanes. More specifically, polyesters comprising a first polydiorganosiloxane having both ends capped with a hydroxy group and comprising at least one alkenyl group per molecule and a second polydiorganosiloxane containing at least two alkenyl groups per molecule, 100 parts by weight of diorganosiloxane; 0.01 to 20 parts by weight of a thickener; 0.5 to 10 parts by weight of an emulsifier; 0.0001 to 2 parts by weight of a catalyst; 0.001 to 5 parts by weight of a hardening retarder; 20 to 120 parts by weight of water; And 0.1 to 15 parts by weight of a polyhydrogensiloxane containing at least two silicon-bonded hydrogen atoms per molecule.

Hereinafter, the components of the composition for sponge rubber sponge will be described in more detail.

Polydiorganosiloxane

The polydiorganosiloxane acts as a main agent of the silicone rubber sponge composition.

In the present invention, the polydiorganosiloxane comprises two or more polydiorganosiloxanes which are different from each other. In embodiments, the polydiorganosiloxane comprises a first polydiorganosiloxane capped at both ends with a hydroxy group and comprising at least one alkenyl group per molecule, and a second polydiorgano containing at least two alkenyl groups per molecule Siloxane.

In an embodiment, the alkenyl group may have from 2 to 20 carbon atoms. For example, 2 to 10 carbon atoms. As another example, it may be a vinyl group having two carbon atoms.

In one embodiment, the first polydiorganosiloxane may comprise a structure of Formula 1:

[Chemical Formula 1]

Wherein R ¹ , R ² and R ³ each independently represent a linear or branched alkyl group having 1 to 10 carbon atoms, an aminoalkyl group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, A cycloalkyl group having 3 to 15 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and an alkenyl group having 2 to 20 carbon atoms, and a is an integer of 1 to 500).

Examples of the alkyl group having 1 to 10 carbon atoms in the linear or branched form include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tertiary butyl, n-pentyl, isopentyl, neopentyl, Octyl, nonyl, and decyl.

Examples of the aminoalkyl group having 1 to 10 carbon atoms include methylamino group, dimethylamino group, ethylamino group, diethylamino group, dipropylamino group, and dibutylamino group.

In the specific examples, the hydroxyalkyl group having 1 to 10 carbon atoms includes hydroxymethyl, hydroxyethyl and hydroxypropyl.

Examples of the haloalkyl group having 1 to 20 carbon atoms include fluoroalkyl groups such as trifluoropropyl, heptafluoropentyl, heptafluoroisopentyl, tridecafluorooctyl and heptadecafluorodecyl; And chloroalkyl groups such as chloromethyl, chloroethyl and chloropropyl.

Examples of the cycloalkyl group having 3 to 15 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cyclodecyl, cyclododecyl, butylcyclopropyl, methyl Cyclopentyl, dimethylcyclohexyl, ethyldimethylcycloheptyl, and dimethylcyclooctyl.

In the specific examples, the aryl group having 6 to 12 carbon atoms includes a phenyl group, a tolyl group, a xylyl group and a naphthyl group.

In the specific examples, the aralkyl group having 7 to 20 carbon atoms includes a methylphenyl group, an ethylphenyl group, a methylnaphthyl group, and a dimethylnaphthyl group.

Examples of the alkenyl group having 2 to 20 carbon atoms include vinyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, decynyl, hexadecynyl, and octadecynyl groups.

In one embodiment, the second polydiorganosiloxane may comprise a structure of Formula 2:

(2)

Wherein R ⁴ , R ⁵ and R ⁶ each independently represents a linear or branched alkyl group having 1 to 10 carbon atoms, an aminoalkyl group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, An alkyl group having 3 to 15 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and an alkenyl group having 2 to 20 carbon atoms, and X is an alkenyl group having 2 to 20 carbon atoms B is an integer of 1 to 3, and c is an integer of 1 to 500. [

Examples of the alkyl group having 1 to 10 carbon atoms in the linear or branched form include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tertiary butyl, n-pentyl, isopentyl, neopentyl, Octyl, nonyl, and decyl.

Examples of the aminoalkyl group having 1 to 10 carbon atoms include methylamino group, dimethylamino group, ethylamino group, diethylamino group, dipropylamino group, and dibutylamino group.

In the specific examples, the hydroxyalkyl group having 1 to 10 carbon atoms includes hydroxymethyl, hydroxyethyl and hydroxypropyl.

Examples of the haloalkyl group having 1 to 20 carbon atoms include fluoroalkyl groups such as trifluoropropyl, heptafluoropentyl, heptafluoroisopentyl, tridecafluorooctyl and heptadecafluorodecyl; And chloroalkyl groups such as chloromethyl, chloroethyl and chloropropyl.

