JP6828842B2 - Acrylic rubber veil with excellent workability and water resistance - Google Patents

Description

The present invention relates to an acrylic rubber bale and a method for producing the same, a rubber mixture and the method for producing the same, and a rubber crosslinked product. More specifically, the acrylic rubber bale having excellent processability and water resistance and the method for producing the same, and the acrylic rubber bale are mixed. The present invention relates to a rubber mixture made of, a method for producing the same, and a rubber crosslinked product obtained by cross-linking the rubber mixture.

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, and is widely used in automobile-related fields and the like.

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 bringing a polymer latex into contact 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 the moisture-removed crumb-like rubber polymer 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 ethyl acrylate / n-butyl acrylate copolymer and ethyl acrylate / It has been shown that it can be applied to a copolymer 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.

As acrylic rubber having a reactive group having excellent strength characteristics and heat resistance, for example, Patent Document 2 (International Publication No. 2018/116828 pamphlet) describes ethyl acrylate, n-butyl acrylate and mono n-humalate. Acrylic rubber latex obtained by emulsifying a monomer component composed of butyl with sodium lauryl sulfate as an emulsifier, polyethylene glycol monostearate, and water and emulsion polymerization in the presence of a polymerization initiator until the polymerization conversion rate reaches 95% is sulfated. After adding magnesium to an aqueous solution of a polymer flocculant dimethylamine-ammonia-epichlorohydrin polycondensate, the mixture is stirred at 85 ° C. to form a crumb slurry, and then the crumb slurry is washed once with water and then 100. A method of recovering a crumb-shaped acrylic rubber by passing the entire amount through a mesh 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-coagulated hydrous crumbs generated in the coagulation reaction and a large amount of adhering to the coagulation tank, and problems such as insufficient removal of coagulants and emulsifiers by washing. Even if it was produced, there was a problem that it was inferior in processability and water resistance.

Further, in Patent Document 3 (International Publication No. 2018/079783 pamphlet), a monomer component composed of ethyl acrylate, n-butyl acrylate and mono n-butyl fumarate is contained in pure water, sodium lauryl sulfate and polyoxy. Emulsified using an emulsifier made of ethylene dodecyl ether and emulsion-polymerized to a polymerization conversion rate of 95% by weight in the presence of a polymerization initiator to obtain an emulsion polymerization solution, and a hydrous crumb is produced by continuously adding sodium sulfate. Then, the produced hydrous crumb was washed with industrial water four times, acid-washed at pH 3 once, and pure water-washed once, and then dried at 110 ° C. for 1 hour in a hot air dryer. A method for producing an acrylic rubber having an excellent water resistance (volume change after immersion in 80 ° C. distilled water for 70 hours) with a small residual amount of an emulsifier or a coagulant is disclosed. However, it is not described that it is molded into a veil shape and used, and handling the adhesive acrylic rubber in a crumb shape has a problem that workability and storage stability are inferior. Further, in terms of improvement in workability and water resistance, a high degree of water resistance in a harsher environment is required.

Japanese Unexamined Patent Publication No. 2006-328239 International Publication No. 2018/116828 Pamphlet International Publication No. 2018/079783 Pamphlet

The present invention has been made in view of the actual conditions of the prior art, and crosslinks an acrylic rubber bale having excellent workability and water resistance and a method for producing the same, a rubber mixture containing the acrylic rubber bale and the method for producing the same, and a rubber mixture. It is an object of the present invention to provide a rubber crosslinked product.

As a result of diligent research in view of the above problems, the present inventors have specified an amount of gel which is composed of acrylic rubber having a reactive group, has a large proportion of magnesium and phosphorus in the ash content, and is insoluble in methyl ethyl ketone at a specific ash content. We have found that the proportioned acrylic rubber veil is highly processable and water resistant.

In addition, the present inventors coagulate an emulsion polymerization solution obtained by emulsion-polymerizing a monomer component containing a reactive group-containing monomer in the presence of a phosphoric acid-based emulsifier with a magnesium salt, and then wash the acrylic rubber veil. It was found that the hydrous crumb can be easily produced by drying and veiling with a screw type extruder. In addition, the shape and crumb diameter of the hydrous crumb generated by a specific method or a specific range of the coagulation reaction addition method, coagulation liquid concentration, coagulation liquid temperature, rotation speed and peripheral speed during coagulation liquid agitation, etc. should be adjusted. And by washing the hydrous crumbs thus obtained with warm water, it was found that the coagulant used could be almost completely removed in the washing step. Then, the ash derived from the emulsifier that cannot be completely removed by washing (in the present invention, the phosphoric acid-based emulsifier is ion-exchanged with the magnesium salt of the coagulant) can be easily removed by squeezing out in the dehydration step. We have found that acrylic rubber veils can be manufactured. In addition, the amount of gel that is insoluble in the methyl ethyl ketone generated in a large amount in the emulsion polymerization step is increased by drying and extruding the water-containing crumb after washing to a state where there is virtually no water content (below the specified water content) with a screw extruder. It was found that an acrylic rubber bale that disappeared and had extremely excellent workability could be manufactured.

