JP7103386B2 - Acrylic rubber veil with excellent storage stability and workability - Google Patents

Description

The present invention relates to an acrylic rubber bale having excellent storage stability and processability and a method for producing the same, a rubber mixture obtained by mixing the acrylic rubber veil and a method for producing the same, and a crosslinked rubber product obtained by cross-linking the acrylic rubber veil.

Acrylic rubber is a polymer containing acrylic acid ester as a main component, and is generally known as rubber having excellent heat resistance, oil resistance, and ozone resistance. It is widely used in automobile-related fields and ages as needed. It is used with the addition of an inhibitor.

Such acrylic rubber is usually emulsion-polymerized with the monomer components constituting the acrylic rubber, brought into contact with the obtained emulsion polymerization solution and a coagulant, and the obtained hydrous crumb is dried and then veiled and commercialized. To.

For example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2006-328239) describes a step of obtaining a crumb slurry containing a crumb-like rubber polymer by contacting a polymer latex with a coagulating liquid, and a stirring power of 1 kW / m3 or more. A step of crushing the crumb-shaped rubber polymer contained in the crumb slurry with a mixer having a stirring / crushing function, and dehydration of removing water from the crumb slurry in which the crumb-shaped rubber polymer is crushed to obtain a crumb-shaped rubber polymer. A method for producing a rubber polymer comprising a step and a step of heating and drying a crumb-shaped rubber polymer from which water has been removed is disclosed, and the dried crumb is introduced into a baler in the form of flakes, compressed and veiled. It is stated that it will be polymerized. Further, it is described that it is preferable to adjust the maximum width of the crumb to about 3 to 20 mm for crushing with a mixer having a stirring / crushing function. As the rubber polymer used here, an unsaturated nitrile-conjugated diene copolymer latex obtained by emulsification polymerization is specifically shown, and an ethyl acrylate / n-butyl acrylate copolymer and an ethyl acrylate / It has been shown that it can be applied to a polymer composed only of an acrylate such as an n-butyl acrylate / 2-methoxyethyl acrylate copolymer. However, acrylic rubber composed only of acrylate has a problem that it is inferior in crosslinked rubber characteristics such as strength characteristics, heat resistance, and compression set resistance.

Examples of acrylic rubber having a reactive group having excellent crosslinked rubber properties include ethyl acrylate, n-butyl acrylate and mono n-butyl fumarate in Patent Document 2 (International Publication No. 2018/116828). Acrylic rubber latex, which is emulsified with sodium lauryl sulfate as an emulsifier, polyethylene glycol monostearate, and water and emulsified in the presence of a polymerization initiator until the polymerization conversion rate reaches 95%, is combined with magnesium sulfate. After adding it to an aqueous solution with a polymer flocculant dimethylamine-ammonia-epichlorohydrin polycondensate, it is stirred at 85 ° C. to form a crumb slurry, and then the crumb slurry is washed once with water and then 100 mesh. A method of recovering a crumb-shaped acrylic rubber by passing the entire amount through a wire net to capture only the solid content is disclosed. According to this method, it is described that the obtained hydrous crumb is dehydrated by centrifugation or the like, dried at 50 to 120 ° C. by a band dryer or the like, introduced into a baler, compressed and veiled. There is. However, this method has problems such as a large number of semi-solidified hydrous crumbs generated in the coagulation reaction and a large amount of them adhering to the coagulation tank, and problems such as insufficient removal of coagulants and emulsifiers by washing. Even if it is produced, there are problems such as poor storage stability, poor processability in a vanbury or the like, and a long kneading time.

As the acrylic rubber containing an anti-aging agent, for example, Patent Document 3 (International Publication No. 2018/139466 pamphlet) simply contains ethyl acrylate, n-butyl acrylate, monobutyl fumarate and the like. The body component was stirred with pure water, sodium lauryl sulfate and polyoxyethylene dodecyl ether to obtain a monomeric emulsion, and ferrous sulfate, sodium alcorbate and potassium persulfate aqueous solution were continuously added dropwise over 3 hours. Then, in the emulsified polymer solution having a polymerization conversion rate of 95%, a 50% by weight aqueous dispersion of stearyl 3- (3,5-tert-butyl-4-hydroxyphenyl) propionate (0.2% by weight lauryl) was added. 50 parts of stearyl propionate (3,5-di-tert-butyl-4-hydroxyphenyl) added and mixed with 50 parts of an aqueous solution of sodium sulfate) or 2,4-bis [(octylthio) methyl] -6- Add and mix 50 parts by weight of 2,4-bis [(octylthio) methyl] -6-methylphenol to 50 parts by weight of an aqueous dispersion of 50% by weight of methylphenol (0.2% by weight of sodium lauryl sulfate aqueous solution). After adding (prepared by the above), the temperature was raised to 85 ° C. and coagulated with sodium sulfate to generate hydrous crumbs, and then the produced hydrous crumbs were washed with industrial water 4 times and acid washed at pH 3 1 After washing the pure water once and once, it is dried in a hot air dryer at 160 ° C. for 10 minutes to prevent the polymerization equipment from becoming dirty during polymerization and to have a crumb-like shape with excellent initial mechanical strength. A method for producing acrylic rubber is disclosed. Further, it is described that the hydrous crumb washed by the screw type Oshida dryer can be dried at 150 ° C. or higher according to this method. However, in addition to heat resistance, it has been required to improve processability and storage stability in a harsh environment.

Regarding the amount of gel of acrylic rubber, for example, Patent Document 4 (Japanese Patent No. 3599962) contains two radical-reactive unsaturated groups having different reactivity with 95 to 99.9% by weight of alkyl acrylate or alkoxyalkyl acrylate. Acrylate rubber having a gel content of 5% by weight or less of an acetone-insoluble matter obtained by copolymerizing 0.1 to 5% by weight of the above-mentioned polymerizable monomer in the presence of a radical polymerization initiator, reinforcing property. An acrylic rubber composition having an extruding rate, a die well, a surface surface, and the like, which is composed of a filler and an organic peroxide-based sulfide, and has excellent extrusion processability is disclosed. The acrylic rubber having a very small gel fraction used here is an acrylic rubber having a high gel fraction (60%) obtained in a normal acidic region (pH 4 before polymerization, pH 3.4 after polymerization). On the other hand, it is obtained by adjusting the pH of the polymerization solution to 6 to 8 with sodium hydrogen carbonate or the like. Specifically, after adding water, sodium lauryl sulfate and polyoxyethylene nonylphenyl ether, sodium carbonate and boric acid as emulsifiers and adjusting the temperature to 75 ° C., t-butyl hydroperoxide, longalite, disodium ethylenediamine tetraacetate, Ferrous sulfate was added (pH at this time was 7.1), then the monomer components of ethyl acrylate and allyl methacrylate were added dropwise to emulsify and polymerize, and the obtained emulsion (pH 7) was subjected to an aqueous sodium sulfate solution. Acrylic rubber is obtained by salting using and washing with water and drying. However, acrylic rubber containing (meth) acrylic acid ester as the main component has problems in handling such as decomposition in the neutral to alkaline region and inferior storage stability, and emulsion polymerization is carried out by changing the pH from neutral to alkaline. The acrylic rubber used had the problem of being inferior in mechanical strength due to the loss of reactive groups (crosslink points) such as carboxyl groups, epoxy groups, and chlorine atoms.

Further, in Patent Document 5 (International Publication No. 2018/143101 pamphlet), a (meth) acrylic acid ester and an ion-crosslinkable monomer are emulsion-polymerized and have a complex viscosity at 100 ° C. ([η] 100 ° C.). Is 3500 or less, and the ratio of the complex viscosity at 60 ° C. ([η] 60 ° C.) to the complex viscosity at 100 ° C. ([η] 100 ° C.) ([η] 100 ° C./[η] 60 ° C.) is A technique for improving the extrusion moldability of a rubber composition containing a reinforcing agent and a cross-linking agent, particularly the discharge amount, the discharge length, and the surface texture by using acrylic rubber having a thickness of 0.8 or less is disclosed. The gel amount of the tetrahydrofuran-insoluble portion of the acrylic rubber used in the same technique is 80% by weight or less, preferably 5 to 80% by weight, and preferably exists as much as possible in the range of 70% or less, and the gel amount is large. It is stated that if it is less than 5%, the extrudability deteriorates. The weight average molecular weight (Mw) of the acrylic rubber used is 200,000 to 1,000,000, and when the weight average molecular weight (Mw) exceeds 1,000,000, the viscoelasticity of the acrylic rubber is high. It is stated that it is too much to be preferable. However, in recent years, there has been an increasing demand for acrylic rubber that balances high strength with processability during kneading such as Banbury, and improvement in storage stability has also been required.

Japanese Unexamined Patent Publication No. 2006-328239 International Publication No. 2018/116828 Pamphlet International Publication No. 2018/139466 Pamphlet Japanese Patent No. 3599962 International Publication No. 2018/143101 Pamphlet

The present invention has been made in view of such an actual situation, and an acrylic rubber bale having excellent storage stability and processability and a method for producing the same, a rubber mixture obtained by mixing the acrylic rubber veil and a method for producing the same, and a method for producing the same. It is an object of the present invention to provide the rubber crosslinked product.

As a result of diligent research in view of the above problems, the present inventors have increased the molecular weight distribution in the polymer region with a specific molecular weight having a reactive group, and a gel containing a specific antioxidant and insoluble in a specific solvent. It was found that the acrylic rubber veil, which has a specific amount, is highly excellent in storage stability and workability.

We also found that the content, structure, melting point and molecular weight of the phenolic anti-aging agent of acrylic rubber veil, the monomer composition of acrylic rubber, the type of reactive group, the polymerization, and the complex viscoelasticity at a specific temperature. It has been found that the effect of the present invention is remarkably improved by specifying the elasticity, specific gravity, gel amount, pH, ash content, ash component amount and component ratio.

The present inventors also wash a hydrous crumb produced by coagulating a monomer component containing a reactive group-containing monomer after emulsion polymerization and dehydrating it, and then substantially free of water (specifically included). It was found that an acrylic rubber bale having excellent storage stability and processability can be easily produced by drying to (water content) and then bale-forming.

The present inventors also use a specific screw type extruder to dry the washed water-containing crumb to a specific water content that is substantially free of water, and melt-knead the specific anti-aging agent and acrylic rubber in a state. As a result, it was found that an acrylic rubber bale that is uniformly finely dispersed and has significantly improved storage stability and heat resistance can be produced. It is difficult to dry the water-containing crumbs with a screw-type extruder to a state where they are substantially free of water with acrylic rubber, which has a high specific heat. It has been found that an acrylic rubber bale having excellent storage stability and heat resistance can be stably produced by specifying and bale the sheet laminate.

The present inventors also further emulsify the specific anti-aging agent added to the emulsion polymerization solution with warm water and an emulsifier, and specify the production temperature, emulsifier concentration and pH of the specific anti-aging agent-containing emulsion. We have found that an acrylic rubber bale with excellent storage stability and heat resistance can be produced.

In addition, when the polymerization conversion rate of emulsion polymerization is increased in order to improve the strength characteristics of acrylic rubber having a reactive group, the amount of gel insoluble in a specific solvent rapidly increases and the processability deteriorates. However, by drying the washed hydrous crumb with a screw type extruder to a state where it is substantially free of water (specific water content) and melt-kneading, the gel amount of the specific solvent-insoluble portion that rapidly increased disappears and is reactive. We have found that it is possible to produce an acrylic rubber bale with a highly balanced strength property and workability that does not reduce the number of groups.

The present inventors have further found that the water resistance of the acrylic rubber veil is improved by squeezing (dehydrating) water from the water-containing crumb after washing to a specific water content.

The present inventors have completed the present invention based on these findings.

Thus, according to the present invention, it has a reactive group and has a weight average molecular weight (Mw) of 100,000 to 5,000,000, and the ratio (Mz /) of the z average molecular weight (Mz) to the weight average molecular weight (Mw). Provided is an acrylic rubber veil comprising an acrylic rubber having a Mw) of 1.3 or more, containing a phenolic antioxidant, and having a gel amount of 50% by weight or less of an insoluble methyl ethyl ketone.

In the acrylic rubber veil of the present invention, the content of the phenolic antiaging agent is preferably 0.001 to 15% by weight.

In the acrylic rubber veil of the present invention, the phenolic antiaging agent is preferably a hindered phenolic antiaging agent.

In the acrylic rubber veil of the present invention, the melting point of the phenolic antiaging agent is preferably 150 ° C. or lower.

In the acrylic rubber veil of the present invention, the molecular weight of the phenolic antiaging agent is preferably in the range of 100 to 1000.

In the acrylic rubber veil of the present invention, the acrylic rubber is at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester, and a reactive group-containing simple substance. It is preferably composed of an ester and, if necessary, other monomers copolymerizable.

In the acrylic rubber veil of the present invention, the reactive group is preferably at least one functional group selected from the group consisting of a carboxyl group, an epoxy group and a halogen group.

In the acrylic rubber veil of the present invention, the weight average molecular weight (Mw) is preferably in the range of 1,000,000 to 5,000,000.

In the acrylic rubber veil of the present invention, the complex viscosity ([η] 100 ° C.) at 100 ° C. is preferably in the range of 1500 to 6000 Pa · s.

In the acrylic rubber veil of the present invention, the ratio of the complex viscosity at 100 ° C. ([η] 100 ° C.) to the complex viscosity at 60 ° C. ([η] 60 ° C.) ([η] 100 ° C./[η] 60 ° C. ) Is preferably 0.5 or more.

In the acrylic rubber veil of the present invention, the ratio of the complex viscosity at 100 ° C. ([η] 100 ° C.) to the complex viscosity at 60 ° C. ([η] 60 ° C.) ([η] 100 ° C./[η] 60 ° C. ) Is preferably 0.8 or more.

The acrylic rubber veil of the present invention preferably has a specific gravity of 0.7 or more.

The acrylic rubber veil of the present invention preferably has a specific gravity of 0.8 or more.

In the acrylic rubber veil of the present invention, the gel amount of the insoluble methyl ethyl ketone is preferably 5% by weight or less.

In the acrylic rubber veil of the present invention, the pH is preferably 6 or less.

In the acrylic rubber veil of the present invention, the ash content is preferably 0.5% by weight or less.

In the acrylic rubber veil of the present invention, the content of at least one element selected from the group consisting of sodium, sulfur, calcium, magnesium and phosphorus in the ash content is 50% by weight or more in proportion to the total ash content. preferable.

In the acrylic rubber veil of the present invention, the total amount of magnesium and phosphorus in the ash content is preferably 50% by weight or more as a ratio to the total ash content.
In the acrylic rubber veil of the present invention, the ratio of magnesium to phosphorus in the ash ([Mg] / [P]) is preferably in the range of 0.4 to 2.5.

In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is obtained by emulsion polymerization.
In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is polymerized using a phosphate ester salt or a sulfate ester salt as an emulsifier.
In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is polymerized using a redox catalyst composed of a radical generator and a reducing agent.
In the acrylic rubber veil of the present invention, the acrylic rubber is preferably polymerized to a polymerization conversion rate of 80% by weight or more.
In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is obtained by adding a phenolic antiaging agent to the emulsion polymerization solution after emulsion polymerization, and then coagulating and drying the acrylic rubber.
In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is obtained by solidifying and drying the emulsion polymerization solution with an alkali metal salt or a metal salt of Group 2 of the periodic table.
In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is a dried water-containing crumb formed after solidifying the emulsion polymerization solution.
In the acrylic rubber bale of the present invention, the proportion of the water-containing crumbs produced that pass through a JIS sieve having a mesh size of 6.7 mm but do not pass through a JIS sieve having a mesh size of 710 μm is preferably 20% by weight or more.
In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is a hydrous crumb washed with warm water and then dried.
In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is a water-containing crumb that has been dehydrated to a water content of 1 to 50% by weight and then dried.
In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is dried under reduced pressure after solidification.
In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is melt-kneaded and dried after solidification.
In the acrylic rubber veil of the present invention, it is preferable that the melt kneading is carried out in a state where the melt kneading is substantially free of water.
In the acrylic rubber veil of the present invention, it is preferable that the drying is performed by a screw type extruder.
In the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber veil is cooled at a cooling rate of 50 ° C./hr or more after the drying.

Thus, according to the present invention, there is also provided a rubber mixture obtained by mixing a filler and a cross-linking agent with the acrylic rubber veil.
In the rubber mixture of the present invention, the filler is preferably a reinforcing filler.
In the rubber mixture of the present invention, the filler is preferably carbon black.
In the rubber mixture of the present invention, the filler is preferably silica.
In the rubber mixture of the present invention, the cross-linking agent is preferably a polyvalent amine compound, an ammonium carboxylic acid salt, a metal dithiocarbamic acid salt or a triazine thiol compound.
In the rubber mixture of the present invention, it is preferable that the anti-aging agent is further mixed.
In the rubber mixture of the present invention, the anti-aging agent is preferably an amine-based anti-aging agent.

According to the present invention, there is also provided a method for producing a rubber mixture, which comprises mixing a filler , a cross-linking agent and, if necessary, an antiaging agent with the acrylic rubber veil using a mixer.

The present invention also provides a method for producing a rubber mixture in which an acrylic rubber veil, a filler and, if necessary, an antiaging agent are mixed and then a cross-linking agent is mixed.

According to the present invention, a rubber crosslinked product obtained by cross-linking the rubber mixture is further provided.
In the rubber crosslinked product of the present invention, it is preferable that the cross-linking is a primary cross-linking and a secondary cross-linking.
According to the present invention, there is further provided a method for producing a rubber crosslinked product in which the above rubber mixture is primarily crosslinked and then secondarily crosslinked.

According to the present invention, an acrylic rubber bale having excellent storage stability and processability and a method for producing the same, a rubber mixture obtained by mixing the acrylic rubber veil and a method for producing the same, and a crosslinked rubber product obtained by cross-linking the acrylic rubber bale and the same . A manufacturing method is provided.

It is a figure which shows typically an example of the acrylic rubber manufacturing system used for manufacturing the acrylic rubber veil which concerns on one Embodiment of this invention. It is a figure which shows the structure of the screw type extruder of FIG. It is a figure which shows the structure of the transport type cooling apparatus used as the cooling apparatus of FIG.

The acrylic rubber sheet of the present invention has a reactive group, has a weight average molecular weight (Mw) of 100,000 to 5,000,000, and has a ratio of z average molecular weight (Mz) to weight average molecular weight (Mw) (Mz). It is characterized by being made of acrylic rubber having a / Mw) of 1.3 or more, containing a phenolic antioxidant, and having a gel amount of 50% by weight or less of an insoluble methyl ethyl ketone.

<Monomer component>
The acrylic rubber veil of the present invention is made of acrylic rubber having a reactive group.

The reactive group is appropriately selected according to the intended use without any particular limitation, but preferably at least one functional group selected from the group consisting of a carboxyl group, an epoxy group and a halogen group, more preferably a carboxyl group. At least one functional group selected from the group consisting of a group, an epoxy group and a chlorine atom, particularly preferably a carboxyl group, an epoxy group, and most preferably a carboxyl group, can highly improve the cross-linking properties of the acrylic rubber veil. Is. Further, as the reactive group, when it is an ionic reactive group such as a carboxyl group or an epoxy group, the water resistance can be particularly improved, which is preferable. As the acrylic rubber having such a reactive group, a reactive group may be imparted to the acrylic rubber by a post-reaction, but a copolymer of a reactive group-containing monomer is preferable.

The acrylic rubber constituting the acrylic rubber veil of the present invention preferably contains (meth) acrylic acid ester, and is selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester. It preferably contains at least one (meth) acrylic acid ester. In the present invention, "(meth) acrylic acid ester" is used as a general term for esters of acrylic acid and / or methacrylic acid.