Examples of the cycloalkyl group having 3 to 15 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cyclodecyl, cyclododecyl, butylcyclopropyl, methyl Cyclopentyl, dimethylcyclohexyl, ethyldimethylcycloheptyl, and dimethylcyclooctyl.

In the specific examples, the aryl group having 6 to 12 carbon atoms includes a phenyl group, a tolyl group, a xylyl group and a naphthyl group.

In the specific examples, the aralkyl group having 7 to 20 carbon atoms includes a methylphenyl group, an ethylphenyl group, a methylnaphthyl group, and a dimethylnaphthyl group.

Examples of the alkenyl group having 2 to 20 carbon atoms include vinyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, decynyl, hexadecynyl, and octadecynyl groups.

The first and second polydiorganosiloxanes may each include a straight chain structure or a straight chain structure including a side chain. When the polydiorganosiloxane is mixed and used, the shrinkage rate of the sponge of the present invention can be easily controlled and the physical properties can be excellent.

In an embodiment, the viscosity of the first polydiorganosiloxane may be from 100 mPa.s to 120,000 mPa.s (measured at 25 DEG C). The viscosity of the second polydiorganosiloxane may be 500 mPa · s to 2,500 mPa · s (25 ° C measurement standard). Within the above range, the composition for silicone rubber sponge is excellent in moldability and mixing property, and the porous structure is easily formed and crosslinked, and physical properties can be excellent.

In embodiments, the alkenyl groups content of the first and second polydiorganosiloxanes may each be from 0.01 wt% to 5 wt%. In the above range, the crosslinking and curing properties are excellent, and the hardness and physical properties of the composition are excellent. For example, the alkenyl group content of the first and second polydiorganosiloxanes may be 0.05 wt% to 3.5 wt%. For example, the alkenyl group content of the first and second polydiorganosiloxanes may range from 0.1 wt% to 0.5 wt%.

The weight average molecular weight (Mw) of the first polydiorganosiloxane may be 50,000 g / mol to 100,000 g / mol, respectively. Within the above range, the mechanical properties and processability of the present invention can be excellent. For example from 65,000 g / mol to 75,000 g / mol.

The weight average molecular weight (Mw) of the second polydiorganosiloxane may be 15,000 g / mol to 40,000 g / mol, respectively. Within the above range, the mechanical properties and processability of the present invention can be excellent. For example from 20,000 g / mol to 30,000 g / mol.

The first polydiorganosiloxane and the second polydiorganosiloxane may be included in a weight ratio of 1: 0.1 to 1: 2. When the content is within the above range, the shrinkage ratio is improved, the curing property is excellent, and the hardness and physical properties of the composition can be excellent. For example, in a weight ratio of 1: 0.3 to 1: 1.2. For example, in a weight ratio of 1: 0.4 to 1.

Thickener

The thickener is included for the purpose of controlling the viscosity and securing dispersion stability of the silicone rubber sponge composition. The thickener may include at least one of an organic thickener and an inorganic thickener.

The organic thickener may include at least one selected from the group consisting of polyethylene oxide, sodium polyacrylate, polyvinyl methyl ether, starch, starch derivatives, sodium alginate, sodium alginate, carboxymethyl cellulose, hydroxyethyl cellulose, ethyl cellulose and cellulose derivatives.

The inorganic thickener may include at least one of montmorillonite, hectorite, saponite, beellite, zeolite, mica and perlite. The inorganic thickener components may be all natural or synthetic forms.

The organic thickener may be used in a form dispersed in water, which will be described later.

In an embodiment, the thickener may be included in an amount of 0.01 to 20 parts by weight based on 100 parts by weight of the polydiorganosiloxane. In the above range, the viscosity control and the dispersion stability of the composition can be excellent without impairing the physical properties of the rubber composition for sponge. When the thickener is contained in an amount of less than 0.01 part by weight, it is difficult to form a porous phase when the sponge of the present invention is formed. If the thickener is contained in an amount exceeding 20 parts by weight, physical properties of the sponge may be deteriorated. For example, 0.05 to 15 parts by weight. For example, 0.05 to 10 parts by weight.

Emulsifier

The emulsifier is included for the purpose of improving the mixing property and storage stability of the silicone rubber sponge composition. The emulsifier may include at least one of nonionic, cationic, anionic and amphoteric emulsifiers.

The nonionic emulsifier is selected from the group consisting of glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, polyethylene glycol fatty acid esters, polypropylene glycol fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene sorbitan fatty acid esters , Block copolymers of polyoxyethylene and polyoxypropylene, polyoxyethylene alkoxyether, polyoxyethylene alkoxyphenyl ether, and polyoxyethylene fatty acid amide.