Furthermore, the present inventors have washed the hydrous crumb generated in the solidification step, and then dehydrated and dried it with a specific screw type extruder to make characteristic values such as ash content, gel amount, and specific gravity suitable, and acrylic rubber veil. The effect of the present invention is remarkably improved, and the dry rubber extruded by the screw type extruder is layered in a sheet shape to form a bale and integrated to form an acrylic rubber bale with a specific specific gravity containing almost no bubbles. It has been found that the effect of the present invention is further improved.

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

Thus, according to the present invention, it is made of acrylic rubber having a reactive group, the ash content is 0.6% by weight or less, and the total amount of magnesium and phosphorus in the ash content is 30% by weight or more as a ratio to the total ash content. An acrylic rubber veil is provided in which the amount of gel of the insoluble methyl ethyl ketone is 50% by weight or less.

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 in proportion to the total ash content.

In the acrylic rubber veil of the present invention, the total amount of magnesium and phosphorus in the ash content is preferably 80% by weight or more in proportion to the total ash content.

In the acrylic rubber veil of the present invention, the acrylic rubber has at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester. Is preferable.

In the acrylic rubber veil of the present invention, it is preferable that the reactive group in the acrylic rubber is 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 reactive group content is preferably in the range of 0.001 to 5% by weight.

In the acrylic rubber veil of the present invention, the complex viscosity at 60 ° C. ([η] 60 ° C.) is preferably 15,000 Pa · s or less.

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 specific gravity is preferably in the range of 0.7 to 1.5.

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 ash content is preferably 0.001 to 0.5% by weight.

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 glass transition temperature (Tg) is preferably 20 ° C. or lower.

In the acrylic rubber veil of the present invention, the Mooney viscosity (ML1 + 4,100 ° C.) is preferably in the range of 10 to 150.

According to the present invention, a monomer component containing a (meth) acrylic acid ester and a reactive group-containing monomer is emulsionized with water and a phosphoric acid-based emulsifier, and a redox consisting of a radical generator and a reducing agent. An emulsion polymerization step of emulsion-polymerizing the monomer component in the presence of a catalyst to obtain an emulsion polymerization solution, and a coagulation step of contacting the obtained emulsion polymerization solution with a magnesium salt aqueous solution as a coagulant to form a water-containing crumb. , A washing step of washing the generated water-containing crumb, a dehydration step of dehydrating the washed water-containing crumb, and a water-containing crumb whose water content was reduced in the dehydration step are dried by a screw type extruder to have a water content of less than 1% by weight. Provided is a method for producing an acrylic rubber bale, which comprises a drying step of obtaining a dry rubber and a bale step of bale of a dry rubber having a water content of less than 1% by weight.

In the method for producing an acrylic rubber bale of the present invention, after the cleaning step, a dehydration step of dehydrating the washed hydrous crumb with a dehydrator is provided, and the hydrous crumb having a reduced water content in the dehydration step is supplied to the drying step. It is preferable to do so. As a suitable dehydrator, for example, a screw type extruder described later can be mentioned.

In the method for producing an acrylic rubber bale of the present invention, it is preferable that the contact between the emulsion polymerization solution and the magnesium salt aqueous solution is carried out by adding the emulsion polymerization solution to the stirred magnesium salt aqueous solution.

In the method for producing an acrylic rubber veil of the present invention, the rotation speed of the agitated magnesium salt aqueous solution is preferably 100 rpm or more.

In the method for producing an acrylic rubber veil of the present invention, the peripheral speed of the agitated magnesium salt aqueous solution is preferably 0.5 m / s or more.

In the method for producing an acrylic rubber veil of the present invention, the magnesium salt concentration of the magnesium salt aqueous solution is preferably 0.5% by weight or more.

In the method for producing an acrylic rubber veil of the present invention, it is preferable that the hydrous crumbs produced in the solidification step satisfy the following (a) to (e).
(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.
(B) 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 crumbs that pass through a 6.7 mm mesh JIS sieve and do not pass through a 710 μm JIS sieve is 20% by weight or more.
(D) 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.