Specific examples of the acrylic rubber having a preferable reactive group include at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester, and a reactive group. Examples thereof include those composed of a contained monomer and other monomers copolymerizable as needed.

The (meth) acrylic acid alkyl ester is not particularly limited, but usually has a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 12 carbon atoms, preferably an alkyl having 1 to 8 carbon atoms (meth). ) Acrylic acid alkyl ester, more preferably a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 6 carbon atoms.

Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, n-propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, and n- (meth) acrylic acid. Butyl, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate and the like, ethyl (meth) acrylate, (meth) acrylate n-butyl is preferable, and ethyl acrylate and n-butyl acrylate are more preferable.

The (meth) acrylic acid alkoxyalkyl ester is not particularly limited, but usually has a (meth) acrylic acid alkoxyalkyl ester having 2 to 12 alkoxyalkyl groups, preferably having 2 to 8 alkoxyalkyl groups (meth). ) Acrylic acid alkoxyalkyl ester, more preferably a (meth) acrylic acid alkoxy ester having an alkoxyalkyl group having 2 to 6 carbon atoms.

Specific examples of the (meth) acrylic acid alkoxyalkyl ester include methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, methoxybutyl (meth) acrylate, and (meth) acrylic. Examples thereof include ethoxymethyl acid, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate and the like. Among these, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate and the like are preferable, and methoxyethyl acrylate and ethoxyethyl acrylate are more preferable.

At least one (meth) acrylic acid ester selected from the group consisting of these (meth) acrylic acid alkyl esters and (meth) acrylic acid alkoxyalkyl esters can be used alone or in combination of two or more, and acrylic. The proportion in the rubber is usually 50 to 99.99% by weight, preferably 70 to 99.9% by weight, more preferably 80 to 99.5% by weight, and most preferably 87 to 99% by weight. If the amount of (meth) acrylic acid ester in the monomer component is excessively small, the weather resistance, heat resistance, and oil resistance of the obtained acrylic rubber may decrease, which is not preferable.

The reactive group-containing monomer is appropriately selected depending on the intended use without any particular limitation, but usually has at least one functional group selected from the group consisting of a carboxyl group, an epoxy group and a halogen group. A monomer having at least one functional group selected from the group consisting of a monomer, a carboxyl group, an epoxy group and a chlorine atom is preferable, and a monomer having an ionic reactive group such as a carboxyl group and an epoxy group is more preferable. Preferably, a monomer having a carboxyl group is particularly preferable.

The monomer having a carboxyl group is not particularly limited, but an ethylenically unsaturated carboxylic acid can be preferably used. Examples of the ethylenically unsaturated carboxylic acid include ethylenically unsaturated monocarboxylic acid, ethylenically unsaturated dicarboxylic acid, and ethylenically unsaturated dicarboxylic acid monoester, and among these, ethylenically unsaturated dicarboxylic acid monoester. It is preferable that the ester can further enhance the compression-resistant permanent strain resistance when the acrylic rubber is used as a rubber crosslinked product.

The ethylenically unsaturated monocarboxylic acid is not particularly limited, but an ethylenically unsaturated monocarboxylic acid having 3 to 12 carbon atoms is preferable, for example, acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, and the like. Cinnamic acid and the like can be mentioned.

The ethylenically unsaturated dicarboxylic acid is not particularly limited, but an ethylenically unsaturated dicarboxylic acid having 4 to 12 carbon atoms is preferable, and examples thereof include butenedioic acid such as fumaric acid and maleic acid, itaconic acid, and citraconic acid. Can be mentioned. The ethylenically unsaturated dicarboxylic acid includes those existing as an anhydride.

The ethylenically unsaturated dicarboxylic acid monoester is not particularly limited, but usually, an ethylenically unsaturated dicarboxylic acid having 4 to 12 carbon atoms and an alkyl monoester having 1 to 12 carbon atoms, preferably 4 to 6 carbon atoms. The ethylenically unsaturated dicarboxylic acid of the above and an alkyl monoester having 2 to 8 carbon atoms, more preferably an alkyl monoester having 2 to 6 carbon atoms of buthendioic acid having 4 carbon atoms.

Specific examples of the ethylenically unsaturated dicarboxylic acid monoester include monomethyl fumarate, monoethyl fumarate, mono n-butyl fumarate, monomethyl maleate, monoethyl maleate, mono n-butyl maleate, monocyclopentyl fumarate, and fumarate. Butendionic acid monoalkyl esters such as monocyclohexyl acid, monocyclohexenyl fumarate, monocyclopentyl maleate, monocyclohexyl maleate; itaconic acids such as monomethyl itaconate, monoethyl itaconate, monon-butyl itaconate, monocyclohexyl itacone Examples thereof include monoalkyl esters; among these, mono n-butyl fumarate and mono n-butyl maleate are preferable, and mono n-butyl fumarate is particularly preferable.

Examples of the monomer having an epoxy group include an epoxy group-containing (meth) acrylic acid ester such as glycidyl (meth) acrylate; and an epoxy group-containing vinyl ether such as allyl glycidyl ether and vinyl glycidyl ether.

Examples of the monomer having a halogen group include an unsaturated alcohol ester of a halogen-containing saturated carboxylic acid, a (meth) acrylic acid haloalkyl ester, a (meth) acrylic acid haloacyloxyalkyl ester, and a (meth) acrylic acid (haloacetylcarbamoyl). Oxy) alkyl esters, halogen-containing unsaturated ethers, halogen-containing unsaturated ketones, halomethyl group-containing aromatic vinyl compounds, halogen-containing unsaturated amides, haloacetyl group-containing unsaturated monomers and the like can be mentioned.

Examples of the unsaturated alcohol ester of the halogen-containing saturated carboxylic acid include vinyl chloroacetate, vinyl 2-chloropropionate, and allyl chloroacetate. Examples of the (meth) acrylic acid haloalkyl ester include chloromethyl (meth) acrylic acid, 1-chloroethyl (meth) acrylic acid, 2-chloroethyl (meth) acrylic acid, 1,2-dichloroethyl (meth) acrylic acid, and the like. Examples thereof include 2-chloropropyl (meth) acrylic acid, 3-chloropropyl (meth) acrylic acid, and 2,3-dichloropropyl (meth) acrylic acid. Examples of the (meth) acrylic acid haloacyloxyalkyl ester include (meth) acrylic acid 2- (chloroacetoxy) ethyl, (meth) acrylic acid 2- (chloroacetoxy) propyl, and (meth) acrylic acid 3- (chloroacetoxy). ) Propyl, 3- (hydroxychloroacetoxy) propyl (meth) acrylate and the like. Examples of the (meth) acrylic acid (haloacetylcarbamoyloxy) alkyl ester include 2- (chloroacetylcarbamoyloxy) ethyl (meth) acrylic acid and 3- (chloroacetylcarbamoyloxy) propyl (meth) acrylic acid. Be done. Examples of the halogen-containing unsaturated ether include chloromethyl vinyl ether, 2-chloroethyl vinyl ether, 3-chloropropyl vinyl ether, 2-chloroethyl allyl ether, 3-chloropropyl allyl ether and the like. Examples of the halogen-containing unsaturated ketone include 2-chloroethyl vinyl ketone, 3-chloropropyl vinyl ketone, 2-chloroethyl allyl ketone and the like. Examples of the halomethyl group-containing aromatic vinyl compound include p-chloromethylstyrene, m-chloromethylstyrene, o-chloromethylstyrene, and p-chloromethyl-α-methylstyrene. Examples of the halogen-containing unsaturated amide include N-chloromethyl (meth) acrylamide. Examples of the haloacetyl group-containing unsaturated monomer include 3- (hydroxychloroacetoxy) propyl allyl ether and p-vinylbenzyl chloroacetic acid ester.

These reactive group-containing monomers are used alone or in combination of two or more, and the proportion in the acrylic rubber is usually 0.01 to 20% by weight, preferably 0.1 to 10% by weight. , More preferably 0.5 to 5% by weight, and most preferably 1 to 3% by weight.

The other monomer used as needed is not particularly limited as long as it can be copolymerized with the above-mentioned monomer. For example, aromatic vinyl, ethylenically unsaturated nitrile, acrylamide-based monomer, and the like. Olefin-based monomers and the like. Examples of aromatic vinyl include styrene, α-methylstyrene, divinylbenzene and the like. Examples of the ethylenically unsaturated nitrile include acrylonitrile and methacrylonitrile. Examples of the acrylamide-based monomer include acrylamide and methacrylamide. Examples of other olefin-based monomers include ethylene, propylene, vinyl acetate, ethyl vinyl ether, and butyl vinyl ether.

These other monomers are used alone or in combination of two or more, and the proportion in the acrylic rubber is usually 0 to 30% by weight, preferably 0 to 20% by weight, and more preferably 0. It is in the range of ~ 15 parts by weight, most preferably 0 to 10 parts by weight.

<Acrylic rubber>
The acrylic rubber constituting the acrylic rubber veil of the present invention is characterized by having a reactive group. The content of the reactive group may be appropriately selected according to the purpose of use, but is usually 0.001 to 5% by weight, preferably 0.01 to 3% by weight, based on the weight ratio of the reactive group itself. Workability, strength characteristics, compression set resistance, oil resistance, cold resistance, water resistance, etc. are preferably in the range of 0.05 to 1% by weight, particularly preferably 0.1 to 0.5% by weight. The characteristics are highly balanced and suitable.

Specific examples of the acrylic rubber constituting the acrylic rubber veil of the present invention include at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester. It consists of a reactive group-containing monomer and, if necessary, other copolymerizable monomers, and the proportions in each acrylic rubber are (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester. At least one (meth) acrylic acid ester selected from the group consisting of is usually 50 to 99.99% by weight, preferably 70 to 99.9% by weight, more preferably 80 to 99.5% by weight, and particularly preferably. Is in the range of 87 to 99% by weight, and the amount of the reactive group-containing monomer is usually 0.01 to 20% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight. It is particularly preferably in the range of 1 to 3% by weight, and other monomers are usually 0 to 30% by weight, preferably 0 to 20% by weight, more preferably 0 to 15% by weight, and particularly preferably 0 to 10% by weight. It is in the range of% by weight. By setting the ratio of these monomers constituting the acrylic rubber within this range, the object of the present invention can be highly achieved, and when the acrylic rubber veil is used as a crosslinked product, the water resistance and compression set resistance are remarkably improved. It is improved and suitable.

The weight average molecular weight (Mw) of the acrylic rubber constituting the acrylic rubber veil of the present invention is an absolute molecular weight measured by GPC-MALS, which is 100,000 to 5,000,000, preferably 500,000 to 4,000. Workability, strength characteristics, and strength characteristics of the acrylic rubber veil when mixed when it is in the range of 000, more preferably 700,000 to 3,000,000, and most preferably 1,000,000 to 2,500,000. It is suitable because the compression resistance permanent strain characteristics are highly balanced.

The ratio (Mz / Mw) of the z average molecular weight (Mz) and the weight average molecular weight (Mw) of the acrylic rubber constituting the acrylic rubber veil of the present invention is an absolute molecular weight that emphasizes the high molecular weight region measured by GPC-MALS. When the distribution is in the range of 1.3 or more, preferably 1.4 to 5, more preferably 1.5 to 2, the processability and strength characteristics of the acrylic rubber bale are highly balanced and the physical properties change during storage. Is suitable because it can alleviate.

The glass transition temperature (Tg) of the acrylic rubber constituting the acrylic rubber veil of the present invention is not particularly limited, but is usually 20 ° C. or lower, preferably 10 ° C. or lower, and more preferably 0 ° C. or lower. The lower limit of the glass transition temperature (Tg) is not particularly limited, but is usually −80 ° C. or higher, preferably −60 ° C. or higher, and more preferably −40 ° C. or higher. By setting the glass transition temperature to the lower limit or higher, the oil resistance and heat resistance can be improved, and by setting the glass transition temperature to the upper limit or lower, the cold resistance and workability can be improved.

The content of acrylic rubber in the acrylic rubber veil of the present invention is appropriately selected depending on the intended use, but is usually 85% by weight or more, preferably 90% by weight or more, more preferably 95% by weight or more, and particularly preferably 95% by weight or more. It is 97% by weight or more, most preferably 98% by weight or more. The acrylic rubber content in the acrylic rubber bale is the amount of ash that the emulsifier and coagulant used in the emulsion polymerization have not completely removed from the total amount of the acrylic rubber bale, and is added to prevent liquid aging dispersed in the acrylic rubber bale. It is the amount minus the amount.

<Anti-aging agent>
The acrylic rubber veil of the present invention is characterized by containing a phenolic anti-aging agent.

The phenolic anti-aging agent used is not particularly limited as long as it is usually used as an anti-aging agent for rubber, but preferably when it is a hindered phenol-based anti-aging agent, it has storage stability. It is suitable because the effect of heat resistance can be highly achieved. In the present invention, the hindered phenol-based antioxidant refers to a phenol-based antioxidant having bulky substituents on both sides of the phenol group, and the bulky substituents on both sides include an isobutyl group and t. -Butyl group, preferably t-butyl group.

The melting point of the phenolic antiaging agent is not particularly limited, but is usually 150 ° C. or lower, preferably 100 ° C. or lower, more preferably 90 ° C. or lower, particularly preferably 80 ° C. or lower, and most preferably 70 ° C. or lower. It is suitable because it has excellent uniform fine dispersibility with acrylic rubber during melt-kneading and can highly improve the storage stability and heat resistance of the acrylic rubber veil.

The molecular weight of the phenolic anti-aging agent is not particularly limited, but when it is usually 250 to 1000, preferably 300 to 800, and more preferably 350 to 600, it is excellent in uniform fine dispersibility with acrylic rubber. It is suitable because it can highly improve the heat resistance and storage stability of the bale.

Examples of the hindered phenolic anti-aging agent include 2,6-di-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, and 2,6-di-t-butyl-α-dimethyl. Amino-p-cresol, butyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, hexyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, Octyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, decyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, 3- (4-hydroxy) Dodecyl -3,5-di-t-butylphenyl) propionate, octadecyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, 3- (4-hydroxy-3,5-diisopropyl) Heptyl propionate (phenyl), octyl 3- (4-hydroxy-3,5-diisopropylphenyl) propionate, dodecyl 3- (4-hydroxy-3,5-diisopropylphenyl) propionate 3- (4-hydroxy-3, Octadecyl 5-diisopropylphenyl) propionate, 4,4'-methylenebis (2,6-dibutylphenol), 2,6-di-t-butyl-4- (4,6-bis (octylthio) -1,3 Examples thereof include 5-triazine-2-ylamino) phenol, preferably butyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, 3- (4-hydroxy-3,5-). Hexyl di-t-butylphenyl) propionate, octyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, 3- (4-hydroxy-3,5-di-t-butylphenyl) ) Decyl propionate, dodecyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, octadecyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, etc. Preferably, octyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, decyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, 3-( Dodecyl 4-hydroxy-3,5-di-t-butylphenyl) propionate and octadecyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate.

Examples of the phenol-based anti-aging agent other than the hindered phenol-based anti-aging agent include styrenated phenols such as butylhydroxyanisole and mono (or di or tri) (α-methylbenzyl) pheonol. 2,2'-Methylene-bis (6-α-methyl-benzyl-p-cresol), 2,2'-methylene-bis (4-methyl-6-t-butylphenol), alkylated bisphenol, 2,4- Bis [(octylthio) methyl] -6-methylphenol, 2,2'-thiobis- (4-methyl-6-t-butylphenol), 4,4'-thiobis- (6-t-butyl-o-cresol) And the like, preferably 2,4-bis [(octylthio) methyl] -6-methylphenol.

These phenolic anti-aging agents can be used alone or in combination of two or more. The content of the phenolic antioxidant in the acrylic rubber veil is not particularly limited, but is usually 0.001 to 15% by weight, preferably 0.01 to 10% by weight, and more preferably 0.1 to 5% by weight. , Particularly preferably in the range of 0.3 to 3% by weight, most preferably in the range of 0.5 to 2% by weight.

The acrylic rubber veil of the present invention may contain other anti-aging agents other than the phenol-based anti-aging agent as long as the object of the present invention is not impaired.

<Acrylic rubber veil>
The acrylic rubber veil of the present invention is characterized by being made of the acrylic rubber, containing the antiaging agent, and having a specific gel amount of a specific solvent-insoluble component.

The size of the acrylic rubber veil of the present invention is not particularly limited, but the width is usually in the range of 100 to 800 mm, preferably 200 to 500 mm, more preferably 250 to 450 mm, and the length is usually 300 to 1200 mm. The height is usually in the range of 400 to 1000 mm, more preferably 500 to 800 mm, and the height is usually in the range of 50 to 500 mm, preferably 100 to 300 mm, more preferably 150 to 250 mm.

The gel amount of the acrylic rubber veil of the present invention is the insoluble content of methyl ethyl ketone, which is 50% by weight or less, more preferably 30% by weight or less, particularly preferably 10% by weight or less, and most preferably 5% by weight or less. , Workability is highly improved and is suitable. The amount of gel, which is the insoluble matter of methyl ethyl ketone in the acrylic rubber veil, is related to the processability at the time of kneading such as Banbury, but the characteristics of the amount of gel differ depending on the solvent used, and in particular, THF (tetrahydrofuran) is insoluble. It did not correlate with the amount of gel in.

The specific gravity of the acrylic rubber veil of the present invention is not particularly limited, but is usually 0.7 to 1.5, preferably 0.8 to 1.4, and more preferably 0.9 to 1.3. , Especially preferably in the range of 0.95 to 1.25, and most preferably in the range of 1.0 to 1.2, the storage stability is highly excellent and suitable.

The pH of the acrylic rubber veil of the present invention is not particularly limited, but is usually 6 or less, preferably 2 to 6, more preferably 2.5 to 5.5, and particularly preferably 3 to 5. Sometimes storage stability is highly improved and suitable.

The water content of the acrylic rubber veil of the present invention is not particularly limited, but is usually vulcanized when it is less than 1% by weight, preferably 0.8% by weight or less, and more preferably 0.6% by weight or less. The characteristics are optimized, and the characteristics such as heat resistance and water resistance are highly excellent and suitable.

The ash content of the acrylic rubber veil of the present invention is not particularly limited, but is usually 0.5% by weight or less, preferably 0.4% by weight or less, more preferably 0.3% by weight or less, and particularly preferably. When it is 0.2% by weight or less, most preferably 0.15% by weight or less, it is excellent in storage stability and water resistance and is suitable.

The lower limit of the ash content of the acrylic rubber bale produced by the present invention is not particularly limited, but is usually 0.0001% by weight or more, preferably 0.0005% by weight or more, and more preferably 0.001% by weight. % Or more, particularly preferably 0.005% by weight or more, most preferably 0.01% by weight or more, the metal adhesion is suppressed and the workability is excellent and suitable.
The amount of ash in which the storage stability, water resistance and metal adhesion of the acrylic rubber veil of the present invention are highly balanced is usually 0.0001 to 0.5% by weight, preferably 0.0005 to 0.4% by weight. It is more preferably in the range of 0.001 to 0.3% by weight, particularly preferably 0.005 to 0.2% by weight, and most preferably 0.01 to 0.15% by weight.

The amount of at least one element selected from the group consisting of sodium, sulfur, phosphorus, magnesium and calcium in the ash content of the acrylic rubber veil produced by the present invention is usually 30% by weight or more, preferably 30% by weight or more, as a ratio to the total ash content. Is preferably 50% by weight or more, more preferably 70% by weight or more, in which metal adhesion, water resistance and storage stability are highly balanced.