The cationic emulsifier may include at least one of an aliphatic amine salt, a quaternary ammonium salt, and an alkylpyridinium salt.

The anionic emulsifier may include at least one of a higher fatty acid salt, a higher alcohol sulfate ester salt, an alkyl benzene sulfonate salt, an alkyl naphthalene sulfonate salt, and a polyethylene glycol sulfate ester salt.

The amphoteric emulsifier may include at least one of carboxybetaine or glycine.

In a specific example, a nonionic emulsifier having little effect on the hydrosilylation reaction can be used.

These emulsifiers may be used alone or in combination of two or more different kinds. In an embodiment, the HLB value of the emulsifier (hydrophilic lipophilic balance, weight average HLB value when used in combination of two or more) may be 1 to 10. The dispersion stability of the silicone rubber sponge composition may be excellent in the above range. For example, the HLB value may be 1.5-6.

The emulsifier may be added in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the polydiorganosiloxane. In the above range, the composition for a silicone rubber sponge may have excellent mixing properties and storage stability. If the amount of the emulsifier is less than 0.5 parts by weight, the mixing and storage stability of the present invention may be deteriorated to form a sponge. When the amount of the emulsifier is more than 10 parts by weight, formation of sponge pores may be uneven and physical properties may be deteriorated. For example, 1 part by weight to 5 parts by weight. For example, 2 to 4 parts by weight.

catalyst

The catalyst is included in the present invention for the purpose of promoting curing reaction (or hydrosilylation reaction) by reaction of an aliphatic unsaturated bond and a hydrogen atom bonded to a silicon atom.

As the catalyst, a conventional catalyst may be used. For example, a platinum group catalyst can be used. For example, one or more of a platinum-based catalyst, a palladium-based catalyst, and a rhodium-based catalyst may be used.

In an embodiment, the platinum-based catalyst may be used by dispersing a platinum component in a thermoplastic resin. At this time, the platinum-based catalyst may contain 0.01 wt% or more of platinum atoms based on the total weight of the platinum-based catalyst. In the specific example, the platinum-based catalyst may be a particulate phase having an average particle size of 0.01 to 500 탆. In the present specification, the term " size " means " maximum length ".

The thermoplastic resin may be composed of a thermoplastic resin having a softening point of 40 ° C to 200 ° C. In the specific example, the thermoplastic resin may be one having a siloxane unit represented by the formula C ₆ H ₅ SiO _3/2 , CH ₃ SiO _3/2 , and (C ₆ H ₅ ) ₂ SiO _2/2 as a main component.

In an embodiment, the platinum catalyst is selected from the group consisting of fine powder platinum, platinum black, chloroplatinic acid, alcohol-modified chloroplatinic acid, chloroplatinic acid-olefin complex, chloroplatinic acid-alkenylsiloxane complex, and chloroplatinic acid-divinyltetramethyldisiloxane complex Or more.

The catalyst is contained in an amount of 0.0001 part by weight to 1 part by weight based on 100 parts by weight of the polydiorganosiloxane. Within the above range, the curing reaction rate of the present invention can be easily controlled. When the catalyst is contained in an amount of less than 0.0001 part by weight, the curing reaction does not proceed easily. When the catalyst is contained in an amount exceeding 1 part by weight, the pore size of the sponge of the present invention is irregularly formed, . For example, 0.0001 part by weight to 0.5 part by weight. For example, 0.001 part by weight to 0.5 part by weight.

Hardening retarder

The curing retarder may be included for the purpose of adjusting the pore size and porosity of the sponge by adjusting the curing rate and the production time of the composition for a silicone rubber sponge of the present invention.

As the curing retarder in the specific examples, a compound having a carbon-carbon double bond or a carbon-carbon triple bond at the terminal may be used. For example, 2-methyl-3-butyn-2-ol, phenylbutynol, 3-methyl-1-butyn-3-ol, 3,5- 1-hexyne-3-ol, 1-ethynylcyclohexanol, 1,5-hexadiyne, 1,6-heptadine, 3,5-dimethyl- 1,3-divinyltetramethyldisiloxane, 1,3,5,7-tetravinyltetramethylcyclotetrasiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-divinyltetramethylcyclotetrasiloxane, (3-methyl-1-butyne-3-oxy) silane, tributylamine, tetramethylethylenediamine, benzotriazole, triphenylphosphine A sulfur-containing compound, a hydroperoxy compound, maleic acid derivative-1-ethynylcyclohexanol and 3-methyl-1-penten-3-ol. A compound having a carbon-carbon triple bond such as 1-ethynylcyclohexanol, 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn- .