In the method for producing an acrylic rubber veil of the present invention, it is preferable to wash the hydrous crumb with warm water. Further, it is preferable to dehydrate the washed water-containing crumb to a water content of 1 to 50% by weight.

In the method for producing an acrylic rubber bale of the present invention, the dehydration step and the drying step are carried out by using a dehydration barrel having a dehydration slit, a drying barrel for drying under reduced pressure, and a screw type extruder having a die at the tip. It is preferable that the water-containing crumb is dehydrated in the dehydration barrel to a water content of 1 to 50% by weight, dried in the drying barrel to a water content of less than 1% by weight, and the dried rubber is extruded from the die.

In the method for producing an acrylic rubber veil of the present invention, it is preferable that the dry rubber is a sheet-shaped dry rubber.

In the method for producing an acrylic rubber veil of the present invention, it is preferable that the bale is formed by laminating sheet-shaped dry rubber.

According to the present invention, there is provided a rubber mixture obtained by mixing a filler and a cross-linking agent with the acrylic rubber veil.

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

According to the present invention, there is provided a method for producing a rubber mixture, which comprises mixing a filler with the acrylic rubber veil and then mixing a cross-linking agent.

According to the present invention, a rubber crosslinked product obtained by crosslinking the above rubber mixture is provided.

According to the present invention, an acrylic rubber bale having excellent processability and water resistance and a method for producing the same, a rubber mixture containing the acrylic rubber veil and a method for producing the same, and a crosslinked rubber product are 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 veil of the present invention is made of acrylic rubber having a reactive group, has an ash content of 0.6% by weight or less, and the total amount of magnesium and phosphorus in the ash content is 30% by weight or more as a ratio to the total ash content. The gel amount of the insoluble methyl ethyl ketone is 50% by weight or less.

<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 depending on 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. It is suitable because the cross-linking property of the acrylic rubber veil can be highly improved when it is a group. 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 required.

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) alkoxyalkyl ester is not particularly limited, but usually has 2 to 12 alkoxyalkyl groups (meth) acrylic acid alkoxyalkyl ester, preferably 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) acrylate 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 may 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 according to the purpose of use without any particular limitation, but is a single amount having at least one functional group selected from the group consisting of a carboxyl group, an epoxy group and a halogen group. The body is preferable, a monomer having an ionic reactive group such as a carboxyl group and an epoxy group is more preferable, and 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 characteristics when the acrylic rubber veil is a rubber cross-linked product.

The ethylenically unsaturated monocarboxylic acid is not particularly limited, but an ethylenically unsaturated monocarboxylic acid having 3 to 12 carbon atoms is preferable, and for example, acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, etc. Examples thereof include crotonic acid.

The ethylenically unsaturated dicarboxylic acid is not particularly limited, but an ethylenically unsaturated dicarboxylic acid having 4 to 12 carbon atoms is preferable, and for example, butenedioic acid such as fumaric acid and maleic acid, itaconic acid, citraconic acid, and chloro. Maleic acid and the like 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 is 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. Ethylene unsaturated dicarboxylic acid 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, and monocyclohexyl maleate; 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; an epoxy group-containing vinyl ether such as allyl glycidyl ether and vinyl glycidyl ether; and the like.

The halogen group of the monomer having a halogen group is not particularly limited, but is preferably a chlorine atom. Examples of the monomer having such a halogen group include unsaturated alcohol esters of halogen-containing saturated carboxylic acids, (meth) acrylic acid haloalkyl esters, (meth) acrylic acid haloacyloxyalkyl esters, and (meth) acrylic acids (haloacetyls). Carbamoyloxy) 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.

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, and 1,2-dichloroethyl (meth) acrylic acid. 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 (meth) acrylic acid 2- (chloroacetylcarbamoyloxy) ethyl and (meth) acrylic acid 3- (chloroacetylcarbamoyloxy) propyl. 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) propylallyl ether and p-vinylbenzylchloroacetic acid ester.

Each of these reactive group-containing monomers is 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, most preferably 1 to 3% by weight.

The other monomer is not particularly limited as long as it can be copolymerized with the above-mentioned monomer and is used as needed. For example, aromatic vinyl, ethylenically unsaturated nitrile, acrylamide-based monomer, etc. 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 chloride, vinylidene chloride, vinyl acetate, ethyl vinyl ether, and butyl vinyl ether.

The above-mentioned 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, more preferably 0 to 0. It is in the range of 15% by weight, most preferably 0 to 10% by weight.