The total amount of sodium and sulfur in the ash content of the acrylic rubber veil of the present invention is stored when it is 30% by weight or more, preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 80% by weight or more. It has excellent stability and water resistance and is suitable.

The ratio of sodium to sulfur ([Na] / [S]) in the ash content of the acrylic rubber veil of the present invention is 0.4 to 2.5, preferably 0.6 to 2, preferably 0 by weight. When it is in the range of .8 to 1.7, more preferably 1 to 1.5, the water resistance is highly excellent and suitable.

The total amount of magnesium and phosphorus in the ash content of the acrylic rubber veil of the present invention is not particularly limited, but is usually 30% by weight or more, preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 80% by weight or more. When the weight is 100% or more, the storage stability and water resistance are highly excellent and suitable.

The ratio of magnesium to phosphorus ([Mg] / [P]) in the ash content of the acrylic rubber veil of the present invention is a weight ratio and is not particularly limited, but is usually 0.4 to 2.5, preferably 0. Storage stability and water resistance are in the range of .4 to 1.3, more preferably 0.4 to 1, particularly preferably 0.45 to 0.75, and most preferably 0.5 to 0.7. Highly excellent and suitable.

The complex viscosity ([η] 60 ° C.) of the acrylic rubber veil of the present invention at 60 ° C. is not particularly limited, but is usually 15,000 Pa · s or less, preferably 2000 to 10,000 Pa · s. When it is preferably in the range of 2500 to 7000 Pa · s, and most preferably 2700 to 5500 Pa · s, it is excellent in processability, oil resistance and shape retention.

The complex viscosity ([η] 100 ° C.) of the acrylic rubber veil of the present invention at 100 ° C. is not particularly limited, but is usually 1500 to 6000 Pa · s, preferably 2000 to 5000 Pa · s, and more preferably 2500. When it is in the range of about 4000 Pa · s, most preferably 2500 to 3500 Pa · s, it is excellent in processability, oil resistance, and shape retention.

The ratio of the complex viscosity ([η] 100 ° C.) of the acrylic rubber veil of the present invention at 100 ° C. to the complex viscosity ([η] 60 ° C.) at 60 ° C. ([η] 100 ° C./[η] 60 ° C.) Is not particularly limited, but is usually 0.5 or more, preferably 0.6 or more, more preferably 0.7 or more, particularly preferably 0.8 or more, and most preferably 0.83 or more. Further, the ratio ([η] 100 ° C./[η] 60 ° C.) of the complex viscosity coefficient at 100 ° C. ([η] 100 ° C.) and the complex viscosity coefficient at 60 ° C. ([η] 60 ° C.) is usually 0. Workability, oil resistance, and workability, oil resistance, and when the range is 5 to 0.99, preferably 0.5 to 0.98, more preferably 0.6 to 0.95, and most preferably 0.75 to 0.93. The shape retention is highly balanced and suitable.

The Mooney viscosity (ML1 + 4,100 ° C.) of the acrylic rubber veil of the present invention is not particularly limited, but is usually processed when it is in the range of 10 to 150, preferably 20 to 100, and more preferably 25 to 70. It is suitable because its properties and strength characteristics are highly balanced.

<Manufacturing method of acrylic rubber veil>
The method for producing the acrylic rubber bale of the present invention is not particularly limited, but for example, at least one () selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester. A monomer component consisting of a meta) acrylic acid ester, a reactive group-containing monomer, and other monomers copolymerizable as needed is emulsified with water and an emulsifier and emulsified and polymerized in the presence of a polymerization catalyst. An emulsion polymerization step of obtaining an emulsion polymerization solution, an antiaging agent addition step of adding a phenolic antiaging agent to the obtained emulsion polymerization solution, and an emulsion polymerization solution to which a phenolic antiaging agent is added are brought into contact with the coagulation liquid. A coagulation step to generate a hydrous crumb, a washing step to wash the produced hydrous crumb, a dehydration step to squeeze the water out of the washed hydrous crumb using a dehydrator, and a dehydrated hydrocramb to be dried to have a water content of less than 1% by weight. It can be easily produced by including a drying step of obtaining the dried rubber of the above and a bale step of bale-forming the obtained dried rubber.

(Emulsion polymerization process)
The emulsion polymerization step in the method for producing an acrylic rubber veil of the present invention comprises at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester, and reactivity. It is characterized in that a monomer component consisting of a group-containing monomer and other monomers copolymerizable as needed is emulsionized with water and an emulsifier and emulsion-polymerized in the presence of a polymerization catalyst to obtain an emulsion polymerization solution. And.

The monomer component used is the same as that described in the monomer component, and the amount used may be appropriately selected so as to have the monomer composition of the acrylic rubber constituting the acrylic rubber veil. good.

The emulsifier used for emulsion polymerization is not particularly limited, and examples thereof include an anionic emulsifier, a cationic emulsifier, and a nonionic emulsifier, and preferably an anionic emulsifier is included.

The anionic emulsifier is not particularly limited, for example, salts of fatty acids such as myristic acid, palmitic acid, oleic acid, linolenic acid; alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate; sulfate esters such as sodium lauryl sulfate. Phosphate ester salts such as salts and polyoxyalkylene alkyl ether phosphate ester salts; alkyl sulfosuccinates and the like can be mentioned. Among these anionic emulsifiers, phosphoric acid ester salts and sulfate ester salts are preferable, and phosphoric acid ester salts are particularly preferable. Suitable phosphate salts include, for example, sodium lauryl phosphate, potassium lauryl phosphate, sodium polyoxyalkylene alkyl ether phosphate and the like. In addition, examples of suitable sulfates include sodium lauryl sulfate, ammonium lauryl sulfate, sodium myristyl sulfate, sodium laureth sulfate, sodium polyoxyethylene alkyl sulfate, sodium polyoxyethylene alkylaryl sulfate, and the like. Sodium lauryl sulfate is particularly suitable.

Examples of the cationic emulsifier include alkyltrimethylammonium chloride, dialkylammonium chloride, and benzylammonium chloride.

The nonionic emulsifier is not particularly limited, but for example, a polyoxyalkylene fatty acid ester such as polyoxyethylene stearate ester; a polyoxyalkylene alkyl ether such as polyoxyethylene dodecyl ether; and a polyoxy such as polyoxyethylene nonylphenyl ether. Alkylene alkylphenol ether; polyoxyethylene sorbitan alkyl ester and the like can be mentioned, and polyoxyalkylene alkyl ether and polyoxyalkylene alkyl phenol ether are preferable, and polyoxyethylene alkyl ether and polyoxyethylene alkyl phenol ether are more preferable.

Each of these emulsifiers can be used alone or in combination of two or more, and the amount used is usually 0.01 to 10 parts by weight, preferably 0, with respect to 100 parts by weight of the monomer component. It is in the range of 1 to 5 parts by weight, more preferably 1 to 3 parts by weight.

As a method of mixing the monomer component, water and emulsifier, a conventional method may be followed, and examples thereof include a method of stirring the monomer, emulsifier and water using a stirrer such as a homogenizer or a disk turbine. .. The amount of water used is usually in the range of 10 to 750 parts by weight, preferably 50 to 500 parts by weight, and more preferably 100 to 400 parts by weight with respect to 100 parts by weight of the monomer component.

The polymerization catalyst used is not particularly limited as long as it is usually used in emulsion polymerization, and for example, a redox catalyst composed of a radical generator and a reducing agent can be used.

Examples of the radical generator include peroxides and azo compounds, and peroxides are preferable. As the peroxide, an inorganic peroxide or an organic peroxide is used.

Examples of the inorganic peroxide include sodium persulfate, potassium persulfate, hydrogen peroxide, ammonium persulfate and the like. Among these, potassium persulfate, hydrogen peroxide and ammonium persulfate are preferable, and potassium persulfate is particularly preferable. preferable.

The organic peroxide is not particularly limited as long as it is a known organic peroxide used in emulsion polymerization. For example, 2,2-di (4,5-di- (t-butylperoxy) cyclohexyl) propane. , 1-di- (t-hexyl peroxy) cyclohexane, 1,1-di- (t-butyl peroxy) cyclohexane, 4,4-di- (t-butyl peroxy) n-butyl valerate, 2, 2-Di- (t-butylperoxy) butane, t-butylhydroperoxide, cumenehydroperoxide, diisopropylbenzenehydroperoxide, paramentanhydroperoxide, benzoyl peroxide, 1,1,3,3-tetraethyl Butylhydroperoxide, t-butylcumyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, di (2-t-butylperoxyisopropyl) benzene, dicumyl peroxide, diisobutyryl peroxide , Di (3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, disuccinate peroxide, dibenzoyl peroxide, di (3-methylbenzoyl) peroxide, benzoyl (3-methylbenzoyl) peroxide , Diisobutyryl peroxydicarbonate, di-n-propyl peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, 1,1,3,3-tetramethylbutyl Peroxyneodecanate, t-hexylperoxypivarate, t-butylperoxyneodecanate, t-hexylperoxypivarate, t-butylperoxypivarate, 2,5-dimethyl-2,5-di (2-Ethylhexanoylperoxy) hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanate, t-hexylperoxy-2-ethylhexanate, t-butylperoxy-3 , 5,5-trimethylhexanate, t-hexyl peroxyisopropyl monocarbonate, t-butylperoxyisopropyl monocarbonate, t-buylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5- Di (benzoylperoxy) hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxybenzoate, 2,5-dimethyl-2,5-di ( Examples thereof include t-butylperoxy) hexane, and among these, diisopropylbenzene hydroperoxide, cumene hydroperoxide, paramentan hydroperoxide, benzoyl peroxide and the like are preferable.

Examples of the azo compound include azobisisoptironitrile, 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis [2- (2-imidazolin-2-yl) propane, 2,2. '-Azobis (Propane-2-Carboamidine), 2,2'-Azobis [N- (2-carboxyethyl) -2-methylpropaneamide], 2,2'-Azobis {2- [1- (2- (2- (2-) Hydroxyethyl) -2-imidazolin-2-yl] propane}, 2,2'-azobis (1-imino-1-pyrrolidino-2-methylpropane) and 2,2'-azobis {2-methyl-N- [ 1,1-bis (hydroxymethyl) -2-hydroxyethyl] propanamide} and the like.

Each of these radical generators can be used alone or in combination of two or more, and the amount used is usually 0.0001 to 5 parts by weight, preferably 0.0001 to 5 parts by weight, based on 100 parts by weight of the monomer component. It is in the range of 0.0005 to 1 part by weight, more preferably 0.001 to 0.5 parts by weight.

As the reducing agent, any one used in the redox catalyst of emulsion polymerization can be used without particular limitation, but in the present invention, it is particularly preferable to use at least two kinds of reducing agents. As the at least two types of reducing agents, for example, a combination of a metal ion compound in a reduced state and another reducing agent is suitable.

The metal ion compound in the reduced state is not particularly limited, and examples thereof include ferrous sulfate, sodium hexamethylenediamine tetraacetate, and ferrous naphthenate, and among these, ferrous sulfate is preferable. These reduced metal ion compounds can be used alone or in combination of two or more, and the amount used is usually 0.000001 to 0. With respect to 100 parts by weight of the monomer component. It is in the range of 01 parts by weight, preferably 0.00001 to 0.001 parts by weight, and more preferably 0.00005 to 0.0005 parts by weight.

The reducing agent other than the metal ion compound in the reduced state is not particularly limited, but is, for example, ascorbic acid such as ascorbic acid, sodium ascorbate, potassium ascorbate or a salt thereof; Elysorbic acid such as potassium acid or a salt thereof; sulfite such as sodium hydroxymethane sulfite; sodium sulfite, potassium sulfite, sodium hydrogen sulfite, aldehyde sodium hydrogen sulfite, potassium hydrogen sulfite sulfite; sodium pyrosulfite, potassium pyrosulfite Pyrosulfites such as sodium bisulfite and potassium hydrogensulfite; thiosulfates such as sodium thiosulfite and potassium thiosulfite; Pyrophosphoric acid or a salt thereof; pyrophosphate or a salt thereof such as pyrosulfite, sodium pyrophosphate, potassium pyrosulfite, sodium bisulfite, potassium bisulfite, etc .; sodium formaldehyde sulfoxylate and the like. Among these, alcorbic acid or a salt thereof, sodium formaldehyde sulfoxylate and the like are preferable, and ascorbic acid or a salt thereof is particularly preferable.

The reducing agents other than the metal ion compounds in the reduced state can be used alone or in combination of two or more, and the amount used is usually 0.001 with respect to 100 parts by weight of the monomer component. The range is from 1 part by weight, preferably 0.005 to 0.5 parts by weight, and more preferably 0.01 to 0.3 parts by weight.

A preferred combination of the metal ion compound in the reduced state and the other reducing agent is ferrous sulfate and ascorbic acid or a salt thereof and / or sodium formaldehyde sulfoxylate, more preferably ferrous sulfate and ascorbate. And / or sodium formaldehyde sulfoxylate, most preferably a combination of ferrous sulfate and alcorbate. At this time, the amount of ferrous sulfate used is usually 0.000001 to 0.01 parts by weight, preferably 0.00001 to 0.001 parts by weight, more preferably 0.00001 parts by weight, based on 100 parts by weight of the monomer component. In the range of 0.00005 to 0.0005 parts by weight, the amount of ascorbic acid or a salt thereof and / or sodium formaldehyde sulfoxylate used is usually 0.001 to 1 part by weight with respect to 100 parts by weight of the monomer component. It is preferably in the range of 0.005 to 0.5 parts by weight, more preferably 0.01 to 0.3 parts by weight.

The amount of water used in the emulsion polymerization reaction may be limited to that used during the emulsionization of the monomer component, but is usually 10 to 1000 parts by weight, preferably 50 parts by weight, based on 100 parts by weight of the monomer component used in the polymerization. It is adjusted to be in the range of up to 500 parts by weight, more preferably 80 to 400 parts by weight, and most preferably 100 to 300 parts by weight.

The emulsion polymerization reaction may be carried out according to a conventional method, and may be a batch type, a semi-batch type, or a continuous type. The polymerization temperature and the polymerization time are not particularly limited and can be appropriately selected from the type of polymerization initiator used and the like. The polymerization temperature is usually in the range of 0 to 100 ° C., preferably 5 to 80 ° C., more preferably 10 to 50 ° C., and the polymerization time is usually 0.5 to 100 hours, preferably 1 to 10 hours.

The polymerization conversion rate of the emulsion polymerization reaction is not particularly limited, but is excellent in the strength characteristics of the acrylic rubber bale produced when it is usually 80% by weight or more, preferably 90% by weight or more, and more preferably 95% by weight or more. Moreover, there is no monomeric odor and it is suitable. A polymerization inhibitor may be used to terminate the polymerization.

(Anti-aging agent addition process)
The step of adding an antioxidant in the method for producing an acrylic rubber veil of the present invention is characterized by adding a phenolic antioxidant to the emulsion polymerization solution after the emulsion polymerization.

The amount of the phenolic antioxidant used may be appropriately selected so as to be the content of the phenolic antioxidant in the acrylic rubber veil of the present invention, and is usually selected with respect to 100 parts by weight of the monomer component. 0.001 to 15 parts by weight, preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, particularly preferably 0.3 to 3 parts by weight, most preferably 0.5 to 2 parts by weight. Is the range of.

The method of adding the phenolic antioxidant to the emulsion polymerization solution is not particularly limited. For example, the phenolic antioxidant is emulsified with an emulsifier and water and added as a phenolic antioxidant-containing emulsion. As a result, the anti-emulsifying agent can be easily dispersed in the acrylic rubber, and the anti-emulsifying agent can be further finely dispersed in the screw type extruder to maximize the anti-aging effect, which is suitable.

The method of emulsifying the phenol-based anti-aging agent is not particularly limited, but usually, after making an emulsion with water and an emulsifier, the phenol-based anti-aging agent is added and stirred until uniformly dispersed. Can be manufactured.

The water for emulsifying the phenolic antiaging agent is preferably warm water, and the temperature is usually 40 ° C. or higher, preferably 50 to 90 ° C., more preferably 60 to 80 ° C. The anti-aging agent is suitable because it can be easily emulsified and uniformly dispersed.

The temperature of water for emulsifying the phenol-based anti-aging agent is also equal to or higher than the melting point of the phenol-based anti-aging agent used, preferably melting point + 5 ° C. or higher, more preferably melting point + 10 ° C. or higher. It is suitable because the agent can be easily emulsified and uniformly dispersed.

The emulsifier for emulsifying the phenolic antioxidant is not particularly limited, but the same emulsifier used when emulsifying the monomer component can be used to isolate the acrylic rubber in the subsequent step. It is stable and suitable on the above. Specific examples thereof include anionic emulsifiers, cationic emulsifiers, nonionic emulsifiers, etc., preferably anionic emulsifiers, more preferably phosphoric acid ester salts, sulfate ester salts, and particularly preferably phosphoric acid ester salts. ..

The amount of the emulsifier used for emulsifying the phenolic anti-aging agent may be appropriately selected depending on the molecular weight, melting point, SP value, etc. of the anti-aging agent to be used, but with respect to the emulsion of water and the emulsifier. , Usually in the range of 1% by weight or more, preferably 3 to 20% by weight, more preferably 5 to 15% by weight, particularly preferably 1 to 5% by weight, most preferably 1.5 to 3% by weight. The anti-aging agent is suitable because it can be easily emulsified and uniformly dispersed.

The stirring time for emulsifying the phenolic anti-aging agent is not particularly limited to the time until the anti-aging agent is uniformly dispersed, but it is usually 1 hour or more, preferably 1 to 5 hours, preferably 1 to 5 hours. Is in the range of 1 to 4 hours, more preferably 1 to 3 hours.

In the phenol-based anti-aging agent-containing emulsion added to the emulsion polymerization solution thus obtained, the phenol-based anti-aging agent is uniformly dispersed. The uniform dispersibility of the phenol-based anti-aging agent in the phenol-based anti-aging agent-containing emulsion can be determined, for example, as follows. The glass container that was once filled with the phenol-based anti-aging agent-containing emulsion and then removed was allowed to stand, and the wall surface of the glass container after the adhered phenol-based anti-aging agent-containing emulsion hung down on the wall surface was observed and was not contaminated. Those with good uniform dispersion can be judged as those with white powder attached, and those with white powder attached can be judged as poor uniform dispersion. The phenolic anti-aging agent-containing emulsion once uniformly dispersed is unlikely to re-coagulate even if it is allowed to stand, but if it becomes poorly dispersed, it can be used after being stirred again and readjusted.

The phenol-based anti-aging agent content of the phenol-based anti-aging agent-containing emulsion is appropriately selected depending on the intended use, but is usually 10 to 80% by weight, preferably 20 to 60% by weight, and more preferably 30 to 45% by weight. When it is%, the storage stability and heat resistance of the acrylic rubber bale can be highly improved, which is suitable.

The emulsifier concentration of the phenolic antioxidant-containing emulsion is not particularly limited, but is usually 0.1% by weight or more, preferably 1 to 40% by weight, preferably 2 to 30% by weight, more preferably 3 to 15% by weight. A high degree of balance between storage stability, heat resistance and water resistance of the acrylic rubber veil is particularly preferably in the range of 4 to 12% by weight, most preferably 5 to 10% by weight, and most preferably 6 to 8% by weight. Can be suitable.

The pH of the phenolic anti-aging agent-containing emulsion is not particularly limited, but is usually 6 or less, preferably 2 to 6, more preferably 3 to 6, and the storage stability of the acrylic rubber veil. It has excellent heat resistance and is suitable.

The method of adding the phenol-based anti-aging agent or the phenol-based anti-aging agent-containing emulsion to the emulsion polymerization solution is not particularly limited and may follow a conventional method.