In an embodiment, the curing retarder may be included in an amount of 0.001 to 5 parts by weight based on 100 parts by weight of the polydiorganosiloxane. Within the above range, the effect of controlling the curing rate can be excellent without impairing the physical properties of the present invention. For example, 0.01 part by weight to 3 parts by weight. For example, 0.01 part by weight to 1 part by weight.

Polyhydrogen siloxane

The polyhydrogensiloxane is included in the present invention for the purpose of vulcanization (crosslinking), and may include a structure represented by the following general formula (3)

(3)

(Wherein R ⁷ is a linear or branched alkyl group having 1 to 10 carbon atoms, an aminoalkyl group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, An aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 20 carbon atoms and an alkenyl group having 2 to 20 carbon atoms, d is a positive number of 1 to 2.2, e is a positive number of 0.02 to 1 to be).

Examples of the alkyl group having 1 to 10 carbon atoms in the linear or branched form include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tertiary butyl, n-pentyl, isopentyl, neopentyl, Octyl, nonyl, and decyl.

Examples of the aminoalkyl group having 1 to 10 carbon atoms include methylamino group, dimethylamino group, ethylamino group, diethylamino group, dipropylamino group, and dibutylamino group.

In the specific examples, the hydroxyalkyl group having 1 to 10 carbon atoms includes hydroxymethyl, hydroxyethyl and hydroxypropyl.

Examples of the haloalkyl group having 1 to 20 carbon atoms include fluoroalkyl groups such as trifluoropropyl, heptafluoropentyl, heptafluoroisopentyl, tridecafluorooctyl and heptadecafluorodecyl; And chloroalkyl groups such as chloromethyl, chloroethyl and chloropropyl.

Examples of the cycloalkyl group having 3 to 15 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cyclodecyl, cyclododecyl, butylcyclopropyl, methyl Cyclopentyl, dimethylcyclohexyl, ethyldimethylcycloheptyl, and dimethylcyclooctyl.

In the specific examples, the aryl group having 6 to 12 carbon atoms includes a phenyl group, a tolyl group, a xylyl group and a naphthyl group.

In the specific examples, the aralkyl group having 7 to 20 carbon atoms includes a methylphenyl group, an ethylphenyl group, a methylnaphthyl group, and a dimethylnaphthyl group.

Examples of the alkenyl group having 2 to 20 carbon atoms include vinyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, decynyl, hexadecynyl, and octadecynyl groups.

The polyhydrogensiloxane contains two or more silicon-bonded hydrogen atoms per molecule. For example, the polyhydrogensiloxane may have a structure containing two or more silicon-bonded hydrogen atoms at both ends or side chains thereof.

The polyhydrogensiloxane may be in a linear, cyclic or branched form. For example, it may be in a linear form.

In embodiments, the polyhydrogensiloxane may have from 0.1% to 5% silicon-bonded hydrogen groups. When the content is within the above range, vulcanization is easily performed, and the hardness and mechanical strength of the sponge can be suitably formed.

Also, the polyhydrogensiloxane may have a kinematic viscosity measured at 25 캜 of 10 to 5,000 mm 2 / s. The mixing and storage stability can be excellent in the above range. The kinematic viscosity of the present invention is a value measured at 25 占 폚 by an Ostwald viscometer.

In an embodiment, the polyhydrogensiloxane is a copolymer of polymethylhydrogensiloxane having a terminal blocked with a trimethylsiloxy group, dimethylsiloxane having both terminals blocked with a trimethylsiloxy group and methylhydrogenosiloxane, dimethyl A copolymer of dimethylsiloxane and methylhydrogensiloxane blocked with a hydrogensiloxy group, and tetramethyltetrahydrocyclotetrasiloxane.

In an embodiment, the polyhydrogensiloxane is a copolymer of polymethylhydrogensiloxane having a terminal blocked with a trimethylsiloxy group, dimethylsiloxane having both terminals blocked with a trimethylsiloxy group and methylhydrogenosiloxane, dimethyl A copolymer of dimethylsiloxane and methylhydrogensiloxane blocked with a hydrogensiloxy group, and tetramethyltetrahydrocyclotetrasiloxane.

In an embodiment, the polyhydrogen siloxane is included in an amount of 0.1 to 15 parts by weight based on 100 parts by weight of the polydiorganosiloxane. Within the above range, the stability, mechanical strength and physical properties of the present invention can be excellent. When the amount of the polyhydrogensiloxane is less than 0.1 part by weight, the vulcanization reaction of the present invention is not easily carried out and the mechanical strength is lowered. When the amount exceeds 15 parts by weight, the mechanical strength of the present invention is lowered. For example, 0.5 to 10 parts by weight. For example, 1 part by weight to 5 parts by weight.

water

The purpose of the water is to serve as a foaming agent for forming pores and forming a sponge while providing the dispersibility, moldability, and mixing properties of the silicone rubber sponge composition of the present invention. The water may be conventional tap water, ion exchange water or distilled water. For example, ion exchange water can be used.