<Acrylic rubber>
The acrylic rubber constituting the acrylic rubber veil of the present invention is characterized by having the above-mentioned reactive group in its molecular chain. 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 properties, 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. It is suitable because the characteristics are highly balanced.

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. The binding unit derived from 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, and more preferably 80 to 99.5% by weight. %, Especially preferably in the range of 87 to 99% by weight, and the bonding unit derived from the reactive group-containing monomer is usually 0.01 to 20% by weight, preferably 0.1 to 10% by weight, more preferably. It is in the range of 0.5 to 5% by weight, particularly preferably 1 to 3% by weight, and the binding unit derived from other monomers is usually 0 to 30% by weight, preferably 0 to 20% by weight, more preferably. It is in the range of 0 to 15% by weight, particularly preferably 0 to 10% by weight. By setting the bonding unit derived from these monomers of acrylic rubber in this range, the object of the present invention can be highly achieved, and when the acrylic rubber veil is used as a crosslinked product, water resistance and compression resistance permanent strain resistance are remarkably improved. It is suitable because it is improved to.

The weight average molecular weight (Mw) of the acrylic rubber constituting the acrylic rubber veil of the present invention is not particularly limited, but is an absolute molecular weight measured by GPC-MALS, and is usually 100,000 to 5,000,000. It is preferably 500,000 to 5,000,000, more preferably 1,000,000 to 5,000,000, particularly preferably 1,100,000 to 3,500,000, and most preferably 1,200,000. When the range is in the range of ~ 2,500,000, the processability, strength characteristics, and compression-resistant permanent strain characteristics of the acrylic rubber bale when mixed are highly balanced, which is suitable.

The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the acrylic rubber constituting the acrylic rubber veil of the present invention is not particularly limited, but is absolutely measured by GPC-MALS. When the molecular weight distribution is usually in the range of 1.1 to 8, preferably 1.2 to 7, and more preferably 1.4 to 6, the processability, strength characteristics, and compression resistance permanent strain characteristics of the acrylic rubber bale are high. It is suitable because it is balanced with.

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 not particularly limited, but is measured by GPC-MALS. The processability and strength of the acrylic rubber bale when the absolute molecular weight distribution is focused on the polymer region and is usually in the range of 1.3 or more, preferably 1.4 to 5, more preferably 1.5 to 2. It is suitable because its properties are highly balanced and changes in physical properties during storage can be mitigated.

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, more preferably −40 ° C. or higher. By setting the glass transition temperature to the above-mentioned lower limit or higher, the oil resistance and heat resistance can be improved, and by setting the glass transition temperature to the above-mentioned 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 95% by weight or more, preferably 97% by weight or more, and more preferably 98% by weight or more.

<Acrylic rubber veil>
The acrylic rubber veil of the present invention is made of the acrylic rubber, and the ash content and the gel amount satisfy specific conditions. The ash content in the acrylic rubber veil is measured according to the JIS K6228 A method. In the production of acrylic rubber, the emulsifier used for emulsification and emulsion polymerization of the monomer component and the emulsion polymerization solution are coagulated. The main component is the residue of the coagulant used in the process.

The form of the acrylic rubber veil of the present invention is often a rectangular parallelepiped or a thick plate, and the size (dimensions) thereof is not particularly limited, but the width is usually 100 to 800 mm, preferably 200 to 200. In the range of 500 mm, more preferably 250-450 mm, the length is usually in the range of 300-1200 mm, preferably 400-1000 mm, more preferably 500-800 mm, and the height is usually 50-500 mm, preferably 100-300 mm. More preferably, it is in the range of 150 to 250 mm.

When the ash content of the acrylic rubber veil of the present invention is 0.6% by weight or less, preferably 0.5% by weight or less, more preferably 0.3% by weight or less, and most preferably 0.2% by weight or less. It is suitable because of its excellent storage stability and water resistance.

The lower limit of the ash content of the acrylic rubber veil of 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, when it is 0.005% by weight or more, and most preferably 0.01% by weight or more, metal adhesion is suppressed and workability is excellent.

The amount of phosphorus in the ash content of the acrylic rubber veil of the present invention is not particularly limited, but is usually 10% by weight or more, preferably 20% by weight or more, and more preferably 30% by weight or more in proportion to the total ash content. Particularly preferably, when it is 40% by weight or more, storage stability and water resistance are highly balanced and preferable.