(Coagulation process)
The coagulation step in the method for producing an acrylic rubber veil of the present invention is a step of bringing the emulsion polymerization solution to which the phenolic antiaging agent is added into contact with the coagulation liquid to form a hydrous crumb.

The solid content concentration of the emulsion polymerization solution used in the coagulation step is not particularly limited, but is usually adjusted to the range of 5 to 50% by weight, preferably 10 to 45% by weight, and more preferably 20 to 40% by weight. To.

The coagulant used is not particularly limited, but a metal salt is usually used. Examples of the metal salt include alkali metals, Group 2 metal salts of the Periodic Table, and other metal salts, preferably alkali metal salts, Group 2 metal salts of the Periodic Table, and more preferably Group 2 of the Periodic Table. A metal salt, particularly preferably a magnesium salt.

Examples of the alkali metal salt include sodium salts such as sodium chloride, sodium nitrate and sodium sulfate; potassium salts such as potassium chloride, potassium nitrate and potassium sulfate; lithium salts such as lithium chloride, lithium nitrate and lithium sulfate. Among these, sodium salts are preferable, and sodium chloride and sodium sulfate are particularly preferable.

Examples of the Group 2 metal salt of the periodic table include magnesium chloride, calcium chloride, magnesium nitrate, calcium nitrate, magnesium sulfate, calcium sulfate and the like, and calcium chloride and magnesium sulfate are preferable.

Other metal salts include, for example, zinc chloride, titanium chloride, manganese chloride, iron chloride, cobalt chloride, nickel chloride, aluminum chloride, tin chloride, zinc nitrate, titanium nitrate, manganese nitrate, iron nitrate, cobalt nitrate, nickel nitrate. , Aluminum nitrate, tin nitrate, zinc sulfate, titanium sulfate, manganese sulfate, iron sulfate, cobalt sulfate, nickel sulfate, aluminum sulfate, tin sulfate and the like.

Each of these coagulants can be used alone or in combination of two or more, and the amount used is usually 0.01 to 100 parts by weight, preferably 0.% by weight, based on 100 parts by weight of the monomer component. It is in the range of 1 to 50 parts by weight, more preferably 1 to 30 parts by weight. When the coagulant is in this range, the acrylic rubber can be sufficiently coagulated, and the compression-resistant permanent strain resistance and water resistance when the acrylic rubber veil is crosslinked can be highly improved, which is preferable.

The coagulant concentration of the coagulant used is usually in the range of 0.1 to 20% by weight, preferably 0.5 to 15% by weight, more preferably 1 to 10% by weight, and particularly preferably 1.5 to 5% by weight. It is preferable that the particle size of the hydrous crumb generated in the above case can be uniformly focused in a specific region.

The temperature of the coagulating liquid is not particularly limited, but is preferably 40 ° C. or higher, preferably 40 to 90 ° C., more preferably 50 to 80 ° C., to form a uniform water-containing crumb.

The contact between the emulsion polymerization solution and the coagulation liquid is not particularly limited, but for example, a method of adding the emulsion polymerization solution to the stirred coagulation liquid, or adding the coagulation liquid to the stirred emulsion polymerization liquid. Any of the methods may be used, but the method of adding the emulsion polymerization solution to the agitated coagulating liquid remarkably improves the cleaning efficiency of the emulsifier and the coagulant by uniformly and focusing the shape and the crumb diameter of the water-containing crumb to be produced. It is suitable.

The stirring speed (rotation speed) of the coagulated liquid being stirred is represented by the rotation speed of the stirring blade of the stirring device provided in the coagulation bath in the present invention, but is usually 100 rpm or more, preferably 200 to 1000 rpm, more preferably. Is in the range of 300 to 900 rpm, particularly preferably 400 to 800 rpm.

Regarding this rotation speed, it is preferable that the rotation speed at which the coagulating liquid is vigorously stirred to some extent is preferable because the water-containing crumb particle size to be generated can be made small and uniform. It is possible to suppress the formation of large and small ones, and by setting the amount to the upper limit or less, the coagulation reaction can be more easily controlled.

The peripheral speed of the agitated coagulant is represented by the linear velocity of the outer circumference of the stirring blade of the agitator provided in the coagulation bath, but the water-containing crumb particle size generated when the coagulant is vigorously agitated to a certain degree. The peripheral speed is usually 0.5 m / s or more, preferably 1 m / s or more, more preferably 1.5 m / s or more, particularly preferably 2 m / s or more, and most preferably 2. It is 5 m / s or more. On the other hand, the upper limit of the peripheral speed is not particularly limited, but is usually solidified when it is 50 m / s or less, preferably 30 m / s or less, more preferably 25 m / s or less, and most preferably 20 m / s or less. It is suitable because the reaction can be easily controlled.

It is produced by setting the above conditions of the coagulation reaction in the coagulation step (contact method, solid content concentration of emulsion polymer, concentration and temperature of coagulation liquid, rotation speed and peripheral speed of coagulation liquid at the time of stirring, etc.) within a specific range. The shape and clam diameter of the hydrous clam are uniform and focused, and the removal of emulsifiers and coagulants during washing and dehydration is remarkably improved, which is suitable.

The hydrous crumb thus produced preferably satisfies the following (A) to (O). The JIS sieve complies with the provisions of the Japanese Industrial Standards (JIS Z 8801-1).
(A) The proportion of hydrous crumbs that do not pass through a JIS sieve with an opening of 9.5 mm is 10% by weight or less.
(I) The proportion of hydrous crumbs that pass through a 9.5 mm mesh JIS sieve and do not pass through a 6.7 mm JIS sieve is 30% by weight or less.
(C) The proportion of hydrous crumb that passes through a JIS sieve with an opening of 6.7 mm and does not pass through a JIS sieve with a mesh size of 710 μm is 20% by weight or more.
(E) The proportion of hydrous crumbs that pass through the JIS sieve with an opening of 710 μm and do not pass through the JIS sieve of 425 μm is 30% by weight or less, and (e) the proportion of hydrous crumbs that pass through the JIS sieve with an opening of 425 μm is 10 weight. %Less than.

When the proportion of the produced hydrous crumb that does not pass through the JIS sieve having an opening of 9.5 mm is 10% by weight or less, preferably 5% by weight or less, and more preferably 1% by weight or less, the emulsifier. It is suitable because it can significantly improve the cleaning efficiency of the coagulant and coagulant.

The proportion of the hydrous crumb that passed through the 9.5 mm mesh sieve and not the 6.7 mm JIS sieve of the produced hydrous crumb was 30% by weight or less, preferably 20% by weight or less, more preferably. When it is 5% by weight or less, the cleaning efficiency of the emulsifier or coagulant can be remarkably improved, which is preferable.

The proportion of the hydrous crumb that passed through the 6.7 mm mesh sieve and not the 710 μm JIS sieve of the produced hydrous crumb was 20% by weight or more, preferably 40% by weight or more, more preferably 70% by weight. % Or more, most preferably 80% by weight or more, the cleaning efficiency of the emulsifier or coagulant can be remarkably improved, which is preferable.

The proportion of the hydrous crumb that passed through the JIS sieve with an opening of 710 μm and did not pass through the JIS sieve of 425 μm was 30% by weight or less, preferably 20% by weight or less, and more preferably 15% by weight or less. When it is, the cleaning efficiency of the emulsifier and the coagulant is remarkably improved, and the productivity is also high, which is suitable.

When the proportion of the hydrous crumb that passes through the JIS sieve with an opening of 425 μm is 10% by weight or less, preferably 5% by weight or less, and more preferably 1% by weight or less, the emulsifier or coagulation The cleaning efficiency of the agent is remarkably improved, and the productivity is high, which is suitable.

In the present invention, the proportion of the hydrous crumb that passes through the JIS sieve having a (or) mesh size of 6.7 mm and does not pass through the JIS sieve having a mesh size of 4.75 mm is not particularly limited. However, when it is usually 40% by weight or less, preferably 10% by weight or less, and more preferably 5% by weight or less, the cleaning efficiency of the emulsifier or coagulant is improved and is preferable.

In the present invention, the proportion of the water-containing crumb that passes through the JIS sieve having a (ki) mesh size of 4.75 mm and does not pass through the JIS sieve having a mesh size of 710 μm is not particularly limited. , Usually 40% by weight or more, preferably 60% by weight or more, more preferably 80% by weight or more, the removal efficiency at the time of washing and dehydrating the emulsifier and coagulant is remarkably improved, which is preferable.

Further, in the present invention, the proportion of the water-containing crumb that passes through the JIS sieve having a (ku) mesh size of 3.35 mm and does not pass through the JIS sieve having a mesh size of 710 μm is not particularly limited. When washing and dehydrating the emulsifier and coagulant when it is usually 20% by weight or more, preferably 40% by weight or more, more preferably 50% by weight or more, particularly preferably 60% by weight or more, and most preferably 70% by weight or more. The removal efficiency of the sieving is remarkably improved, which is suitable.

(Washing process)
The cleaning step in the method for producing an acrylic rubber veil of the present invention is a step of cleaning the produced hydrous crumb with a large amount of water.

The cleaning method is not particularly limited and may follow a conventional method. For example, the produced hydrous crumb can be mixed with a large amount of warm water.

The amount of water used is not particularly limited, but the amount per washing with water is usually 50 parts by weight or more, preferably 50 to 15,000 parts by weight, based on 100 parts by weight of the monomer component. The amount of ash in the acrylic rubber can be effectively reduced, preferably in the range of 100 to 10,000 parts by weight, particularly preferably in the range of 150 to 5,000 parts by weight.

The temperature of the water to be washed with water is not particularly limited, but it is preferable to use warm water, and it is usually 40 ° C. or higher, preferably 40 to 100 ° C., more preferably 50 to 90 ° C., and most preferably 60 to 60 to. It is suitable because the cleaning efficiency can be remarkably increased at 80 ° C.

By setting the temperature of the washing water to the above lower limit or higher, the emulsifier and the coagulant are released from the hydrous crumb to further improve the washing efficiency.

The washing time is not particularly limited, but is usually in the range of 1 to 120 minutes, preferably 2 to 60 minutes, and more preferably 3 to 30 minutes.

The number of washings is not particularly limited, and is usually 1 to 10 times, preferably a plurality of times, and more preferably 2 to 3 times. From the viewpoint of reducing the residual amount of the coagulant in the finally obtained acrylic rubber, it is desirable that the number of washings with water is large, but the shape of the water-containing crumb and the diameter of the water-containing crumb should be specified and / or By setting the cleaning temperature within the above range, the number of cleanings can be significantly reduced.

(Dehydration process)
The dehydration step in the present invention is characterized in that the washed water-containing crumb is squeezed out from the water-containing crumb by using a dehydrator.

In the present invention, the water-containing crumb to be dehydrated is preferably one in which free water is separated by a drainer after washing. As the drainer, a known one can be used without particular limitation, and examples thereof include a wire mesh, a screen, an electric sieve, and the like, preferably a wire mesh and a screen. The water content of the water-containing crumb after draining, that is, the water content of the water-containing crumb put into the dehydration / drying step is not particularly limited, but is usually 50 to 80% by weight, preferably 50 to 70% by weight. More preferably, it is in the range of 50 to 60% by weight.

The dehydrator is not particularly limited and may follow a conventional method. Examples thereof include a centrifuge, a squeezer, and a screw type extruder. In particular, the screw type extruder has a high water content in a water-containing crumb. It is suitable because it can be lowered to. Acrylic rubber adheres to the wall surface and slits in a centrifuge, etc., and can only be dehydrated to a water content of about 45% by weight, and is forcibly squeezed out like a screw extruder. The mechanism is suitable.

The slit width of the dehydrator may be in accordance with a conventional method, and when it is usually in the range of 0.1 to 1 mm, preferably 0.2 to 0.6 mm, the efficiency and production of removing coagulants and emulsifiers from the hydrous crumbs. The properties are highly balanced and suitable.

The water content of the water-containing crumb after dehydration after squeezing out is not particularly limited, but is usually in the range of 1 to 50% by weight, preferably 10 to 40% by weight, and more preferably 15 to 35% by weight. By setting the water content after dehydration to be equal to or higher than the lower limit, the dehydration time can be shortened and deterioration of acrylic rubber can be suppressed, and by setting it to be lower than the upper limit, the amount of ash can be sufficiently reduced.

(Drying process)
The drying step in the method for producing an acrylic rubber veil of the present invention is a step of drying the dehydrated water-containing crumb to obtain a dried rubber having a water content of less than 1% by weight.

The method for drying the water-containing crumb may be according to a conventional method, and for example, it can be dried using a dryer such as a hot air dryer, a vacuum dryer, an expander dryer, a kneader type dryer, or a screw type extruder.

The shape of the dried rubber is not particularly limited, and examples thereof include a crumb shape, a powder shape, a rod shape, and a sheet shape. Among these, the sheet shape is particularly preferable.
The water content of the dried rubber is less than 1% by weight, preferably 0.8% by weight or less, and more preferably 0.6% by weight or less.

(Veiling process)
The bale step in the method for producing an acrylic rubber bale of the present invention is a step of bale the obtained dry rubber having a water content of less than 1% by weight.

The bale of the dried rubber may be made according to a conventional method. For example, the dried rubber can be put in a baler and compressed for production. The compression pressure is appropriately selected depending on the intended use, but is usually in the range of 0.1 to 15 MPa, preferably 0.5 to 10 MPa, and more preferably 1 to 5 MPa. The compression time is not particularly limited, but is usually in the range of 1 to 60 seconds, preferably 5 to 30 seconds, and more preferably 10 to 20 seconds.

In the present invention, it is also possible to prepare a sheet-shaped dry rubber and laminate it to form a veil. Veiling by laminating sheets is suitable because it is easy to manufacture, a bale with few bubbles (large specific gravity) can be formed, and storage stability is excellent.

(Dehydration / drying process and bale process using screw type extruder)
In the present invention, it is preferable to perform the dehydration step and the drying step by using a dehydration barrel having a dehydration slit, a drying barrel for drying under reduced pressure, and a screw type extruder provided with a die at the tip. After that, it is preferable to carry out the bale step, and the embodiment thereof will be shown below.

Draining step In the method for producing an acrylic rubber bale of the present invention, it is necessary to provide a draining step for separating free water from the water-containing crumb after washing with a drainer before shifting from the washing step to the dehydration / drying step. It is suitable for raising.

As the drainer, a known one can be used without particular limitation, and examples thereof include a wire mesh, a screen, an electric sieve, and the like, preferably a wire mesh and a screen.

The opening of the drainer is not particularly limited, but when it is usually in the range of 0.01 to 5 mm, preferably 0.1 to 1 mm, and more preferably 0.2 to 0.6 mm, the water content crumb loss is small. Moreover, draining can be done efficiently, which is suitable.

The water content of the water-containing crumb after draining, that is, the water content (rate) of the water-containing crumb added to the dehydration / drying / molding step is not particularly limited, but is usually 50 to 80% by weight, preferably 50 to 50 to 50% by weight. It is in the range of 70% by weight, more preferably 50 to 60% by weight.

The temperature of the water-containing crumb after draining, that is, the temperature of the water-containing crumb put into the dehydration / drying / molding step is not particularly limited, but is usually 40 ° C. or higher, preferably 40 to 95 ° C., more preferably 50 ° C. It is in the range of about 90 ° C., particularly preferably 55 to 85 ° C., and most preferably 60 to 80 ° C.

Dehydration / Drying of Dehydration Barrel The dehydration of the water-containing crumb is performed in a dehydration barrel having a dehydration slit provided in the screw type extruder. The opening of the dehydration slit may be appropriately selected according to the conditions of use, but when it is usually in the range of 0.1 to 1 mm, preferably 0.2 to 0.6 mm, the loss of the water-containing crumb is small. Moreover, dehydration of the hydrous crumb can be performed efficiently, which is suitable.

The number of dehydration barrels in the screw extruder is not particularly limited, but usually a plurality, preferably 2 to 10, more preferably 3 to 6, is used to dehydrate the adhesive acrylic rubber. It is suitable for efficient operation.

There are two ways to remove water from the water-containing crumb in the dehydration barrel: one that removes water from the dehydration slit in liquid form (drainage) and one that removes water in the form of steam (exhaust vapor). Exhaust steam is defined as dry and distinguished.

When using a screw type extruder equipped with a plurality of dehydration barrels, it is preferable to combine drainage and exhaust steam because drainage (dehydration) of the adhesive acrylic rubber and reduction of water content can be efficiently performed. Whether to use a drainage type dehydration barrel or a steam exhaust type dehydration barrel for each barrel of the screw type extruder equipped with three or more dehydration barrels may be appropriately selected according to the purpose of use, but acrylic usually produced. To reduce the amount of ash in the rubber, increase the number of drainage barrels. For example, if there are 3 dehydration barrels, select 2 drainage barrels, and if there are 4 dehydration barrels, select 3 drainage barrels. ..

The set temperature of the dehydration barrel is appropriately selected depending on the type of acrylic rubber, ash content, water content, operating conditions, etc., but is usually 60 to 150 ° C., preferably 70 to 140 ° C., more preferably 80 to 130 ° C. The range. The set temperature of the dehydration barrel that dehydrates in the drained state is usually 60 ° C. to 120 ° C., preferably 70 to 110 ° C., and more preferably 80 to 100 ° C. The set temperature of the dehydration barrel that dries in the exhausted steam state is usually in the range of 100 to 150 ° C., preferably 105 to 140 ° C., and more preferably 110 to 130 ° C.

The water content of the crumb after drainage type dehydration that squeezes water from the water content crumb, that is, after passing through the drainage type dehydration barrel is not particularly limited, but is usually 1 to 45% by weight, preferably 1 to 40% by weight. When it is more preferably 5 to 35% by weight, particularly preferably 10 to 35% by weight, the productivity and the distribution removal efficiency are highly balanced and preferable.

When dehydration of adhesive acrylic rubber is performed using a centrifuge or the like, acrylic rubber adheres to the dehydration slit portion and can hardly be dehydrated (water content is up to about 45 to 55% by weight), but in the present invention. By using a screw type extruder that has a dehydration slit and is forcibly squeezed with a screw, the water content can be reduced to this extent.

In the dehydration of the water-containing crumb when the drain type dehydration barrel and the exhaust steam type dehydration barrel are provided, the water content immediately after passing through the drain type dehydration barrel portion is usually 5 to 45% by weight, preferably 10 to 40% by weight, more preferably. The water content in the exhaust steam type dehydration barrel portion is usually 1 to 30% by weight, preferably 3 to 20% by weight, and more preferably 5 to 15% by weight.

By setting the water content after dehydration to be equal to or higher than the lower limit, the dehydration time can be shortened and deterioration of acrylic rubber can be suppressed, and by setting it to be lower than the upper limit, the amount of ash can be sufficiently reduced.

Drying of the dry barrel portion The hydrous crumb that has been dehydrated and dried in the dehydration barrel portion is further dried in the dry barrel portion under reduced pressure.

The degree of decompression of the drying barrel may be appropriately selected, but it is preferable that the hydrous crumb can be efficiently dried when it is usually 1 to 50 kPa, preferably 2 to 30 kPa, and more preferably 3 to 20 kPa.

The set temperature of the drying barrel may be appropriately selected, but when it is usually in the range of 100 to 250 ° C., preferably 110 to 200 ° C., more preferably 120 to 180 ° C., there is no discoloration or deterioration of the acrylic rubber. It is suitable because it can be dried efficiently and the amount of gel in which the methyl ethyl ketone is insoluble in acrylic rubber can be reduced.

The number of drying barrels in the screw extruder is not particularly limited, but is usually a plurality, preferably 2 to 10, and more preferably 3 to 8. When there are a plurality of dry barrels, the degree of decompression may be an approximate degree of decompression for all the dry barrels, or may be changed. When there are multiple drying barrels, the set temperature may be an approximate temperature for all the drying barrels or may be changed, but it is closer to the discharge part (closer to the die) than the temperature of the introduction part (closer to the dehydration barrel). It is preferable to raise the temperature of (1) because the drying efficiency can be increased.