In an embodiment, the water may be included in an amount of 20 to 130 parts by weight based on 100 parts by weight of the polydiorganosiloxane. Within the above range, the dispersibility, moldability and mixing property of the present invention can be excellent. If the amount of the water is less than 20 parts by weight, the dispersibility, moldability and mechanical strength of the composition for a silicone rubber sponge deteriorate. If the water content exceeds 130 parts by weight, the mechanical strength of the present invention is lowered. For example, 40 parts by weight to 100 parts by weight. For example, 50 to 95 parts by weight.

filling

The composition for a silicone rubber sponge of the present invention may further comprise a filler. The filler may be included for mechanical strength improvement and fluidity control of the silicone rubber sponge composition.

The filler may include at least one of silica, carbon black, titanium oxide (TiO ₂ ), calcium carbonate, iron oxide, magnesium carbonate, barium sulfate, magnesium stearate, zinc oxide, aluminum oxide, aluminum hydroxide and magnesium hydroxide.

The silica may be amorphous or crystalline, and may include at least one of fumed silica and precipitated silica. More specifically, one or more of hydrophobic dry silica, hydrophobic wet silica, hydrophilic dry silica, hydrophilic wet silica and aerosil can be used.

The silica may have a specific surface area (BET method) of 50 m 2 / g to 500 m 2 / g. The mechanical properties of the present invention can be excellent in the specific surface area. For example, 100 m 2 / g to 300 m 2 / g can be used.

In the specific examples, the silica may be at least one of a silane-based surface treatment agent and a silazane-based surface treatment agent. Examples of the silane surface treating agent include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, hexyltrimethoxysilane, Hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, trifluoropropyltrimethoxysilane, hexamethyldisiloxane, trimethylmethoxysilane, ethyltrimethoxysilane, trimethylethoxysilane, and dimethyldiethoxysilane. .

The silazane-based surface treatment agent may include at least one of divinyltetramethyldisilazane, octamethylcyclotetrasilazane, and hexamethyldisilazane.

When the surface treatment is performed with the surface treatment agent, the silica reacts with moisture in the air to form a hydrogen bond while maintaining the appearance and transparency of the present invention, and the increase in plasticity can be suppressed.

The titanium oxide may be a dry titanium oxide.

In an embodiment, the filler may comprise silica, carbon black and aluminum hydroxide in a weight ratio of 1: 0.1 to 2: 0.5 to 2. Within the above range, the effect of increasing the hardness, mechanical strength and heat resistance of the present invention can be excellent.

In an embodiment, the average size of the filler may be between 10 nm and 100 탆. The dispersibility and the mixing property are excellent in the average size, and the mechanical strength and heat resistance of the present invention can be easily ensured. For example, 50 nm to 20 탆.

The filler may be included in an amount of 1 to 60 parts by weight based on 100 parts by weight of the polydiorganosiloxane. Within the above range, the flowability of the present invention can be easily controlled, and mechanical strength and physical properties can be excellent. For example, 5 to 55 parts by weight. For example, 8 to 40 parts by weight.

In a specific example, the silicone rubber sponge composition may be used in one-component or two-component form. For example, a polydiorganosiloxane containing both a first polydiorganosiloxane capped at both ends with a hydroxy group and containing at least one alkenyl group per molecule and a second polydiorganosiloxane containing at least two alkenyl groups per molecule A first agent comprising a siloxane, a siloxane, a siloxane, a siloxane, a siloxane, a siloxane, a siloxane, And a second agent including a polyhydrogensiloxane containing at least two silicon-bonded hydrogen atoms per molecule containing two or more silicon-bonded hydrogen atoms per molecule, a thickener, an emulsifier and water.

In an embodiment, the first agent comprises 100 parts by weight of a polydiorganosiloxane, 0.01 to 19.9 parts by weight of a thickener, 0.4 to 9.9 parts by weight of an emulsifier, 0.0001 to 2 parts by weight of a catalyst, 0.001 to 5 parts by weight of a curing retardant, Parts by weight.

The second agent may include 0.1 to 15 parts by weight of polyhydrogen siloxane, 0.01 to 5 parts by weight of a thickener, 0.01 to 1 part by weight of an emulsifier, and 0.5 to 2 parts by weight of water. When the composition is added in the above-mentioned two-component composition, the process efficiency is improved and the moldability is improved due to the ease of stirring in the mold during the manufacturing process, and the hydrosilylation reaction is prevented from occurring before molding the composition, It can be stored for a long period of time at low temperature.