The total amount of magnesium and phosphorus in the ash content of the acrylic rubber veil of the present invention 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, as a ratio to the total ash content. When it is% or more, 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 not particularly limited, but is usually 0.4 to 2.5, preferably 0 in terms of weight ratio. Storage stability and water resistance 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. Is highly excellent and is suitable.

The water content of the acrylic rubber veil of the present invention is not particularly limited, but is usually less than 1% by weight, preferably 0.8% by weight or less, and more preferably 0.6% by weight or less. Is optimized and has excellent properties such as heat resistance and water resistance, which is suitable.

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, more preferably 0.9 to 1.3, and particularly preferably. When it is in the range of 0.95 to 1.25, most preferably 1.0 to 1.2, the storage stability is highly excellent and suitable.

When 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 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. The storage stability is highly improved and is 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 2,000 to 10,000 Pa · s. , More preferably 2,500 to 7,000 Pa · s, and most preferably 2,700 to 5,500 Pa · s, which 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 1,500 to 6,000 Pa · s, preferably 2,000 to 5, It is excellent in processability, oil resistance, and shape retention when it is in the range of 000 Pa · s, more preferably 2,500 to 4,000 Pa · s, and most preferably 2,500 to 3,500 Pa · s. ..

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 to 0.98, more preferably 0.7 to 0.96, particularly preferably 0.8 to 0.95, and most preferably 0. When the range is in the range of 83 to 0.93, workability, oil resistance, and shape retention are 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 veil is not particularly limited, but for example, an emulsion of a monomer component containing a (meth) acrylic acid ester and a reactive group-containing monomer with water and a phosphoric acid-based emulsifier. An emulsion polymerization step of emulsion polymerization of a monomer component in the presence of a polymerization catalyst to obtain an emulsion polymerization solution, and a coagulation step of contacting the obtained emulsion polymerization solution with a magnesium salt aqueous solution as a coagulant to form a hydrous crumb. A washing step of washing the generated water-containing crumb, a dehydration step of dehydrating the washed water-containing crumb, and a dry rubber having a water content of less than 1% by weight dried by a screw type extruder whose water content was reduced in the dehydration step. It can be preferably carried out by the obtaining drying step and the bale step of bale the obtained dried rubber having a water content of less than 1% by weight.

(Emulsion polymerization process)
In the emulsion polymerization step in the method for producing an acrylic rubber veil of the present invention, a monomer component containing a (meth) acrylic acid ester and a reactive group-containing monomer is emulsionized with water and a phosphoric acid-based emulsifier, and a polymerization catalyst is present. It is characterized in that a monomer component is emulsion-polymerized underneath to obtain an emulsion polymerization solution.

The monomer component used in the emulsion polymerization step of acrylic rubber is the same as the above-mentioned example and preferable range of the monomer component.

The phosphoric acid-based emulsifier used in the emulsion polymerization step is not particularly limited as long as it is a phosphoric acid-based emulsifier normally used in the emulsion polymerization reaction, and is, for example, an alkyloxypolyoxyalkylene phosphate ester or a phosphoric acid-based emulsifier thereof. A divalent phosphoric acid-based emulsifier such as a salt, an alkylphenyloxypolyoxyalkylene phosphate ester or a salt thereof can be preferably used.

Examples of the alkyloxypolyoxyalkylene phosphate or its salt include an alkyloxypolyoxyethylene phosphate or a salt thereof, an alkyloxypolyoxypropylene phosphate or a salt thereof, and among these, alkyloxypoly Oxyethylene phosphate or a salt thereof is preferable, and alkyloxypolyoxyethylene phosphate is particularly preferable.

Examples of the alkyloxypolyoxyethylene phosphate or a salt thereof include octyloxydioxyethylene phosphate, octyloxytrioxyethylene phosphate, octyloxytetraoxyethylene phosphate, and decyloxytetraoxyethylene phosphate. Estel, dodecyloxytetraoxyethylene phosphate, tridecyloxytetraoxyethylene phosphate, tetradecyloxytetraoxyethylene phosphate, hexadecyloxytetraoxyethylene phosphate, octadecyloxytetraoxyethylene phosphate, Octyloxypentaoxyethylene Phosphate, Decyloxypentaoxyethylene Phosphate, Dodecyloxypentaoxyethylene Phosphate, Tridecyloxypentaoxyethylene Phosphate, Tetradecyloxypentaoxyethylene Phosphate, Hexadecyloxy Pentaoxyethylene Phosphate, Octadecyloxypentaoxyethylene Phosphate, Octyloxyhexaoxyethylene Phosphate, Decyloxyhexaoxyethylene Phosphate, Dodecyloxyhexaoxyethylene Phosphate, Tridecyloxyhexaoxyethylene Phosphate Acid ester, tetradecyloxyhexaoxyethylene phosphoric acid ester, hexadecyloxyhexaoxyethylene phosphoric acid ester, octadecyloxyhexaoxyethylene phosphoric acid ester, octyloxyoctaoxyethylene phosphoric acid ester, decyloxyoctaoxyethylene phosphoric acid ester, Dodecyloxyoctaoxyethylene phosphoric acid ester, tridecyloxyoctaoxyethylene phosphate ester, tetradecyloxyoctaoxyethylene phosphate ester, hexadecyloxyoctaoxyethylene phosphate ester, octadecyloxyoctaoxyethylene phosphate ester, etc. Examples thereof include those metal salts, preferably those metal salts, more preferably those alkali metal salts, and most preferably their sodium salts.