The water content of the dried rubber after drying is usually less than 1% by weight, preferably 0.8% by weight or less, and more preferably 0.6% by weight or less. In the present invention, the phenolic anti-aging agent and acrylic rubber are melt-kneaded and extruded at this value (with almost all water removed), especially in a screw-type extruder, to achieve storage stability and heat resistance. Acrylic rubber bale with highly improved properties can be produced, which is suitable. In the present invention, the acrylic rubber is melt-kneaded in a state where most of the water is removed, so that the gel amount of the methyl ethyl ketone insoluble portion of the acrylic rubber veil can be reduced and the processability of the acrylic rubber veil can be remarkably improved, which is preferable. Is.

Acrylic rubber shape (die part)
The acrylic rubber dehydrated and dried by the screw portion of the dehydration barrel and the drying barrel is sent to the rectifying die portion without a screw. A breaker plate or wire mesh may or may not be provided between the screw portion and the die portion.

Acrylic rubber to be extruded can be obtained in various shapes such as granular, columnar, round bar, and sheet depending on the nozzle shape of the die. It is suitable because a dry rubber having a small amount of water and a large specific gravity and excellent storage stability can be obtained.

The resin pressure in the die portion is not particularly limited, but when it is usually in the range of 0.1 to 10 MPa, preferably 0.5 to 5 MPa, more preferably 1 to 3 MPa, air entrainment is small and the productivity is excellent. Suitable.

Screw type extruder and operating conditions The screw length (L) of the screw type extruder used may be appropriately selected according to the purpose of use, but is usually 3000 to 15000 mm, preferably 4000 to 10000 mm, and more preferably 4500. The range is ~ 8000 mm.

The screw diameter (D) of the screw type extruder used may be appropriately selected depending on the intended use, but is usually in the range of 50 to 250 mm, preferably 100 to 200 mm, and more preferably 120 to 160 mm.

The ratio (L / D) of the screw length (L) to the screw diameter (D) of the screw type extruder used is not particularly limited, but is usually 10 to 100, preferably 20 to 80, and more. When it is preferably in the range of 30 to 60, particularly preferably 40 to 50, the water content can be reduced to less than 1% by weight without causing a decrease in the molecular weight or burning of the dried rubber.

The rotation speed (N) of the screw type extruder used may be appropriately selected according to various conditions, but is usually 10 to 1000 rpm, preferably 50 to 750 rpm, more preferably 100 to 500 rpm, and most preferably 120. At ~ 300 rpm, the water content and gel amount of acrylic rubber can be efficiently reduced, which is preferable.

The extrusion amount (Q) of the screw type extruder used is not particularly limited, but is usually 100 to 1,500 kg / hr, preferably 300 to 1200 kg / hr, more preferably 400 to 1000 kg / hr, and most preferably 500. It is in the range of ~ 800 kg / hr.

The ratio (Q / N) of the extrusion amount (Q) to the rotation speed (N) of the screw type extruder used is not particularly limited, but is usually 2 to 10, preferably 3 to 8, more preferably. Is in the range of 4-6.

Dry rubber The shape of the dry rubber extruded from the screw type extruder is not particularly limited, and examples thereof include a crumb shape, a powder shape, a rod shape, a sheet shape, and the sheet shape is particularly preferable.

The temperature of the dry rubber extruded from the screw type extruder is not particularly limited, but is usually in the range of 100 to 200 ° C., preferably 110 to 180 ° C., and more preferably 120 to 160 ° C.

The water content of the dry rubber extruded from the screw type extruder is less than 1% by weight, preferably 0.8% by weight or less, and more preferably 0.6% by weight or less.

Bale step The sheet-shaped dry rubber extruded from the screw type extruder can be cut as needed and laminated to form a bale. Veiling by laminating sheet-shaped dry rubber is suitable because it is easy to manufacture, and a bale with few bubbles (large specific gravity) can be formed, and it has excellent storage stability. The following shows a mode in which the sheet-shaped dry rubber is extruded from the screw type extruder, and then the sheets are laminated and veiled.

The thickness of the sheet-shaped dry rubber extruded from the screw type extruder is not particularly limited, but is usually in the range of 1 to 40 mm, preferably 2 to 35 mm, more preferably 3 to 30 mm, and most preferably 5 to 25 mm. At some point productivity is particularly good and suitable. In particular, since the thermal conductivity of the sheet-shaped dry rubber is as low as 0.15 to 0.35 W / mK, the cooling rate is slow, and when cooling is performed efficiently, the thickness of the sheet-shaped dry rubber is usually 1 to 1. The range is 30 mm, preferably 2 to 25 mm, more preferably 3 to 15 mm, and particularly preferably 4 to 12 mm.

The width of the sheet-shaped dry rubber extruded from the screw type extruder is appropriately selected depending on the intended use, but is usually in the range of 300 to 1200 mm, preferably 400 to 1000 mm, and more preferably 500 to 800 mm.

The temperature of the sheet-shaped dry rubber extruded from the screw type extruder is not particularly limited, but is usually in the range of 100 to 200 ° C., preferably 110 to 180 ° C., and more preferably 120 to 160 ° C.

The complex viscosity ([η] 100 ° C.) of the sheet-shaped dry rubber extruded from the screw type extruder at 100 ° C. is not particularly limited, but is usually 1500 to 6000 Pa · s, preferably 2000 to 5000 Pa · s. , More preferably in the range of 2500 to 4000 Pa · s, most preferably 2500 to 3500 Pa · s, the extrudability and shape retention as a sheet are highly balanced and preferable. That is, when it is set to the lower limit or more, the extrudability can be improved, and when it is set to the upper limit or less, the shape of the sheet-shaped dried rubber can be suppressed from collapsing or breaking.

In the present invention, the sheet-shaped dry rubber extruded from the screw type extruder is suitable because it is laminated after cutting and veiled because the amount of air involved is small and the storage stability is excellent. The cutting of the sheet-shaped dry rubber is not particularly limited, but since the acrylic rubber of the acrylic rubber veil of the present invention has strong adhesiveness, the sheet-shaped dry rubber is used in order to continuously cut without entraining air. It is preferable to carry out after cooling.

The cutting temperature of the sheet-shaped dry rubber is not particularly limited, but when it is usually 60 ° C. or lower, preferably 55 ° C. or lower, more preferably 50 ° C. or lower, the cutability and productivity are highly balanced and preferable. Is.

The complex viscosity ([η] 60 ° C.) of the sheet-shaped dry rubber at 60 ° C. is not particularly limited, but is usually 15,000 Pa · s or less, preferably 2000 to 10,000 Pa · s, more preferably. When it is in the range of 2500 to 7000 Pa · s, most preferably 2700 to 5500 Pa · s, it is preferable because it can cut continuously without entraining air.

The ratio ([η] 100 ° C / [η] 60 ° C) of the sheet-shaped dried rubber to the complex viscosity ([η] 100 ° C) at 100 ° C and the complex viscosity ([η] 60 ° C) at 60 ° C is Although not particularly limited, air is usually in the range of 0.5 or more, preferably 0.5 to 0.98, more preferably 0.6 to 0.95, and most preferably 0.75 to 0.93. It is suitable because it has low entanglement and has a high balance between cutting and productivity.

The method for cooling the sheet-shaped dried rubber is not particularly limited and may be left at room temperature. However, since the heat conductivity of the sheet-shaped dried rubber is very small, 0.15 to 0.35 W / mK, it is blown or blown. Forced cooling such as an air cooling method under cooling, a water spraying method of spraying water, or a dipping method of immersing in water is preferable for increasing productivity, and an air cooling method of blowing air or cooling is particularly preferable.

In the air-cooled method of sheet-shaped dry rubber, for example, the sheet-shaped dry rubber can be extruded from a screw-type extruder onto a conveyor such as a belt conveyor, and can be conveyed and cooled while blowing cold air. The temperature of the cold air is not particularly limited, but is usually in the range of 0 to 25 ° C, preferably 5 to 25 ° C, and more preferably 10 to 20 ° C. The length to be cooled is not particularly limited, but is usually in the range of 5 to 500 m, preferably 10 to 200 m, and more preferably 20 to 100 m. The cooling rate of the sheet-shaped dry rubber is not particularly limited, but it is particularly easy to cut when it is usually 50 ° C./hr or more, more preferably 100 ° C./hr or more, and more preferably 150 ° C./hr or more. It is suitable.

The cutting length of the sheet-shaped dry rubber is not particularly limited and may be appropriately selected according to the size of the acrylic rubber bale to be manufactured, but is usually 100 to 800 mm, preferably 200 to 500 mm, more preferably 250 to 450 mm. Is the range of.

The sheet-shaped dry rubber after cutting is laminated and veiled. The laminating temperature of the sheet-shaped dry rubber is not particularly limited, but is preferably 30 ° C. or higher, preferably 35 ° C. or higher, more preferably 40 ° C. or higher, because air entrained during laminating can be released. The number of layers may be appropriately selected according to the size or weight of the acrylic rubber veil. In the acrylic rubber veil of the present invention, laminated sheet-shaped dry rubber is integrated by its own weight.

The acrylic rubber veil of the present invention thus obtained has excellent operability and storage stability as compared with crumb-shaped acrylic rubber, and the acrylic rubber veil can be used as it is or cut into a required amount and put into a mixer such as a vanbury or roll. Can be used.

<Rubber mixture>
The rubber mixture of the present invention is characterized in that the acrylic rubber veil is mixed with a filler and a cross-linking agent.

The filler is not particularly limited, and examples thereof include a reinforcing filler and a non-reinforcing filler, and a reinforcing filler is preferable.

Examples of the reinforcing filler include carbon black such as furnace black, acetylene black, thermal black, channel black, and graphite; silica such as wet silica, dry silica, and colloidal silica; and the like. Examples of the non-reinforcing filler include quartz powder, silica soil, zinc flower, basic magnesium carbonate, active calcium carbonate, magnesium silicate, aluminum silicate, titanium dioxide, talc, aluminum sulfate, calcium sulfate, barium sulfate and the like. be able to.

Each of these fillers can be used alone or in combination of two or more, and the blending amount thereof is appropriately selected within a range that does not impair the effect of the present invention, with respect to 100 parts by weight of the acrylic rubber veil. It is usually in the range of 1 to 200 parts by weight, preferably 10 to 150 parts by weight, and more preferably 20 to 100 parts by weight.

The cross-linking agent may be appropriately selected according to the type and use of the reactive group contained in the acrylic rubber constituting the acrylic rubber veil, but is not particularly limited as long as it can cross the acrylic rubber bale. , For example, polyvalent amine compounds such as diamine compounds, and carbonates thereof; sulfur compounds; sulfur conjugates; triazinethiol compounds; polyvalent epoxy compounds; ammonium organic carboxylates; organic peroxides; polyvalent carboxylic acids; Conventionally known cross-linking agents such as quaternary onium salt; imidazole compound; isocyanuric acid compound; organic peroxide; triazine compound; can be used. Among these, polyvalent amine compounds, ammonium carboxylates, metal dithiocarbamic acid salts and triazinethiol compounds are preferable, hexamethylenediamine carbamate, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, and benzoic acid. Ammonium acid, 2,4,6-trimercapto-1,3,5-triazine is particularly preferred.

When the acrylic rubber veil to be used is composed of a carboxyl group-containing acrylic rubber, it is preferable to use a polyvalent amine compound and a carbonate thereof as a cross-linking agent. Examples of the polyvalent amine compound include aliphatic polyvalent amine compounds such as hexamethylenediamine, hexamethylenediamine carbamate, and N, N'-dicinnamylidene-1,6-hexanediamine; 4,4'-methylenedianiline, p. -Phenylene diamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-(m-phenylenediisopropyridene) dianiline, 4,4'-(p-phenylenedi) Isopropyridene) dianiline, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 4,4'-diaminobenzanilide, 4,4'-bis (4-aminophenoxy) biphenyl, m-xyli Aromatic polyvalent amine compounds such as rangeamine, p-xylylenediamine, 1,3,5-benzenetriamine; and the like. Among these, hexamethylenediamine carbamate, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane and the like are preferable.

When the acrylic rubber veil to be used is composed of epoxy group-containing acrylic rubber, aliphatic polyvalent amine compounds such as hexamethylenediamine and hexamethylenediamine carbamate, and carbonates thereof; 4,4'-methylene as a cross-linking agent. Aromatic polyvalent amine compounds such as dianiline; ammonium carboxylic acid salts such as ammonium benzoate and ammonium adipate; metal dithiocarbamic acid salts such as zinc dimethyldithiocarbamate; polyvalent carboxylic acids such as tetradecanodic acid; cetyltrimethylammonium bromide Tertiary onium salts such as; imidazole compounds such as 2-methylimidazole; isocyanuric acid compounds such as ammonium isocyanurate; among these, ammonium carboxylate salt and metal dithiocarbamate salt are preferable, and ammonium benzoate is preferable. Is more preferable.

When the acrylic rubber veil to be used is composed of a halogen atom-containing acrylic rubber, it is preferable to use sulfur, a sulfur donor, or a triazine thiol compound as a cross-linking agent. Examples of the sulfur donor include dipentamethylene thiuram hexasulfide and triethyl thiuram disulfide. Examples of the triazine compound include 6-trimercapto-s-triazine, 2-anilino-4,6-dithiol-s-triazine, 1-dibutylamino-3,5-dimercaptotriazine, 2-dibutylamino-4, 6-Dithiol-s-Triazine, 1-Phenylamino-3,5-Dimercaptotriazine, 2,4,6-Trimercapto-1,3,5-Triazine, 1-Hexylamino-3,5-Dimercaptotriazine Among these, 2,4,6-trimercapto-1,3,5-triazine is preferable.

Each of these cross-linking agents can be used alone or in combination of two or more, and the blending amount thereof is usually 0.001 to 20 parts by weight, preferably 0.1 parts by weight, based on 100 parts by weight of the acrylic rubber veil. It is ~ 10 parts by weight, more preferably 0.1 ~ 5 parts by weight. By setting the blending amount of the cross-linking agent within this range, it is possible to make the mechanical strength of the rubber cross-linked product excellent while making the rubber elasticity sufficient, which is preferable.

In the rubber mixture of the present invention, other rubber components other than the acrylic rubber veil can be used, if necessary.

Other rubber components used as needed are not particularly limited, for example, natural rubber, polybutadiene rubber, polyisoprene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, silicon rubber, fluororubber, olefin-based. Examples thereof include elastomers, styrene-based elastomers, vinyl chloride-based elastomers, polyester-based elastomers, polyamide-based elastomers, polyurethane-based elastomers, and polysiloxane-based elastomers. The shape of the other rubber components is not particularly limited, and may be, for example, a powder or granular material, a pellet, a crumb, a sheet, a veil, or the like.

These other rubber components can be used alone or in combination of two or more. The amount of these other rubber components used is appropriately selected within a range that does not impair the effects of the present invention.

The rubber mixture of the present invention may contain an antiaging agent, if necessary. The anti-aging agent is not particularly limited, but is 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butylphenol, butylhydroxyanisole, 2,6-di-t-butyl-. α-Dimethylamino-p-cresol, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, styrenated phenol, 2,2'-methylene-bis (6-α-methyl-) Benzyl-p-cresol), 4,4'-methylenebis (2,6-di-t-butylphenol), 2,2'-methylene-bis (4-methyl-6-t-butylphenol), 2,4-bis [(Octylthio) Methyl] -6-methylphenol, 2,2'-thiobis- (4-methyl-6-t-butylphenol), 4,4'-thiobis- (6-t-butyl-o-cresol), Other phenolic antioxidants such as 2,6-di-t-butyl-4- (4,6-bis (octylthio) -1,3,5-triazine-2-ylamino) phenol; tris (nonylphenyl) Phenolic acid ester anti-aging agents such as phosphite, diphenylisodecylphosphite, tetraphenyldipropylene glycol diphosphite; sulfur ester anti-aging agents such as dilauryl thiodipropionate; phenyl-α-naphthylamine, phenyl-β- Naftylamine, p- (p-toluenesulfonylamide) -diphenylamine, 4,4'-(α, α-dimethylbenzyl) diphenylamine, N, N-diphenyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p -Amine-based antioxidants such as phenylenediamine, butylaldehyde-aniline condensate; imidazole-based antioxidants such as 2-mercaptobenzimidazole; 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinolin, etc. Kinolin-based anti-aging agents; hydroquinone-based anti-aging agents such as 2,5-di- (t-amyl) hydroquinone; and the like. Among these, amine-based antiaging agents are particularly preferable. The anti-aging agent used here may be the same as or different from the anti-aging agent used in the emulsion polymerization step.

These anti-aging agents can be used alone or in combination of two or more, and the blending amount thereof is 0.01 to 15 parts by weight, preferably 0.% by weight, based on 100 parts by weight of the acrylic rubber veil. It is in the range of 1 to 10 parts by weight, more preferably 1 to 5 parts by weight.

The rubber mixture of the present invention contains the acrylic rubber veil of the present invention, a filler, a cross-linking agent and, if necessary, other rubber components and an anti-aging agent, and is usually used in the art as necessary. Other additives such as cross-linking aids, cross-linking accelerators, cross-linking retarders, silane coupling agents, plasticizers, processing aids, rubbers, pigments, colorants, antistatic agents, foaming agents, etc. are optionally blended. can. These other compounding agents can be used alone or in combination of two or more, and the compounding amount thereof is appropriately selected within a range that does not impair the effects of the present invention.

<Manufacturing method of rubber mixture>
Examples of the method for producing the rubber mixture of the present invention include a method of mixing the filler, the cross-linking agent and the other compounding agent which can be contained as needed in the acrylic rubber veil of the present invention. Any means used in the rubber processing field, such as an open roll, a Banbury mixer, and various kneaders, can be used. That is, using these mixers, the acrylic rubber veil can be mixed by directly mixing the filler, the cross-linking agent and the like, preferably by directly kneading.

In that case, the acrylic rubber bale may be used as it is or after being divided (cut or the like).

The mixing procedure of each component is not particularly limited, but for example, after sufficiently mixing the components that are difficult to react or decompose with heat, the reaction or decomposition occurs with a cross-linking agent that is a component that easily reacts or decomposes with heat. Two-step mixing is preferred, in which the mixture is mixed in a short time at no temperature. Specifically, it is preferable to mix the acrylic rubber veil and the filler in the first stage and then mix the cross-linking agent in the second stage. The other rubber component and the antiaging agent are usually mixed in the first stage, the cross-linking accelerator may be selected in the second stage, and the other compounding agent may be appropriately selected.

The Mooney viscosity (ML1 + 4,100 ° C.; compound Mooney) of the rubber mixture of the present invention thus obtained is not particularly limited, but is usually in the range of 10 to 150, preferably 20 to 100, and more preferably 25 to 80. Is.

<Rubber cross-linked product>
The rubber crosslinked product of the present invention is obtained by cross-linking the above rubber mixture.

The rubber crosslinked product of the present invention is formed by using the rubber mixture of the present invention with a molding machine corresponding to a desired shape, for example, an extruder, an injection molding machine, a compressor, a roll, or the like, and is crosslinked by heating. It can be produced by carrying out a reaction and fixing the shape as a rubber crosslinked product. In this case, cross-linking may be performed after molding in advance, or cross-linking may be performed at the same time as molding. The molding temperature is usually 10 to 200 ° C, preferably 25 to 150 ° C. The cross-linking temperature is usually 100 to 250 ° C., preferably 130 to 220 ° C., more preferably 150 to 200 ° C., and the cross-linking time is usually 0.1 minutes to 10 hours, preferably 1 minute to 5 hours. As the heating method, a method used for cross-linking rubber such as press heating, steam heating, oven heating, and hot air heating may be appropriately selected.