In an embodiment, the first agent may further include the filler in the above-mentioned content.

Another aspect of the present invention relates to a method for producing a silicone rubber sponge using the composition for a silicone rubber sponge. The method for producing a silicone rubber sponge comprises: an intermediate molding preparation step; And a water removal step. More specifically, the above-described composition for a silicone rubber sponge is injected into a cavity in a mold and molded to produce an intermediate molded body; And removing moisture of the intermediate formed body.

Hereinafter, the method of manufacturing the silicone rubber sponge will be described step by step.

Intermediate molding production step

The above step is a step of injecting the above-mentioned composition for a silicone rubber sponge into a cavity in a mold and molding the same to produce an intermediate molded body.

In embodiments, the composition for the silicone rubber sponge comprises a first polydiorganosiloxane capped at both ends with a hydroxy group and comprising at least one alkenyl group per molecule, and a second polydiorgano comprising at least two alkenyl groups per molecule 100 parts by weight of a polydiorganosiloxane containing a siloxane; 0.01 to 20 parts by weight of a thickener; 0.5 to 10 parts by weight of an emulsifier; 0.0001 to 2 parts by weight of a catalyst; 0.001 to 5 parts by weight of a hardening retarder; 20 to 120 parts by weight of water; And 0.1 to 15 parts by weight of a polyhydrogensiloxane containing two or more silicon-bonded hydrogen atoms per molecule. Since the components are the same as those described above, a detailed description will be omitted.

In preparing the silicone rubber sponge, the composition may be used in one-component form or may be divided into two-component form by the above-mentioned ingredients and contents. The above compositions are mixed and used uniformly before use using a mixing apparatus. The congestion device may be a homomixer, a homo dispenser, a paddle mixer, a planetary mixer, or the like.

The molding may be carried out using one or more methods of extrusion molding, injection molding and compression molding. In an embodiment, the extrusion molding, the injection molding, and the compression molding may be performed by vulcanizing and curing the silicone rubber sponge composition by pressurizing the silicone rubber sponge composition at 80 ° C to 100 ° C. Under these conditions, sponge pores are uniformly formed, and a sponge having excellent physical properties can be produced.

In one embodiment, gas generated inside the cavity can be discharged by heating during the molding. In the specific example, the gas can be discharged to the outside through the gas vent vent or the like provided in the mold. The sponge pores are uniformly formed at the time of discharging the gas, and a sponge having excellent physical properties can be manufactured.

Water removal step

The step is to remove moisture contained in the intermediate formed body. In the embodiment, the moisture contained in the intermediate molded body can be removed at 100 ° C to 200 ° C for 30 minutes to 2 hours. With the above conditions, pores are uniformly formed when water is removed, and a sponge having excellent physical properties can be produced.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. However, the following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples. The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.

Specific specifications of the components used in the above Examples and Comparative Examples are as follows.

(A) a polydiorganosiloxane

(A1) First polydiorganosiloxane: A copolymer of dimethylsiloxane and methylvinylsiloxane having a viscosity of 7,500 mPa 占 퐏 (at 25 占 폚) was used (vinyl group content: 0.069% by weight). (A2) Second polydiorganosiloxane: Polymethylvinylsiloxane having a viscosity of 1,000 mPa 占 퐏 (measurement at 25 占 폚) was used (vinyl group content: 0.3% by weight).

(B) Thickener

(B1) Polyethylene oxide was used as an organic thickener. (B2) Sodium polyacrylate was used as an organic thickener.

(C) Emulsifier

(CI) sorbitan fatty acid ester having a HLB of 4.3 was used as a nonionic emulsifier (Hinon LS-80, Oh sung Chemical Co., Ltd.). (C2) a polyethylene glycol ester having an HLB of 10.6 was used as a nonionic emulsifier (Hipeg 600DO, Oh sung Chemical Co., Ltd.).

(D) H ₂ PtCl ₆ as a platinum-based catalyst (Pt content 0.5 wt%, CAT PL-56 Shin-Etsu Chemical Corporation).

1-ethynyl-1-cyclohexanol of BASF was used as the (E) curing retarder.

(F) Water: Ion exchange water was used.

(G) Polyhydrogensiloxane: A copolymer of dimethylsiloxane and methylhydrogensiloxane having a kinematic viscosity of 200 mm 2 / s capped with trimethylsiloxy groups at both ends of the molecule was used (silicon-bonded hydrogen atom content: 1.4 wt%). .

(H1) Aerosil 200 of hydrophilic dry silica fumed silica having a specific surface area (BET method) of 200 m < 2 > / g was used.

(H2) carbon black having an average size of 10 mu m was used.

(H3) Aluminum hydroxide having an average size of 10 mu m was used.