The alkyloxypolyoxypropylene phosphate or its salt is not particularly limited, but for example, octyloxydioxypropylene phosphate, octyloxytrioxypropylene phosphate, octyloxytetraoxypropylene phosphate, etc. Decyloxytetraoxypropylene phosphate ester, dodecyloxytetraoxypropylene phosphate ester, tridecyloxytetraoxypropylene phosphate ester, tetradecyloxytetraoxypropylene phosphate ester, hexadecyloxytetraoxypropylene phosphate ester, octadecyloxy Tetraoxypropylene Phosphate, Octyloxypentaoxypropylene Phosphate, Decyloxypentaoxypropylene Phosphate, Dodecyloxypentaoxypropylene Phosphate, Tridecyloxypentaoxypropylene Phosphate, Tetradecyloxypentaoxypropylene Phosylate, Hexadecyloxypentaoxypropylene Phosphate, Octadecyloxypentaoxypropylene Phosphate, Octyloxyhexaoxypropylene Phosphate, Decyloxyhexaoxypropylene Phosphate, Dodecyloxyhexaoxypropylene Phosphate, Tridecyloxyhexaoxypropylene phosphate ester, tetradecyloxyhexaoxypropylene phosphate ester, hexadecyloxyhexaoxypropylene phosphate ester, octadecyloxyhexaoxypropylene phosphate ester, octyloxyoctoxypropylene phosphate ester, decyloxy Octaoxypropylene Phosphate, Dodecyloxyoctaoxypropylene Phosphate, Tridecyloxyoctaoxyethylene Phosphate, Tetradecyloxyoctaoxypropylene Phosphate, Hexadecyloxyoctaoxypropylene Phosphate, Octadecyloxyoctaoxy Examples thereof include propylene phosphate and the like, and metal salts thereof, preferably those metal salts, more preferably those alkali metal salts, and most preferably their sodium salts.

Examples of the alkylphenyloxypolyoxyalkylene phosphate or its salt include alkylphenyloxypolyoxyethylene phosphate or its salt, alkylphenyloxypolyoxypropylene phosphate or its salt, and the like. Alkylphenyloxypolyoxyethylene phosphate salts are preferred.

Examples of the alkylphenyloxypolyoxyethylene phosphate or its salt include methyloxyoxytetraoxyethylene phosphate, ethylphenyloxytetraoxyethylene phosphate, butylphenyloxytetraoxyethylene phosphate, and hexylphenyloxy. Tetraoxyethylene Phosphate, Nonylphenyloxytetraoxyethylene Phosphate, Dodecylphenyloxytetraoxyethylene Phosphate, Octadecyloxytetraoxyethylene Phosphate, Methylphenyloxypentaoxyethylene Phosphate, Ethylphenyloxypenta Oxyethylene Phosphate, Butylphenyloxypentaoxyethylene Phosphate, Hexylphenyloxypentaoxyethylene Phosphate, Nonylphenyloxypentaoxyethylene Phosphate, Dodecylphenyloxypentaoxyethylene Phosphate, Methylphenyloxyhexa Oxyethylene Phosphate, Ethylphenyloxyhexaoxyethylene Phosphate, Butylphenyloxyhexaoxyethylene Phosphate, Hexylphenyloxyhexaoxyethylene Phosphate, Nonylphenyloxyhexaoxyethylene Phosphate, Dodecylphenyloxyhexa Oxyethylene Phosphate, Methylphenyloxyhexaoxyethylene Phosphate, Ethylphenyloxyoctaoxyethylene Phosphate, Butylphenyloxyoctaoxyethylene Phosphate, Hexylphenyloxyoctaoxyethylene Phosphate, Nonylphenyloxyocta Examples thereof include oxyethylene phosphate, dodecylphenyloxyoctaoxyethylene phosphate and the like, and their metal salts, preferably with their metal salts, more preferably with their alkali metal salts, most preferably with their sodium salts. is there.