Depending on the shape, size, etc. of the rubber crosslinked product of the present invention, the rubber crosslinked product may be further heated for secondary cross-linking. The secondary cross-linking varies depending on the heating method, cross-linking temperature, shape and the like, but is preferably carried out for 1 to 48 hours. The heating method and heating temperature may be appropriately selected.

The rubber crosslinked product of the present invention is, for example, a sealing material such as an O-ring, packing, diaphragm, oil seal, shaft seal, bearing sheath, mechanical seal, well head seal, seal for electric / electronic equipment, and seal for air compression equipment. A unit cell equipped with a rocker cover gasket attached to the connecting portion between the cylinder block and the cylinder head, an oil pan gasket attached to the connecting portion between the oil pan and the cylinder head or the transmission case, a positive electrode, an electrolyte plate and a negative electrode. Various gaskets such as gaskets for fuel cell separators and gaskets for the top cover of hard disk drives mounted between a pair of sandwiched housings; cushioning material, vibration isolator; wire coating material; industrial belts; tubes and hoses; sheets It is preferably used as;

The rubber cross-linked product of the present invention is also used as an extruded molded product and a molded cross-linked product used in automobile applications, for example, fuel oil for fuel tanks such as fuel hoses, filler neck hoses, bent hoses, paper hoses, and oil hoses. It is suitably used for various hoses such as air hoses such as system hoses, turbo air hoses and mission control hoses, radiator hoses, heater hoses, brake hoses and air conditioner hoses.

<Device configuration used for manufacturing acrylic rubber veils>
Next, an apparatus configuration used for manufacturing an acrylic rubber veil according to an embodiment of the present invention will be described. FIG. 1 is a diagram schematically showing an example of an acrylic rubber manufacturing system having an apparatus configuration used for manufacturing an acrylic rubber veil according to an embodiment of the present invention. For the production of the acrylic rubber according to the present invention, for example, the acrylic rubber production system 1 shown in FIG. 1 can be used.

The acrylic rubber manufacturing system 1 shown in FIG. 1 is composed of an emulsion polymerization reactor (not shown), a coagulation device 3, a cleaning device 4, a drainer 43, a screw type extruder 5, a cooling device 6, and a bale device 7. ..

The emulsion polymerization reactor is configured to perform the treatment related to the emulsion polymerization step described above. Although not shown in FIG. 1, this emulsion polymerization reactor includes, for example, a polymerization reaction tank, a temperature control unit for controlling the reaction temperature, a motor, and a stirring device including a stirring blade. In the emulsion polymerization reactor, water and an emulsifier are mixed with a monomer component for forming acrylic rubber, emulsified while appropriately stirring with a stirrer, and emulsion polymerization is carried out in the presence of a polymerization catalyst to obtain an emulsion polymerization solution. Can be obtained. The addition of the phenol-based anti-aging agent or the phenol-based anti-aging agent-containing emulsion to the emulsion polymerization solution can be carried out as it is in the emulsion polymerization reactor. The emulsion polymerization reactor may be a batch type, a semi-batch type, or a continuous type, and may be any of a tank type reactor and a tube type reactor.

The coagulation device 3 shown in FIG. 1 is configured to perform the process related to the coagulation step described above. As schematically shown in FIG. 1, the coagulation device 3 includes, for example, a stirring tank 30, a heating unit 31 for heating the inside of the stirring tank 30, and a temperature control unit (not shown) for controlling the temperature inside the stirring tank 30. It has a stirring device 34 including a motor 32 and a stirring blade 33, and a drive control unit (not shown) that controls the rotation speed and rotation speed of the stirring blade 33. In the coagulation apparatus 3, a hydrous crumb can be generated by bringing the emulsion polymerization solution obtained by the emulsion polymerization reactor into contact with the coagulation solution as a coagulant and coagulating it.

In the coagulation apparatus 3, for example, the contact between the emulsion polymerization solution and the coagulation solution adopts a method of adding the emulsion polymerization solution to the agitating coagulation solution. That is, a hydrous crumb is generated by filling the stirring tank 30 of the coagulation device 3 with a coagulation liquid and adding and contacting the emulsion polymerization liquid with the coagulation liquid to coagulate the emulsion polymerization liquid.

The heating unit 31 of the coagulation device 3 is configured to heat the coagulation liquid filled in the stirring tank 30. Further, the temperature control unit of the coagulation device 3 controls the temperature inside the stirring tank 30 by controlling the heating operation by the heating unit 31 while monitoring the temperature inside the stirring tank 30 measured by the thermometer. It is configured. The temperature of the coagulating liquid in the stirring tank 30 is controlled by the temperature control unit so as to be usually in the range of 40 ° C. or higher, preferably 40 to 90 ° C., and more preferably 50 to 80 ° C.

The stirring device 34 of the solidifying device 3 is configured to stir the coagulating liquid filled in the stirring tank 30. Specifically, the stirring device 34 includes a motor 32 that generates rotational power and a stirring blade 33 that extends in a direction perpendicular to the rotation axis of the motor 32. The stirring blade 33 can flow the coagulating liquid by rotating around the rotation axis by the rotational power of the motor 32 in the coagulating liquid filled in the stirring tank 30. The shape and size of the stirring blade 33, the number of installations, and the like are not particularly limited.

The drive control unit of the coagulation device 3 is configured to control the rotational drive of the motor 32 of the stirring device 34 to set the rotation speed and the rotation speed of the stirring blade 33 of the stirring device 34 to predetermined values. The rotation of the stirring blade 33 is controlled by the drive control unit so that the stirring number of the coagulating liquid is, for example, usually 100 rpm or more, preferably 200 to 1000 rpm, more preferably 300 to 900 rpm, and particularly preferably 400 to 800 rpm. Will be done. The peripheral speed of the coagulating liquid is usually 0.5 m / s or more, preferably 1 m / s or more, more preferably 1.5 m / s or more, particularly preferably 2 m / s or more, and most preferably 2.5 m / s or more. The rotation of the stirring blade 33 is controlled by the drive control unit. Further, the drive control unit agitates the coagulant so that the upper limit of the peripheral speed is usually 50 m / s or less, preferably 30 m / s or less, more preferably 25 m / s or less, and most preferably 20 m / s or less. The rotation of the wing 33 is controlled.

The cleaning device 4 shown in FIG. 1 is configured to perform the processing related to the above-mentioned cleaning step. As schematically shown in FIG. 1, the cleaning device 4 includes, for example, a cleaning tank 40, a heating unit 41 that heats the inside of the cleaning tank 40, and a temperature control unit (not shown) that controls the temperature inside the cleaning tank 40. Have. In the cleaning device 4, the amount of ash in the finally obtained acrylic rubber veil can be effectively reduced by mixing the water-containing crumb generated by the coagulation device 3 with a large amount of water and cleaning.

The heating unit 41 of the cleaning device 4 is configured to heat the inside of the cleaning tank 40. Further, the temperature control unit of the cleaning device 4 controls the temperature inside the cleaning tank 40 by controlling the heating operation by the heating unit 41 while monitoring the temperature inside the cleaning tank 40 measured by the thermometer. It is configured. As described above, the temperature of the washing water in the washing tank 40 is usually controlled to be in the range of 40 ° C. or higher, preferably 40 to 100 ° C., more preferably 50 to 90 ° C., and most preferably 60 to 80 ° C. To wash.

The water-containing crumb washed by the washing device 4 is supplied to the screw type extruder 5 that performs the dehydration step and the drying step. At this time, it is preferable that the water-containing crumb after cleaning is supplied to the screw type extruder 5 through a drainer 43 capable of separating free water. For the drainer 43, for example, a wire mesh, a screen, an electric sieve, or the like can be used.

Further, when the water-containing crumb after cleaning is supplied to the screw type extruder 5, the temperature of the water-containing crumb is preferably 40 ° C. or higher, more preferably 60 ° C. or higher. For example, by setting the temperature of the water used for washing in the washing device 4 to 60 ° C. or higher (for example, 70 ° C.), the temperature of the water-containing crumb when supplied to the screw type extruder 5 is maintained at 60 ° C. or higher. The temperature of the hydrous crumb may be 40 ° C. or higher, preferably 60 ° C. or higher when it is transferred from the cleaning device 4 to the screw type extruder 5. As a result, the dehydration step and the drying step, which are the subsequent steps, can be effectively performed, and the water content of the finally obtained dried rubber can be significantly reduced.

The screw type extruder 5 shown in FIG. 1 is configured to perform the processes related to the above-mentioned dehydration step and drying step. Although the screw type extruder 5 is shown as a suitable example in FIG. 1, a centrifuge, a squeezer, or the like may be used as the dehydrator for performing the treatment related to the dehydration step, and the treatment related to the drying step may be performed. A hot air dryer, a vacuum dryer, an expander dryer, a kneader type dryer, or the like may be used as the dryer to be performed.

The screw type extruder 5 is configured to form the dried rubber obtained through the dehydration step and the drying step into a predetermined shape and discharge the rubber. Specifically, the screw type extruder 5 has a dehydration barrel portion 53 having a function as a dehydrator for dehydrating the hydrous crumb washed by the cleaning device 4, and a drying machine having a function as a dryer for drying the hydrous crumb. A barrel portion 54 is provided, and a die 59 having a molding function for forming a water-containing crumb is provided on the downstream side of the screw type extruder 5.

Hereinafter, the configuration of the screw type extruder 5 will be described with reference to FIG. FIG. 2 shows a configuration of a specific example suitable for the screw type extruder 5 shown in FIG. With this screw type extruder 5, the above-mentioned dehydration / drying step can be suitably performed.

The screw type extruder 5 shown in FIG. 2 is a twin-screw type extruder / dryer provided with a pair of screws (not shown) in the barrel unit 51. The screw type extruder 5 has a drive unit 50 that rotationally drives a pair of screws in the barrel unit 51. The drive unit 50 is attached to the upstream end (left end in FIG. 2) of the barrel unit 51. Further, the screw type extruder 5 has a die 59 at the downstream end (right end in FIG. 2) of the barrel unit 51.

The barrel unit 51 has a supply barrel portion 52, a dehydration barrel portion 53, and a dry barrel portion 54 from the upstream side to the downstream side (from the left side to the right side in FIG. 2).

The supply barrel portion 52 is composed of two supply barrels, that is, a first supply barrel 52a and a second supply barrel 52b.

Further, the dehydration barrel portion 53 is composed of three dehydration barrels, that is, a first dehydration barrel 53a, a second dehydration barrel 53b, and a third dehydration barrel 53c.

Further, the drying barrel portion 54 includes eight drying barrels, that is, a first drying barrel 54a, a second drying barrel 54b, a third drying barrel 54c, a fourth drying barrel 54d, and a fifth drying barrel 54e. , A sixth dry barrel 54f, a seventh dry barrel 54g, and an eighth dry barrel 54h.

As described above, the barrel unit 51 is configured by connecting the 13 divided barrels 52a to 52b, 53a to 53c, 54a to 54h from the upstream side to the downstream side.

Further, the screw type extruder 5 individually heats the barrels 52a to 52b, 53a to 53c, 54a to 54h, and determines the water content crumbs in the barrels 52a to 52b, 53a to 53c, 54a to 54h, respectively. It has a heating means (not shown) for heating to a temperature. The heating means includes a number corresponding to each barrel 52a to 52b, 53a to 53c, 54a to 54h. As such a heating means, for example, a configuration is adopted in which high temperature steam is supplied from the steam supply means to the steam distribution jackets formed in the barrels 52a to 52b, 53a to 53c, 54a to 54h. It is not limited to this. Further, the screw type extruder 5 has a temperature control means (not shown) that controls a set temperature of each heating means corresponding to each barrel 52a to 52b, 53a to 53c, 54a to 54h.

The number of supply barrels, dehydration barrels, and drying barrels that constitute each barrel portion 52, 53, 54 in the barrel unit 51 is not limited to the mode shown in FIG. 2, and the acrylic rubber to be dried is used. The number can be set according to the water content of the water-containing crumb.

For example, the number of supply barrels installed in the supply barrel portion 52 is, for example, 1 to 3. Further, the number of dehydration barrels installed in the dehydration barrel portion 53 is preferably, for example, 2 to 10, and more preferably 3 to 6, because dehydration of the water-containing crumb of the adhesive acrylic rubber can be efficiently performed. Further, the number of drying barrels installed in the drying barrel portion 54 is preferably, for example, 2 to 10, and more preferably 3 to 8.

The pair of screws in the barrel unit 51 are rotationally driven by a driving means such as a motor housed in the driving unit 50. The pair of screws extend from the upstream side to the downstream side in the barrel unit 51, and by being rotationally driven, the water-containing crumbs supplied to the supply barrel portion 52 can be conveyed to the downstream side while being mixed. It has become like. The pair of screws is preferably a biaxial meshing type in which the peaks and valleys are meshed with each other, whereby the dehydration efficiency and the drying efficiency of the hydrous crumb can be improved.

Further, the rotation direction of the pair of screws may be the same direction or different directions, but from the viewpoint of self-cleaning performance, a type that rotates in the same direction is preferable. The screw shape of the pair of screws is not particularly limited as long as it is a shape required for each barrel portion 52, 53, 54, and is not particularly limited.

The supply barrel portion 52 is a region for supplying the water-containing crumb into the barrel unit 51. The first supply barrel 52a of the supply barrel portion 52 has a feed port 55 for supplying a water-containing crumb in the barrel unit 51.

The dehydration barrel portion 53 is a region for separating and discharging a liquid (serum water) containing a coagulant or the like from the hydrous crumb.

The first to third dehydration barrels 53a to 53c constituting the dehydration barrel portion 53 have dehydration slits 56a, 56b, and 56c for discharging the water content of the hydrous crumb to the outside, respectively. A plurality of the dehydration slits 56a, 56b, 56c are formed in the dehydration barrels 53a to 53c, respectively.

The slit widths, that is, the openings of the dehydration slits 56a, 56b, and 56c may be appropriately selected according to the conditions of use, and are usually 0.01 to 5 mm. From the viewpoint of efficient dehydration, it is preferably 0.1 to 1 mm, and more preferably 0.2 to 0.6 mm.

There are two ways to remove water from the water-containing crumbs in each of the dehydration barrels 53a to 53c of the dehydration barrel portion 53: a liquid removal from the dehydration slits 56a, 56b, 56c, and a vapor removal. .. In the dehydration barrel portion 53 of the present embodiment, the case where water is removed in liquid form is defined as wastewater, and the case where water is removed in vapor form is defined as exhaust steam to distinguish them.

The dehydration barrel portion 53 is suitable because the water content of the adhesive acrylic rubber can be efficiently reduced by combining drainage and exhaust steam. In the dehydration barrel portion 53, which of the first to third dehydration barrels 53a to 53c is used for drainage or exhaust steam may be appropriately set according to the purpose of use, but is usually manufactured. When reducing the amount of ash in the acrylic rubber, it is advisable to increase the number of dehydration barrels for draining water. In that case, for example, as shown in FIG. 2, drainage is performed in the first and second dehydration barrels 53a and 53b on the upstream side, and steam is discharged in the third dehydration barrel 53c on the downstream side. Further, for example, when the dehydration barrel portion 53 has four dehydration barrels, it is conceivable that, for example, drainage is performed by three dehydration barrels on the upstream side and steam is exhausted by one dehydration barrel on the downstream side. On the other hand, when reducing the water content, it is preferable to increase the number of dehydration barrels for exhausting steam.

As described in the above-mentioned dehydration / drying step, the set temperature of the dehydration barrel portion 53 is usually in the range of 60 to 150 ° C., preferably 70 to 140 ° C., more preferably 80 to 130 ° C., and is dehydrated in the drained state. The set temperature of the dehydration barrel to be dehydrated is usually 60 ° C. to 120 ° C., preferably 70 to 110 ° C., more preferably 80 to 100 ° C., and the set temperature of the dehydration barrel to be dehydrated in the exhausted steam state is usually 100 to 150 ° C. The temperature is preferably in the range of 105 to 140 ° C, more preferably 110 to 130 ° C.

The drying barrel portion 54 is a region for drying the hydrous crumb after dehydration under reduced pressure. Of the first to eighth dry barrels 54a to 54h constituting the dry barrel portion 54, the second dry barrel 54b, the fourth dry barrel 54d, the sixth dry barrel 54f, and the eighth dry barrel 54h are It has vent ports 58a, 58b, 58c, and 58d for degassing, respectively. Vent pipes (not shown) are connected to the vent ports 58a, 58b, 58c, and 58d, respectively.

Vacuum pumps (not shown) are connected to the ends of the vent pipes, and the operation of these vacuum pumps reduces the pressure inside the drying barrel portion 54 to a predetermined pressure. The screw type extruder 5 has a pressure control means (not shown) that controls the operation of these vacuum pumps to control the degree of decompression in the drying barrel portion 54.

The degree of decompression in the dry barrel portion 54 may be appropriately selected, but as described above, it is usually set to 1 to 50 kPa, preferably 2 to 30 kPa, and more preferably 3 to 20 kPa.

The set temperature in the drying barrel portion 54 may be appropriately selected, but as described above, it is usually set to 100 to 250 ° C, preferably 110 to 200 ° C, and more preferably 120 to 180 ° C.

In each of the dry barrels 54a to 54h constituting the dry barrel portion 54, the set temperatures in all the dry barrels 54a to 54h may be approximated or different, but on the upstream side (dehydrated barrel portion). It is preferable to set the temperature on the downstream side (die 59 side) to a higher temperature than the temperature on the downstream side (53 side) because the drying efficiency is improved.

The die 59 is a mold arranged at the downstream end of the barrel unit 51, and has a discharge port having a predetermined nozzle shape. The acrylic rubber dried by the drying barrel portion 54 is extruded into a shape corresponding to a predetermined nozzle shape by passing through the discharge port of the die 59. The acrylic rubber passing through the die 59 is formed into various shapes such as granular, columnar, round bar, and sheet depending on the nozzle shape of the die 59. For example, by making the discharge port of the die 59 substantially rectangular, the acrylic rubber can be extruded into a sheet shape. A breaker plate or wire mesh may or may not be provided between the screw and the die 59.

According to the screw type extruder 5 according to the present embodiment, the water-containing crumb of the raw material acrylic rubber is extruded into a sheet-shaped dry rubber as follows.

The water-containing crumb of acrylic rubber obtained through the cleaning step is supplied from the feed port 55 to the supply barrel portion 52. The water-containing crumb supplied to the supply barrel portion 52 is sent from the supply barrel portion 52 to the dehydration barrel portion 53 by the rotation of the pair of screws in the barrel unit 51. In the dehydration barrel portion 53, as described above, the water contained in the water-containing crumb is drained and exhausted from the dehydration slits 56a, 56b, 56c provided in the first to third dehydration barrels 53a to 53c, respectively. , The hydrous crumb is dehydrated.

The water-containing crumb dehydrated by the dehydration barrel portion 53 is sent to the dry barrel portion 54 by rotation of a pair of screws in the barrel unit 51. The hydrous crumb sent to the dry barrel portion 54 is plastically mixed to form a melt, which generates heat and is carried to the downstream side while raising the temperature. Then, the water contained in the melt of the acrylic rubber is vaporized, and the water (steam) is discharged to the outside through vent pipes (not shown) connected to the vent ports 58a, 58b, 58c, and 58d, respectively.

By passing through the dry barrel portion 54 as described above, the hydrous crumb is dried and becomes a melt of acrylic rubber, and the acrylic rubber is supplied to the die 59 by the rotation of a pair of screws in the barrel unit 51 to form a sheet. It is extruded from the die 59 as a dry rubber of.