Example 1

The components (A) to (H) were prepared in the form of a two-part composition of parts A and B according to the ingredients and contents shown in Table 1 below.

The mixture of A part and B part according to Table 1 was mixed to prepare an emulsion type mixture. The mixture was injected into a mold, vulcanized and cured at 90 캜 for 3 minutes by using a press, Lt; / RTI > During the curing, the gas was discharged through a vent provided in the mold. The prepared intermediate molded body was dried in a dry oven at 150 ° C for 1 hour to remove water contained in the intermediate molded body to prepare a silicone rubber sponge specimen.

Example 2

The mixture obtained by stirring the components A and B according to Table 1 was injected into a mold, vulcanized and cured at 90 캜 for 3 minutes, and then injected to prepare an intermediate molded body in a water state. During the curing, the gas was discharged through a vent provided in the mold. The prepared intermediate molded body was dried in a dry oven at 150 ° C for 1 hour to remove water contained in the intermediate molded body to prepare a silicone rubber sponge specimen.

Examples 3 to 4

A silicone rubber sponge specimen was prepared in the same manner as in Example 1, except that part A and part B according to Table 1 were applied.

Comparative Example 1

A silicone rubber sponge specimen was prepared in the same manner as in Example 1, except that part A and part B according to Table 1 were applied.

Comparative Example 2

A silicone rubber sponge specimen was prepared in the same manner as in Example 2 except that part A and part B according to Table 1 were applied.

Comparative Examples 3 to 6

A silicone rubber sponge specimen was prepared in the same manner as in Example 1, except that part A and part B according to Table 1 were applied.

Test Example

(1) Storage stability: The silicone rubber sponges of Examples 1 to 4 and Comparative Examples 1 to 6, which were prepared in a two-part type of part A and part B, B part, respectively, and then observed with naked eyes. Evaluation was made as to whether the mixture was in a homogeneous state or separated from the water phase, and the results are shown in Table 2 below. The composition was evaluated as " stable " if it maintained homogeneity and " separation " if separation was observed.

(2) Density: The density of the silicone rubber sponge specimens of Examples 1 to 4 and Comparative Examples 1 to 6 was measured according to KS M ISO 845, and the results are shown in Table 2 below.

(3) Hardness (Asker C): The hardness of the silicone rubber sponge specimens of Examples 1 to 4 and Comparative Examples 1 to 6 was measured by a Type C hardness tester based on KS M 6518 standard, and is shown in Table 2 below . At this time, a test piece for measuring the hardness of 13 mm was used as the thickness of the test piece.

(4) Tensile strength (kgf / mm < 2 >) and elongation (%): Tensile strength and elongation of the silicone rubber sponge specimens of Examples 1 to 4 and Comparative Examples 1 to 6 were measured according to KS M 6518 Table 2 shows the results. The thickness of the specimen was 6 mm.

(5) Pore state: The cross section of the test piece for hardness measurement according to KS M 6518 prepared in Examples 1 to 4 and Comparative Examples 1 to 6 was observed with naked eyes to find that the uniform pore state of the entire cross section was "uniform" The results are shown in Table 2 below. &Quot; Rupture " is defined as " nonuniformity ", and " rupture " when excessive pores and cracks are observed on the cross section.

(6) Average pore size (占 퐉): A test piece for hardness measurement according to KS M 6518 prepared in Examples 1 to 4 and Comparative Examples 1 to 6 was cut with a blade, and the center of the cut surface was observed with a scanning electron microscope , And the pore size was calculated by averaging the pore sizes of 200 to 300 measured in the area of 0.04 mm 2, and is shown in Table 2 below. The maximum diameter was also measured during the measurement of the average diameter and is shown in Table 2 below.

(7) Shrinkage (%): The length of the test piece obtained by molding each of the molds of Examples 1 to 4 and Comparative Examples 1 to 6 with a length of 80 mm, a width of 160 mm and a thickness of 13 mm was measured, The results are shown in Table 2 below.

[Formula 1]

Shrinkage percentage (%) = [{80-measurement value (mm)} / 80] x 100

(8) Mold Pollution: After the molds used for molding the test pieces for hardness measurement prepared in Examples 1 to 4 and Comparative Examples 1 to 6 were cooled, the surfaces of the cavities were touched with hands to evaluate the presence of deposits. &Quot; Good " when there was no change before molding, and " Contamination "

With reference to the results shown in Table 2, the silicone rubber sponge compositions of Examples 1 to 4 according to the present invention were excellent in storage stability when stored in a two-pack type, had excellent physical properties such as tensile strength and elongation, It was found that the porous sponge was manufactured in the form of a porous sponge having a low porosity, low shrinkage and excellent mold releasing property. On the other hand, in the case of the compositions of Comparative Examples 1 to 6 in which the composition component of the silicone rubber sponge of the present invention was not contained or exceeded the content range, the separation phenomenon occurred during storage, the properties were lowered than in Examples 1 to 4, , The pore state was uneven and the shrinkage rate was increased.