The alkylphenyloxypolyoxypropylene phosphate or its salt is not particularly limited, but for example, methylphenyloxytetraoxypropylene phosphate, ethylphenyloxytetraoxypropylene phosphate, and butylphenyloxytetraoxypropylene. Phosylate, Hexylphenyloxytetraoxypropylene Phosphate, Nonylphenyloxytetraoxypropylene Phosphate, Dodecylphenyloxytetraoxypropylene Phosphate, Methylphenyloxypentaoxypropylene Phosphate, Ethylphenyloxypentaoxypropylene Phosylate, Butylphenyloxypentaoxypropylene Phosphate, Hexylphenyloxypentaoxypropylene Phosphate, Nonylphenyloxypentaoxypropylene Phosphate, Dodecylphenyloxypentaoxypropylene Phosphate, Methylphenyloxyhexaoxypropylene Phosylate, Ethylphenyloxyhexaoxypropylene Phosphate, Butylphenyloxyhexaoxypropylene Phosphate, Hexylphenyloxyhexaoxypropylene Phosphate, Nonylphenyloxyhexaoxypropylene Phosphate, Dodecylphenyloxyhexaoxypropylene Phosphate, Methylphenyloxyoctaoxypropylene Phosphate, Ethylphenyloxyoctaoxypropylene Phosphate, Butylphenyloxyoctaoxypropylene Phosphate, Hexylphenyloxyoctaoxyethylene Phosphate, Nonylphenyloxyoctaoxypropylene Examples thereof include phosphoric acid esters, dodecylphenyloxyoctaoxypropylene phosphate esters, and metal salts thereof, preferably those metal salts, more preferably their alkali metal salts, and most preferably their sodium salts.
Examples of the phosphoric acid-based emulsifier other than the above include monovalent phosphoric acid-based emulsifiers such as di (alkyloxypolyoxyalkylene) phosphoric acid ester salt; sodium lauryl phosphate, potassium lauryl phosphate and the like, preferably 1. It is a valent phosphoric acid-based emulsifier.

These phosphoric acid-based emulsifiers can be used alone or in combination of two or more, and suitable examples of combining two or more are a divalent phosphoric acid emulsifier and a monovalent phosphoric acid emulsifier. It is a combination. The amount of the phosphoric acid-based emulsifier used is usually in the range of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, and more preferably 1 to 3 parts by weight with respect to 100 parts by weight of the monomer component. is there.

In the present invention, other emulsifiers other than the above-mentioned phosphoric acid-based emulsifier may be used in combination with the above-mentioned phosphoric acid-based emulsifier, if necessary. Examples of other emulsifiers include other anionic emulsifiers, cationic emulsifiers, nonionic emulsifiers and the like, and are preferably nonionic emulsifiers.

Other anionic emulsifiers include, for example, fatty acid emulsifiers such as myristic acid, palmitic acid, oleic acid, and linolenic acid ;; alkylbenzene sulfonic acid emulsifiers such as sodium dodecylbenzene sulfonate; and sulfate ester emulsifiers such as sodium lauryl sulfate. And so on.

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

Examples of the nonionic emulsifier include polyoxyalkylene fatty acid esters such as polyoxyethylene stearic acid ester; polyoxyalkylene alkyl ethers such as polyoxyethylene dodecyl ether; polyoxyalkylene alkyl phenol ethers such as polyoxyethylene nonylphenyl ether; and poly. Examples thereof include oxyethylene sorbitan alkyl ester, and polyoxyalkylene alkyl ether and polyoxyalkylene alkyl phenol ether are preferable, and polyoxyethylene alkyl ether and polyoxyethylene alkyl phenol ether are more preferable.

Other emulsifiers other than these phosphoric acid-based emulsifiers can be used alone or in combination of two or more, and the amount used thereof is appropriately selected within a range that does not impair the effects of the present invention.

The method of mixing the monomer component, water, and emulsifier may be a conventional method, and examples thereof include a method of stirring the monomer, emulsifier, and water using a stirrer such as a homogenizer or a disc turbine. The amount of water used is usually 1 to 1000 parts by weight, preferably 5 to 500 parts by weight, more preferably 4 to 300 parts by weight, and particularly preferably 15 to 150 parts by weight, based on 100 parts by weight of the monomer component. Most preferably, it is in the range of 20 to 80 parts by weight.