Here, an example of the operating conditions of the screw type extruder 5 according to the present embodiment will be given.

The rotation speed (N) of the pair of screws in the barrel unit 51 may be appropriately selected according to various conditions, and is usually 10 to 1000 rpm, and the water content and gel amount of the acrylic rubber veil can be efficiently reduced. From the point of view, it is preferably 50 to 750 rpm, more preferably 100 to 500 rpm, and most preferably 120 to 300 rpm.

The extrusion amount (Q) of acrylic rubber is not particularly limited, but is usually 100 to 1500 kg / hr, preferably 300 to 1200 kg / hr, more preferably 400 to 1000 kg / hr, and 500 to 800 kg / hr. hr is most preferred.

The ratio (Q / N) of the extrusion amount (Q) of the acrylic rubber to the rotation speed (N) of the screw is not particularly limited, but is usually 1 to 20, preferably 2 to 10, and more preferably. It is 3 to 8, and 4 to 6 is particularly preferable.

The cooling device 6 shown in FIG. 1 is configured to cool the dried rubber obtained through the dehydration step by the dehydrator and the drying step by the dryer. As the cooling method by the cooling device 6, various methods including an air cooling method by blowing air or cooling, a water spraying method of spraying water, a dipping method of immersing in water, and the like can be adopted. Further, the dried rubber may be cooled by leaving it at room temperature.

As described above, the dried rubber discharged from the screw type extruder 5 is extruded into various shapes such as granular, columnar, round bar, and sheet according to the nozzle shape of the die 59. Hereinafter, as an example of the cooling device 6, the transport type cooling device 60 for cooling the sheet-shaped dry rubber 10 formed into a sheet shape will be described with reference to FIG.

FIG. 3 shows the configuration of a transport type cooling device 60 suitable as the cooling device 6 shown in FIG. The transport type cooling device 60 shown in FIG. 3 is configured to cool by an air cooling method while transporting the sheet-shaped dry rubber 10 discharged from the discharge port of the die 59 of the screw type extruder 5. By using this transfer type cooling device 60, the sheet-shaped dry rubber discharged from the screw type extruder 5 can be suitably cooled.

The transport type cooling device 60 shown in FIG. 3 is used, for example, directly connected to the die 59 of the screw type extruder 5 shown in FIG. 2 or installed in the vicinity of the die 59.

The transport type cooling device 60 blows cold air to the conveyor 61 that conveys the sheet-shaped dry rubber 10 discharged from the die 59 of the screw type extruder 5 in the direction of arrow A in FIG. 3 and the sheet-shaped dry rubber 10 on the conveyor 61. It has a cooling means 65 for spraying.

The conveyor 61 has rollers 62 and 63, and a conveyor belt 64 that is wound around the rollers 62 and 63 and on which the sheet-shaped dry rubber 10 is placed. The conveyor 61 is configured to continuously convey the sheet-shaped dry rubber 10 discharged from the die 59 of the screw type extruder 5 to the downstream side (right side in FIG. 3) on the conveyor belt 64.

The cooling means 65 is not particularly limited, but has, for example, a structure capable of blowing the cooling air sent from the cooling air generating means (not shown) onto the surface of the sheet-shaped dry rubber 10 on the conveyor belt 64. And so on.

The length L1 of the conveyor 61 and the cooling means 65 of the transport type cooling device 60 (the length of the portion where the cooling air can be blown) is not particularly limited, but is, for example, 10 to 100 m, preferably 20 to 50 m. .. The transport speed of the sheet-shaped dry rubber 10 in the transport-type cooling device 60 is the length L1 of the conveyor 61 and the cooling means 65, the discharge speed of the sheet-shaped dry rubber 10 discharged from the die 59 of the screw type extruder 5. It may be appropriately adjusted according to the target cooling rate, cooling time, etc., but is, for example, 10 to 100 m / hr, more preferably 15 to 70 m / hr.

According to the transport type cooling device 60 shown in FIG. 3, the sheet-shaped dry rubber 10 discharged from the die 59 of the screw type extruder 5 is conveyed by the conveyor 61, and the sheet-shaped dry rubber 10 is transported from the cooling means 65 to the sheet-shaped dry rubber 10. The sheet-shaped dry rubber 10 is cooled by blowing cooling air.

The transport type cooling device 60 is not particularly limited to a configuration including one conveyor 61 and one cooling means 65 as shown in FIG. 3, and two or more conveyors 61 and two or more corresponding conveyors 61. It may be configured to include the cooling means 65 of the above. In that case, the total length of each of the two or more conveyors 61 and the cooling means 65 may be within the above range.

The bale-forming device 7 shown in FIG. 1 is configured to extrude from a screw-type extruder 5 and further process a dry rubber cooled by the cooling device 6 to produce a bale which is a block. As described above, the screw type extruder 5 can extrude the dried rubber into various shapes such as granular, columnar, round bar, and sheet, and the bale device 7 has various shapes as described above. It is configured to veil dry rubber molded into a shape. The weight and shape of the acrylic rubber bale produced by the bale-forming device 7 are not particularly limited, but for example, an acrylic rubber bale having a substantially rectangular cuboid shape of about 20 kg is produced.

The bale-forming device 7 may include, for example, a baler, and may produce an acrylic rubber bale by compressing the cooled dry rubber with the baler.

Further, when the sheet-shaped dry rubber 10 is manufactured by the screw type extruder 5, an acrylic rubber veil in which the sheet-shaped dry rubber 10 is laminated may be manufactured. For example, the bale-forming device 7 arranged on the downstream side of the transport-type cooling device 60 shown in FIG. 3 may be provided with a cutting mechanism for cutting the sheet-shaped dry rubber 10. Specifically, the cutting mechanism of the bale device 7 continuously cuts the cooled sheet-shaped dry rubber 10 at predetermined intervals and processes it into a cut sheet-shaped dry rubber 16 having a predetermined size. It is configured as follows. By laminating a plurality of cut sheet-shaped dry rubbers 16 cut to a predetermined size by a cutting mechanism, an acrylic rubber veil in which the cut-sheet-shaped dry rubbers 16 are laminated can be manufactured.

When producing an acrylic rubber veil on which the cut sheet-shaped dry rubber 16 is laminated, it is preferable to laminate the cut sheet-shaped dry rubber 16 at 40 ° C. or higher, for example. By laminating the cut sheet-shaped dry rubber 16 at 40 ° C. or higher, good air release is realized by further cooling and compression by its own weight.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. Unless otherwise specified, "parts", "%" and "ratio" in each example are based on weight.

Various physical properties were evaluated according to the following methods.

[Monomer composition]
Regarding the monomer composition in acrylic rubber, the monomer composition of each monomer unit in acrylic rubber was confirmed by H-NMR, and the activity of reactive groups remained in acrylic rubber and each reaction thereof. The sex group content was confirmed by the following test method.
The content ratio of each monomer unit in the acrylic rubber was calculated from the amount used in the polymerization reaction of each monomer and the polymerization conversion rate. Specifically, the polymerization reaction was an emulsion polymerization reaction, and the polymerization conversion rate was approximately 100% in which none of the unreacted monomers could be confirmed. It was the same as the amount used by the body.

[Reactive group content]
The content of the reactive group in the acrylic rubber veil was measured by the following method.
(1) The amount of carboxyl groups was calculated by dissolving an acrylic rubber veil in acetone and performing potentiometric titration with a potassium hydroxide solution.
(2) The amount of epoxy group was calculated by dissolving acrylic rubber veil in methyl ethyl ketone, adding a specified amount of hydrochloric acid to react with the epoxy group, and titrating the remaining amount of hydrochloric acid with potassium hydroxide.
(3) The amount of chlorine was calculated by completely burning an acrylic rubber veil in a combustion flask, absorbing the generated chlorine in water, and titrating with silver nitrate.

[Anti-aging agent content]
The anti-aging agent content (%) in the acrylic rubber veil was calculated by dissolving the acrylic rubber veil in tetrahydrofuran and performing gel permeation chromatography (GPC) measurement based on the calibration curve of the same anti-aging agent.

[Ash content]
The amount of ash (%) contained in the acrylic rubber veil was measured according to the JIS K6228 A method.

[Amount of ash component]
The amount of each component (ppm) in the acrylic rubber veil ash content was measured by XRF using ZSX Primus (manufactured by Rigaku) by pressing the collected ash content onto a Φ20 mm titration filter paper due to the difference in the above ash content measurement.

[Gel amount]
The gel amount (%) of the acrylic rubber veil was the amount of the insoluble matter in methyl ethyl ketone, and was determined by the following method.

About 0.2 g of acrylic rubber veil is weighed (Xg), immersed in 100 ml methyl ethyl ketone, left at room temperature for 24 hours, and then dissolved in a filtrate obtained by filtering out the insoluble matter in methyl ethyl ketone using an 80 mesh wire mesh, that is, methyl ethyl ketone. The dry solid content (Yg) obtained by evaporating and solidifying the filtrate in which only the rubber component was dissolved was weighed and calculated by the following formula.

Gel amount (%) = 100 × (XY) / X

[specific gravity]
The specific gravity of the acrylic rubber veil was measured according to the method A of JIS K6268 crosslinked rubber-density measurement.

[Glass transition temperature (Tg)]
The glass transition temperature (Tg) of acrylic rubber was measured using a differential scanning calorimeter (DSC, product name "X-DSC7000", manufactured by Hitachi High-Tech Science Co., Ltd.).

[PH]
The pH of the acrylic rubber veil was measured with a pH electrode after confirming that 6 g (± 0.05 g) of the acrylic rubber veil was dissolved in 100 g of tetrahydrofuran, and 2.0 ml of distilled water was added to completely dissolve the acrylic rubber veil.

[Water content]
The water content (%) of the acrylic rubber veil was measured according to the JIS K6238-1: Oven A (volatile content measurement) method.

[Molecular weight and molecular weight distribution]
The weight average molecular weight (Mw) and molecular weight distribution (Mz / Mw) of acrylic rubber are prepared by adding a solution of lithium chloride at 0.05 mol / L and 37% concentrated hydrochloric acid at 0.01% concentration to dimethylformamide as a solvent. It is an absolute molecular weight and an absolute molecular weight distribution measured by the GPC-MALS method used. Specifically, a multi-angle laser light scattering photometric meter (MALS) and a differential refractometer (RI) are incorporated into a GPC (Gel Permeation Chromatography) device, and the light scattering intensity and refraction of the molecular chain solution size-sorted by the GPC device are incorporated. The molecular weight of the solute and its content were sequentially calculated and obtained by measuring the rate difference with the elution time. The measurement conditions and measurement method by the GPC device are as follows.
Column: 2 TSKgel α-M (φ7.8 mm x 30 cm, manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Flow velocity: 0.8 ml / mm
Sample preparation: 5 ml of solvent was added to 10 mg of sample, and the mixture was gently stirred at room temperature (dissolution was visually observed). Then, filtration was performed using a 0.5 μm filter.

[Complex viscosity]
The complex viscosity η of the acrylic rubber bale is subjected to temperature dispersion (40 to 120 ° C.) at a strain of 473% and 1 Hz using a dynamic viscous elasticity measuring device "Rubber Process Analyzer RPA-2000" (manufactured by Alpha Technology Co., Ltd.). The measurement was performed to determine the complex viscosity η at each temperature. Here, among the above-mentioned dynamic viscoelasticities, the dynamic viscoelasticity at 60 ° C. is defined as the complex viscoelasticity η (60 ° C.), and the dynamic viscoelasticity at 100 ° C. is defined as the complex viscoelasticity η (100 ° C.). The values of ° C.) / η (60 ° C.) and η (60 ° C.) / η (100 ° C.) were calculated.

[Storage stability evaluation]
For the storage stability of the rubber sample, the rubber mixture of the rubber sample was put into a constant temperature and humidity chamber of 45 ° C. × 80% RH for 7 days, and the rubber sample before and after the test was used as the rubber mixture in a rubber vulcanization tester (moving dialeometer MDR; Perform a cross-linking test at 180 ° C. for 10 minutes using (manufactured by Alpha Technology) to calculate the rate of change in cross-linking density, which is the difference (MH-ML) between the maximum torque (MH) and the minimum torque (ML), and compare them. Example 1 was evaluated with an index of 100 (the smaller the index, the better the storage stability).

[Evaluation of workability]
Regarding the processability of the rubber sample, the rubber sample is put into a Banbury mixer heated to 50 ° C., kneaded for 1 minute, and then the compounding agent A containing the rubber mixture shown in Table 2 is added to obtain the rubber mixture in the first stage. The time required for integration to show the maximum torque value, that is, BIT (Black Incorporation Time) was measured and evaluated with an index of Comparative Example 1 as 100 (the smaller the index, the better the workability).

[Water resistance evaluation]
The water resistance of the rubber sample is determined by immersing the crosslinked product of the rubber sample in distilled water at a temperature of 85 ° C. for 100 hours in accordance with JIS K6258, performing a dipping test, and calculating the volume change rate before and after dipping according to the following formula. It was evaluated by an index with 1 as 100 (the smaller the index, the better the water resistance).

Volume change rate before and after immersion (%) = ((volume of test piece after immersion-volume of test piece before immersion) / volume of test piece before immersion) × 100

[Evaluation of normal physical properties]
The normal physical characteristics of the rubber sample were evaluated according to the following criteria by measuring the breaking strength, 100% tensile stress and breaking elongation of the crosslinked rubber sample of the rubber sample according to JIS K6251.
(1) The breaking strength was evaluated as ⊚ when it was 10 MPa or more and × when it was less than 10 MPa.
(2) For 100% tensile stress, 5 MPa or more was evaluated as ⊚, and less than 5 MPa was evaluated as x.
(3) The elongation at break was evaluated as ⊚ for 150% or more and x for less than 150%.

[Adjustment of emulsion containing anti-aging agent]
For the anti-aging agent-containing emulsion to be added to the emulsion after emulsion polymerization, a predetermined temperature and a predetermined amount of water are charged into an adjustment tank with a stirring blade, and a predetermined amount of emulsifier is added while stirring, based on the conditions shown in Table 1. To prepare an emulsifier solution, then add 1 part of an antioxidant to the emulsion, stir for 2 hours, measure the pH, and if the pH is not in the range of 3 to 6, use sulfuric acid or sodium hydroxide within the range. It was adjusted and manufactured so that it would fit in. The entire amount of the prepared anti-aging agent-containing emulsion was added to the emulsion polymerization solution after emulsion polymerization.

[Example 1]
In a mixing container equipped with a homomixer, 46 parts of pure water, 74.5 parts of ethyl acrylate, 17 parts of n-butyl acrylate, 7 parts of methoxyethyl acrylate, and 1.5 parts of mono-n-butyl fumarate, and 1.8 parts of octyloxydioxyethylene phosphate sodium salt was charged as an emulsifier and stirred to obtain a monomeric emulsion.

Next, 170 parts of pure water and 3 parts of the monomer emulsion obtained above were put into a polymerization reaction tank equipped with a thermometer and a stirrer, and cooled to 12 ° C. under a nitrogen stream. Next, the remainder of the monomer emulsion, 0.00033 parts of ferrous sulfate, 0.264 parts of sodium ascorbate, and 0.22 parts of potassium persulfate were continuously added dropwise to the polymerization reaction tank over 3 hours. .. After that, the reaction was continued while the temperature in the polymerization reaction was kept at 23 ° C., it was confirmed that the polymerization conversion rate reached approximately 100%, and hydroquinone as a polymerization terminator was added to stop the polymerization reaction. Then, the anti-aging emulsion 1 of the anti-aging agent (IRG1076) shown in Table 1 prepared above as the anti-aging agent-containing emulsion was added to obtain an emulsion polymer solution to which the anti-aging agent was added.

In a coagulation tank equipped with a thermometer and a stirrer, the anti-aging agent is contained in a 2% magnesium sulfate aqueous solution (coagulant) heated to 80 ° C. and vigorously stirred (600 rpm: peripheral speed 3.1 m / s). The added emulsion polymerization solution was heated to 80 ° C. and continuously added to solidify the polymer and filtered off to obtain a hydrous crumb.

Next, 194 parts of warm water (70 ° C.) was added to the coagulation tank and stirred for 15 minutes, then the water was discharged, and 194 parts of warm water (70 ° C.) was added again and stirred for 15 minutes to wash the water-containing crumb. Was done. The washed hydrous crumb (moisture content crumb temperature 65 ° C.) was supplied to a screw type extruder, dehydrated and dried, and a sheet-shaped dry rubber having a width of 300 mm and a thickness of 10 mm was extruded. Next, the sheet-shaped dry rubber was cooled at a cooling rate of 200 ° C./hr using a transport-type cooling device directly connected to the screw type extruder.

The screw type extruder used in the first embodiment has one supply barrel, three dehydration barrels (first to third dehydration barrels), and five drying barrels (first to fifth drying barrels). It is configured. The first and second dehydration barrels drain water, and the third dehydration barrel drains steam. The operating conditions of the screw type extruder were as follows.

Moisture content:
Moisture content of the hydrous crumb after drainage in the second dehydration barrel: 20%
Moisture content of the hydrous crumb after steam exhaust in the third dehydration barrel: 10%
Moisture content of the hydrous crumb after drying in the 5th drying barrel: 0.4%
Rubber temperature:
-Temperature of the hydrous crumb supplied to the first supply barrel: 65 ° C.
-Temperature of rubber discharged from screw type extruder: 140 ℃
Set temperature of each barrel:
-First dehydration barrel: 90 ° C
-Second dehydration barrel: 100 ° C
-Third dehydration barrel: 120 ° C
-First drying barrel: 120 ° C
-Second drying barrel: 130 ° C
-Third drying barrel: 140 ° C
・ Fourth drying barrel: 160 ° C
・ Fifth drying barrel: 180 ° C
Operating conditions:
-Screw diameter (D) in the barrel unit: 132 mm
-Overall length (L) of the screw in the barrel unit: 4620 mm
・ L / D: 35
・ Rotation speed of screw in barrel unit: 135 rpm
-Rubber extrusion amount from die: 700 kg / hr
・ Die resin pressure: 2MPa

The extruded sheet-shaped dry rubber was cooled to 50 ° C., cut with a cutter, and laminated to 20 parts (20 kg) before the temperature fell below 40 ° C. to obtain an acrylic rubber veil (A). .. Reactive group content, ash content, ash component content, specific gravity, gel amount, glass transition temperature (Tg), pH, antiaging agent content, water content, molecular weight, molecular weight distribution of the obtained acrylic rubber veil (A) And the complex viscosity was measured and the results are shown in Tables 3-1 and 3-2.

Next, using a Banbury mixer, 100 parts of the acrylic rubber bale (A) and the compounding agent A of "Formulation 1" shown in Table 2 were added and mixed at 50 ° C. for 5 minutes. The BIT at this time was measured to evaluate the processability of the acrylic rubber bale, and the results are shown in Tables 3-1 and 3-2.

Then, the obtained mixture was transferred to a roll at 50 ° C., and the compounding agent B of "Formulation 1" shown in Table 2 was mixed and mixed to obtain a rubber mixture. A cross-linking test of the rubber mixture using the acrylic rubber veil (A) was performed before and after the storage stability test, changes in the cross-linking density (MH-ML) were measured, and the results are shown in Tables 3-1 and 3-2. The cross-linking (vulcanization) conditions at this time were as follows: primary vulcanization at 180 ° C. for 10 minutes and secondary vulcanization at 180 ° C. for 2 hours.