Claims (11)

A first polydiorganosiloxane having both ends capped with a hydroxy group and comprising at least one alkenyl group per molecule and having a viscosity of from 7,500 mPa.s to 120,000 mPa.s (measured at 25 DEG C), and at least two 100 parts by weight of a polydiorganosiloxane comprising a second polydiorganosiloxane having an alkenyl group and having a viscosity of 500 mPa · s to 1,000 mPa · s (measured at 25 ° C);
0.05 to 10 parts by weight of a thickener;
2 to 4 parts by weight of an emulsifier;
0.0001 to 2 parts by weight of a catalyst;
0.01 to 1 part by weight of a hardening retarder;
40 to 100 parts by weight of water;
1 to 5 parts by weight of a polyhydrogensiloxane containing at least two silicon-bonded hydrogen atoms per molecule; And
8 to 40 parts by weight of a filler,
Wherein the first polydiorganosiloxane and the second polydiorganosiloxane are contained in a weight ratio of 1: 0.4 to 1: 1,
Wherein the filler comprises silica, carbon black and aluminum hydroxide in a weight ratio of 1: 0.1 ~ 2: 0.5 ~ 2.
delete The ink composition according to claim 1, wherein the thickener comprises at least one of an organic thickener and an inorganic thickener,
Wherein the organic thickener comprises at least one selected from the group consisting of polyethylene oxide, sodium polyacrylate, polyvinyl methyl ether, starch, starch derivatives, sodium alginate, sodium alginate, carboxymethyl cellulose, hydroxyethyl cellulose, ethyl cellulose and cellulose derivatives,
Wherein the inorganic thickener comprises at least one of montmorillonite, hectorite, saponite, beidellite, zeolite, mica and perlite.
delete The composition for a silicone rubber sponge according to claim 1, wherein the catalyst comprises at least one of a platinum catalyst, a palladium catalyst and a rhodium catalyst.
The curing retardant of claim 1, wherein the curing retardant is selected from the group consisting of 2-methyl-3-butyn-2-ol, 2-phenyl- 3-butene-1-in, 3-ethyl-3-butene-1-in, 3-ethyl- 1,3-divinyltetramethyldisiloxane, 1,3,5,7-tetravinyltetramethylcyclotetrasiloxane, 1,3-divinyl-1,3-di (3-methyl-1-butyne-3-oxy) silane, tributylamine, tetramethylethylenediamine, benzotriazole, triphenylphosphine, sulfur-containing compounds, hydroperoxy A maleic acid derivative-1-ethynylcyclohexanol, and a 3-methyl-1-pentene-3-ol.
delete A first polydiorganosiloxane having both ends capped with a hydroxy group and containing at least one alkenyl group per molecule and having a viscosity of from 7,500 mPa · s to 120,000 mPa · s (measured at 25 ° C.) 100 parts by weight of a polydiorganosiloxane containing a second polydiorganosiloxane having a viscosity of 500 mPa · s to 1,000 mPa · s (measurement at 25 ° C.), 0.05 to 10 parts by weight of a thickener, 2 to 4 A first agent comprising 0.0001 to 2 parts by weight of a catalyst, 0.01 to 1 part by weight of a curing retarder, 40 to 100 parts by weight of water and 8 to 40 parts by weight of a filler, 1 to 5 parts by weight of a polyhydrogensiloxane, 0.01 to 5 parts by weight of a thickener, 0.01 to 1 part by weight of an emulsifier, and 0.5 to 2 parts by weight of a silicone rubber sponge composition according to the present invention is injected into a cavity in a mold to form an intermediate molded body step; And
And removing moisture of the intermediate formed body,
Wherein the first polydiorganosiloxane and the second polydiorganosiloxane are contained in a weight ratio of 1: 0.3 to 1: 1.2,
Wherein the filler comprises silica, carbon black and aluminum hydroxide in a weight ratio of 1: 0.1 ~ 2: 0.5 ~ 2.
delete 9. The method of claim 8, wherein the forming is performed by one or more of extrusion molding, injection molding, and compression molding,
Wherein the extrusion molding, injection molding and compression molding are performed by vulcanizing and curing the silicone rubber sponge composition by pressurizing the silicone rubber sponge composition at 80 ° C to 100 ° C.
The method of manufacturing a silicon rubber sponge according to claim 10, wherein the gas generated in the cavity during the molding is discharged.