The obtained rubber mixture was placed in a mold having a length of 15 cm, a width of 15 cm, and a depth of 0.2 cm, and was first crosslinked by pressing at 180 ° C. for 10 minutes while pressurizing at a press pressure of 10 MPa, and then the obtained primary was obtained. The crosslinked product was further heated in a gear oven at 180 ° C. for 2 hours for secondary cross-linking to obtain a sheet-shaped rubber crosslinked product. Then, a 3 cm × 2 cm × 0.2 cm test piece was cut out from the obtained sheet-shaped rubber crosslinked product, and the water resistance evaluation and the normal physical properties were evaluated, and the results are shown in Tables 3-1 and 3-2.

[Example 2]
The monomer component was 4.5 parts of ethyl acrylate, 64.5 parts of n-butyl acrylate, 29.5 parts of methoxyethyl acrylate and 1.5 parts of mono n-butyl fumarate, and the emulsifier was nonylphenyloxy. Acrylic rubber sheet (B) and acrylic rubber bale (B) were obtained in the same manner as in Example 1 except that the hexaoxyethylene phosphate sodium salt and the anti-aging agent-containing emulsion were changed to anti-emulsifier emulsion 2. The characteristics were evaluated. The results are shown in Tables 3-1 and 3-2.

[Example 3]
The monomer component is 48.25 parts of ethyl acrylate, 50 parts of n-butyl acrylate and 1.75 parts of mono n-butyl fumarate, and the emulsifier is tridecyloxyhexaoxyethylene phosphate sodium salt. The same procedure as in Example 1 was carried out except that the anti-aging agent-containing emulsion was changed to anti-aging emulsion 3, and the acrylic rubber sheet (C) and acrylic rubber bale (C) were obtained and each characteristic (the compounding agent was changed to "formulation 2"). And evaluated). The results are shown in Tables 3-1 and 3-2.

[Example 4]
The temperature of the first dehydration barrel of the screw type extruder is changed to 100 ° C. and the temperature of the second dehydration barrel is changed to 120 ° C. so that drainage is performed only in the first dehydration barrel, and after drainage in the first barrel. Acrylic rubber sheet (D) and acrylic rubber bale (D) were obtained in the same manner as in Example 3 except that the water content of the water-containing crumb was changed to 30%, and each characteristic was evaluated. The results are shown in Tables 3-1 and 3-2.

[Example 5]
Acrylic rubber was carried out in the same manner as in Example 4 except that the monomer component was changed to 28 parts of ethyl acrylate, 38 parts of n-butyl acrylate, 27 parts of methoxyethyl acrylate, 5 parts of acrylonitrile and 2 parts of allylglycidyl ether. A sheet (E) and an acrylic rubber bale (E) were obtained, and each characteristic (the compounding agent was changed to "formulation 3") was evaluated. The results are shown in Tables 3-1 and 3-2.

[Example 6]
Example 4 except that the monomer component is changed to 42.2 parts of ethyl acrylate, 35 parts of n-butyl acrylate, 20 parts of methoxyethyl acrylate, 1.5 parts of acrylonitrile and 1.3 parts of vinyl chloroacetate. The same procedure as above was carried out to obtain an acrylic rubber sheet (F) and an acrylic rubber bale (F), and each characteristic (the compounding agent was changed to "formulation 4") was evaluated. The results are shown in Tables 3-1 and 3-2.

[Example 7]
Acrylic rubber sheet (G) and acrylic rubber bale (G) were obtained in the same manner as in Example 6 except that the anti-aging agent-containing emulsion was changed to anti-aging emulsion 4, and each characteristic was evaluated. The results are shown in Tables 3-1 and 3-2.

[Example 8]
Acrylic rubber sheet (H) and acrylic rubber veil (H) were obtained in the same manner as in Example 6 except that the anti-aging agent-containing emulsion was changed to anti-aging emulsion 5, and each characteristic was evaluated. The results are shown in Tables 3-1 and 3-2.

[Comparative Example 1]
In a mixing container equipped with a homomixer, 46 parts of pure water, 42.2 parts of ethyl acrylate, 35 parts of n-butyl acrylate, 20 parts of methoxyethyl acrylate, 1.5 parts of acrylonitrile, 1.3 parts of vinyl chloroacetate As an emulsifier, 0.709 parts of sodium lauryl sulfate and 1.82 parts of polyoxyethylene dodecyl ether (molecular weight 1500) were charged and stirred to obtain a monomer emulsion.

Next, 170 parts of pure water and 3 parts of the monomer emulsion obtained above were put into a polymerization reaction tank equipped with a thermometer and a stirrer, and cooled to 12 ° C. under a nitrogen stream. Next, the remainder of the monomer emulsion, 0.00033 parts of ferrous sulfate, 0.264 parts of sodium ascorbate, and 0.22 parts of potassium persulfate were continuously added dropwise to the polymerization reaction tank over 3 hours. .. After that, the reaction was continued while the temperature in the polymerization reaction was kept at 23 ° C., it was confirmed that the polymerization conversion rate reached approximately 100%, and hydroquinone as a polymerization terminator was added to stop the polymerization reaction. Then, the anti-aging emulsion 6 shown in Table 1 was added as an anti-aging agent-containing emulsion to obtain an emulsion polymer solution to which the anti-aging agent was added.

Next, a 0.7% sodium sulfate aqueous solution (coagulation solution) was continuously added to an emulsion polymerization solution (rotation speed 100 rpm, peripheral speed 0.5 m / s) heated to 80 ° C. to coagulate the polymer and filter it. A hydrous crumb was obtained. To 100 parts of the obtained water-containing crumb, 194 parts of industrial water was added, and after stirring at 25 ° C. for 5 minutes, the water-containing crumb for discharging water from the coagulation tank was washed four times, and then a sulfuric acid aqueous solution having a pH of 3 194. After adding the part and stirring at 25 ° C. for 5 minutes, water is discharged from the coagulation tank to perform acid cleaning once, then 194 parts of pure water is added and pure water cleaning is performed once, and then 160 ° C. A crumb-shaped acrylic rubber (I) having a water content of 0.4% by weight was obtained by drying with a hot air dryer. Each characteristic of the obtained crumb-shaped acrylic rubber (I) was evaluated and shown in Tables 3-1 and 3-2.

[Comparative Example 2]
A crumb-shaped acrylic rubber (J) was obtained in the same manner as in Comparative Example 1 except that the anti-aging agent-containing emulsion was changed to the anti-aging emulsion 7. Each characteristic of the obtained crumb-shaped acrylic rubber (J) was evaluated and shown in Tables 3-1 and 3-2.

From Tables 3-1, 3-2, it has the reactive group of the present invention, the weight average molecular weight (Mw) is 100,000 to 5,000,000, and the z average molecular weight (Mz) and the weight average molecular weight (Mw) are shown. Acrylic rubber veil (A) to which is composed of acrylic rubber having a ratio (Mz / Mw) of 1.3 or more, contains a phenolic antioxidant, and has a gel amount of 50% by weight or less of an insoluble methyl ethyl ketone. It can be seen that (H) is remarkably excellent in storage stability and processability, and is also excellent in state physical properties including strength characteristics and water resistance (Examples 1 to 8).
Regarding the strength characteristics, the acrylic rubber veils (A) to (H) and the crumb-shaped acrylic rubbers (I) to (J) produced under the conditions of Examples and Comparative Examples of the present application have absolute molecular weights measured by GPC-MALS. The ratio (Mz /) of the z average molecular weight (Mz) and the weight average molecular weight (Mw) of the absolute molecular weight distribution with an emphasis on the high molecular weight region measured by GPC-MALS and the weight average molecular weight (Mw) exceeding 100,000. Since Mw) is larger than 1.3, it can be seen that the normal physical properties including the breaking strength are all excellent (Examples 1 to 6 and Comparative Examples 1 to 2). However, from Table 2, the crumb-shaped acrylic rubber (I) of Comparative Example 1 is inferior in storage stability, processability and water resistance, and the crumb-shaped acrylic rubber (J) is extremely poor in storage stability and water resistance. It turns out to be inferior.

Regarding storage stability, the anti-aging agent content of the acrylic rubber veils (A) to (H) is the same as that of the crumb-shaped acrylic rubber (I). Due to the overwhelming difference in the oxidation ratio surface area, the phenolic anti-aging agent is uniformly and finely dispersed in the acrylic rubber veils (A) to (H), which greatly stabilizes the storage. It seems to have been improved (comparison between Examples 1 to 8 and Comparative Example 1). In addition, after the storage stability test, no change in color tone was observed in the acrylic rubber veils (A) to (H), but the crumb-shaped acrylic rubbers (I) to (J) were yellowed, which was also crumb-shaped. This is probably the result of the difference in specific surface area between the veil and the veil.

From Tables 3-1 and 3-2, the acrylic rubber veils (A) to (H) of the present invention are prepared by using a phenolic antiaging agent added to the emulsion polymer solution with water and an emulsifier to prevent phenolic aging. By making the agent-containing emulsion and setting the emulsifier concentration of the phenol-based anti-aging agent-containing emulsion to a predetermined value or higher and the water temperature at the time of preparation to a predetermined value or higher or the melting point of the phenol-based anti-aging agent or higher, the storage stability is remarkably improved. (Comparison between Examples 1 to 7 and Example 8). It is considered that increasing the emulsion dispersibility of these phenol-based anti-aging agents enhances the dispersibility of the phenol-based anti-aging agents in acrylic rubber and shows great storage stability.

Regarding processability, in the present invention, the polymerization conversion rate of emulsion polymerization is increased in order to improve the strength characteristics, but as the polymerization conversion rate is increased, the gel amount of the insoluble methyl ethyl ketone rapidly increases and the processing of acrylic rubber is performed. Although the properties are deteriorated, the gel of methyl ethyl ketone insoluble content that rapidly increased by drying and kneading in a screw type extruder to a state where there is no water (water content less than 1%) has almost disappeared. The processability of the acrylic rubber veils (A) to (H) has been greatly improved (comparison between Examples 1 to 8 and Comparative Examples 1 and 2).

Regarding water resistance, from Tables 3-1 and 3-2, the acrylic rubber sheets (A) to (H) of the present invention are overwhelmingly superior to the crumb-shaped acrylic rubbers (I) to (J). (Comparison between Examples 1 to 8 and Comparative Examples 1 and 2). This is because the amount of ash in the acrylic rubber veil was reduced by squeezing water from the water-containing crumb to a specific water content in the dehydration step, and a phosphate ester salt was used as an emulsifier and a magnesium salt was used as a coagulant. The water resistance of the acrylic rubber sheets (A) to (H) is improved by the fact that the ash content remaining in the acrylic rubber veil at the time of use has a high content of magnesium and phosphorus and has almost no effect on the water resistance when both are in a specific ratio. It can be seen that it has been significantly improved (Examples 1 to 8). Further, from Tables 3-1 and 3-2, when Example 8 and Comparative Example 1 are compared, the ash content of Example 8 is reduced to nearly half of that of Comparative Example 1, but the water resistance is 10 times higher. You can see that it has been improved. It can be seen that the ash containing a large amount of phosphorus and magnesium is superior in water resistance to the ash containing a large amount of sodium and sulfur.

From Tables 3-1, 3-2, the specific gravity, gel amount, glass transition temperature (Tg), pH, anti-aging agent content, water content, weight average molecular weight (Mw), which further contains a phenolic anti-aging agent, Ratio of z average molecular weight (Mz) to weight average molecular weight (Mw) (Mz / Mw), complex viscosity η (100 ° C) at 100 ° C, complex viscosity η (60 ° C) at 60 ° C, 100 ° C and 60 Acrylic rubber veils A) to (H) having a ratio of complex viscosity at ° C. (η100 ° C./η60 ° C.) in a specific range are highly excellent in storage stability and workability without impairing normal physical properties including strength characteristics. It can be seen that it is also excellent in water resistance (Examples 1 to 8).

[Reference example 1]
A crumb-shaped acrylic rubber (K) was obtained in the same manner as in Comparative Example 1 except that the emulsifier was changed to 1,8 parts of tridecyloxyhexaoxyethylene phosphate sodium salt and the coagulant was changed to magnesium sulfate. When the ash content of the crumb-shaped acrylic rubber (K) was measured, it greatly exceeded 1%, and the ash content when the phosphate ester salt was used as the emulsifier and magnesium sulfate was used as the coagulant could not be sufficiently removed by washing alone. I found out. The acrylic rubber veils (A) to (H) of the present invention generate a water-containing crumb that can easily remove ash by washing and dehydration by increasing a specific coagulation method, a specific coagulant concentration, and a stirring speed, and It can be seen that the amount of ash is greatly reduced and the water resistance is improved by dehydrating after washing with warm water.

1 Acrylic rubber manufacturing system 3 Coagulation equipment 4 Cleaning equipment 5 Screw type extruder 6 Cooling equipment 7 Bale equipment

Claims (46)

It has a reactive group, has a weight average molecular weight (Mw) of 100,000 to 5,000,000, and has a ratio (Mz / Mw) of z average molecular weight (Mz) to weight average molecular weight (Mw) of 1.3 or more. Acrylic rubber veil made of acrylic rubber, containing a phenolic anti-aging agent, and having a gel amount of 50% by weight or less of an insoluble methyl ethyl ketone. The acrylic rubber veil according to claim 1, wherein the content of the phenolic antiaging agent is 0.001 to 15% by weight. The acrylic rubber veil according to claim 1 or 2, wherein the phenol-based anti-aging agent is a hindered phenol-based anti-aging agent. The acrylic rubber veil according to any one of claims 1 to 3, wherein the phenolic antiaging agent has a melting point of 150 ° C. or lower. The acrylic rubber veil according to any one of claims 1 to 4, wherein the phenolic antiaging agent has a molecular weight in the range of 100 to 1000. Acrylic rubber is at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl esters and (meth) acrylic acid alkoxyalkyl esters, reactive group-containing monomers, and optionally. The acrylic rubber bale according to any one of claims 1 to 5, which is composed of other copolymerizable monomers. The acrylic rubber veil according to any one of claims 1 to 6, wherein the reactive group is at least one functional group selected from the group consisting of a carboxyl group, an epoxy group and a halogen group. The acrylic rubber veil according to any one of claims 1 to 7, wherein the weight average molecular weight (Mw) is in the range of 1,000,000 to 5,000,000. The acrylic rubber veil according to any one of claims 1 to 8, wherein the complex viscosity ([η] 100 ° C.) at 100 ° C. is in the range of 1500 to 6000 Pa · s. When the ratio ([η] 100 ° C / [η] 60 ° C) of the complex viscosity at 100 ° C ([η] 100 ° C) to the complex viscosity at 60 ° C ([η] 60 ° C) is 0.5 or more. The acrylic rubber bale according to any one of claims 1 to 9. When the ratio ([η] 100 ° C / [η] 60 ° C) of the complex viscosity at 100 ° C ([η] 100 ° C) to the complex viscosity at 60 ° C ([η] 60 ° C) is 0.8 or more. The acrylic rubber bale according to any one of claims 1 to 10. The acrylic rubber veil according to any one of claims 1 to 11, which has a specific gravity of 0.7 or more. The acrylic rubber veil according to any one of claims 1 to 12, which has a specific gravity of 0.8 or more. The acrylic rubber veil according to any one of claims 1 to 13, wherein the amount of gel of the insoluble methyl ethyl ketone is 5% by weight or less. The acrylic rubber veil according to any one of claims 1 to 14, which has a pH of 6 or less. The acrylic rubber veil according to any one of claims 1 to 15, wherein the ash content is 0.5% by weight or less. Any one of claims 1 to 16 in which the content of at least one element selected from the group consisting of sodium, sulfur, calcium, magnesium and phosphorus in the ash content is 50 % by weight or more as a ratio to the total ash content. Acrylic rubber veil as described in the section. The acrylic rubber veil according to any one of claims 1 to 17, wherein the total amount of magnesium and phosphorus in the ash content is 50% by weight or more as a ratio to the total ash content. The acrylic rubber veil according to any one of claims 1 to 18, wherein the ratio of magnesium to phosphorus in the ash ([Mg] / [P]) is in the range of 0.4 to 2.5. The acrylic rubber veil according to any one of claims 1 to 19, wherein the acrylic rubber is obtained by emulsion polymerization. The acrylic rubber veil according to any one of claims 1 to 20, wherein the acrylic rubber is polymerized using a phosphate ester salt or a sulfate ester salt as an emulsifier. The acrylic rubber veil according to any one of claims 1 to 21, wherein the acrylic rubber is polymerized using a redox catalyst composed of a radical generator and a reducing agent. The acrylic rubber veil according to any one of claims 1 to 22, wherein the acrylic rubber is polymerized to a polymerization conversion rate of 80% by weight or more. The acrylic rubber veil according to any one of claims 1 to 23, wherein the acrylic rubber is obtained by adding a phenolic antiaging agent to an emulsion polymerization solution after emulsion polymerization, coagulating and drying the mixture. The acrylic rubber veil according to any one of claims 1 to 24, wherein the acrylic rubber is obtained by coagulating an emulsion polymerization solution with an alkali metal salt or a metal salt of Group 2 of the periodic table and drying it. The acrylic rubber veil according to any one of claims 1 to 25, wherein the acrylic rubber is obtained by drying a hydrous crumb produced after solidifying an emulsion polymerization solution. The acrylic rubber veil according to claim 26, wherein the proportion of the produced hydrous crumbs that pass through a JIS sieve having a mesh size of 6.7 mm but do not pass through a JIS sieve having a mesh size of 710 μm is 20% by weight or more. The acrylic rubber veil according to any one of claims 1 to 27, wherein the acrylic rubber is obtained by washing a hydrous crumb with warm water and then drying it. The acrylic rubber veil according to any one of claims 1 to 28, wherein the acrylic rubber is obtained by dehydrating a water-containing crumb to a water content of 1 to 50% by weight and then drying it. The acrylic rubber veil according to any one of claims 1 to 29, wherein the acrylic rubber is dried under reduced pressure after solidification. The acrylic rubber veil according to any one of claims 1 to 30, wherein the acrylic rubber is melt-kneaded and dried after solidification. The acrylic rubber veil according to claim 31, wherein the melt kneading is carried out in a state of substantially no moisture. The acrylic rubber veil according to any one of claims 24 to 32, wherein the drying is performed by a screw type extruder. The acrylic rubber veil according to any one of claims 24 to 33, which is cooled at a cooling rate of 50 ° C./hr or more after the drying. A rubber mixture obtained by mixing a filler and a cross-linking agent with the acrylic rubber veil according to any one of claims 1 to 34. The rubber mixture according to claim 35 , wherein the filler is a reinforcing filler. The rubber mixture according to claim 35 , wherein the filler is carbon black. The rubber mixture according to claim 35 , wherein the filler is silica. The rubber mixture according to any one of claims 35 to 38 , wherein the cross-linking agent is a polyvalent amine compound, an ammonium carboxylate salt, a metal dithiocarbamic acid salt or a triazine thiol compound. The rubber mixture according to any one of claims 35 to 39 , which is obtained by further mixing an antiaging agent. The rubber mixture according to claim 40 , wherein the anti-aging agent is an amine-based anti-aging agent. A method for producing a rubber mixture, which comprises mixing a filler, a cross-linking agent and, if necessary, an antiaging agent with the acrylic rubber veil according to any one of claims 1 to 34 using a mixer. A method for producing a rubber mixture, wherein the acrylic rubber veil according to any one of claims 1 to 34, a filler, and an antiaging agent, if necessary, are mixed, and then a cross-linking agent is mixed. A rubber crosslinked product obtained by cross-linking the rubber mixture according to any one of claims 35 to 41 . The rubber crosslinked product according to claim 44 , wherein the cross-linking is a primary cross-linking and a secondary cross-linking. A method for producing a rubber crosslinked product, wherein the rubber mixture according to any one of claims 35 to 41 is primarily crosslinked and then secondarily crosslinked.

Images