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, disuccinic acid 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 azobisisobutyronitrile, 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis [2- (2-imidazolin-2-yl) propane, 2, 2'-azobis (propan-2-carboamidine), 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropaneamide], 2,2'-azobis {2- [1- (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 can be mentioned.

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 part 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 cuprous naphthenate, and among these, ferrous sulfate is preferable. Each of 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; erythorbic acid, sodium erythorbicate, erythorbin. Elysorbic acid such as potassium acid or a salt thereof; sulphinate such as sodium hydroxymethane sulfite; sodium sulfite, potassium sulfite, sodium hydrogen sulfite, aldehyde sodium bisulfite, potassium hydrogen sulfite sulfite; sodium pyrosulfite, potassium pyrosulfite Pyro sulfites such as sodium bisulfite and potassium hydrogen pyrosulfite; thiosulfates such as sodium thiosulfite and potassium thiosulfite; of sodium bisulfite, sodium bisulfite, potassium bisulfite, sodium hydrogen phosphite, potassium hydrogen phosphite Pyrophosphoric acid or a salt thereof; pyroaphosphate or a salt thereof such as pyrophosphate, sodium pyrophosphate, potassium pyrophosphate, sodium bisulfite, potassium hydrogenpyrophosphate and the like; 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. It is in the range of ~ 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 preferable combination of the metal ion compound in the reduced state and the other reducing agent is a combination of ferrous sulfate and ascorbic acid or a salt thereof and / or sodium formaldehyde sulfoxylate, and more preferably ferrous sulfate. A combination of ascorbate and / or sodium formaldehyde sulfoxylate, most preferably a combination of ferrous sulfate and alcorbate. The amount of ferrous sulfate used at this time is usually 0.000001 to 0.01 parts by weight, preferably 0.00001 to 0.001 parts by weight, and more preferably 0, based on 100 parts by weight of the monomer component. In the range of 0.0005 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, preferably 0.001 to 1 part by weight, based on 100 parts by weight of the monomer component. Is 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 emulsification of the monomer component, but is usually 10 to 1000 parts by weight, preferably 50 to 1000 parts by weight, based on 100 parts by weight of the monomer component used for the polymerization. It is adjusted to be in the range of 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 method may be 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 usually 80% by weight or more, preferably 90% by weight or more, more preferably 95% by weight or more, and the acrylic rubber bale produced at this time has strength characteristics. It is excellent and has no monomeric odor and is suitable. A polymerization inhibitor may be used to terminate the polymerization.

(Coagulation process)
The coagulation step in the method for producing an acrylic rubber veil of the present invention is characterized in that the emulsion polymerization solution obtained in the above emulsion polymerization step is brought into contact with a magnesium salt aqueous solution as a coagulant to form a hydrous crumb.

The solid content concentration of the emulsion polymerization solution used at the time of coagulation 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. ..

The magnesium salt used as a coagulant is not particularly limited, and examples thereof include inorganic magnesium salts such as magnesium chloride, magnesium nitrate and magnesium sulfate, and organic magnesium salts such as magnesium formate and magnesium acetate. Of these, an inorganic magnesium salt is preferable, and magnesium sulfate is particularly preferable.

Each of these magnesium salts 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 magnesium salt is in this range, the acrylic rubber can be sufficiently solidified, and the compression-resistant permanent strain resistance and water resistance when the acrylic rubber is crosslinked can be highly improved, which is preferable. In the present invention, a coagulant other than the magnesium salt may be used in combination as long as the effect of the present invention is not impaired.

When the magnesium salt concentration of the magnesium salt aqueous solution used is usually in the range of 0.1 to 20% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight, of the hydrous crumb produced. It is suitable because the particle size can be focused uniformly in a specific region.

The temperature of the magnesium salt aqueous solution used is not particularly limited, but is preferably 40 ° C. or higher, preferably 40 to 90 ° C., and more preferably 50 to 80 ° C. to generate a uniform hydrous crumb. ..

The method of contacting the emulsion polymerization solution with the magnesium salt aqueous solution is not particularly limited, but for example, a method of adding the emulsion polymerization solution to the stirred magnesium salt aqueous solution, or a method of adding the emulsion polymerization solution to the stirred emulsion polymerization solution. Examples thereof include a method of adding an aqueous solution, but the shape and crumb diameter of the hydrous crumb generated by the method of adding the emulsion polymerization solution to the stirred magnesium salt aqueous solution can be uniformly and focused in a specific region, and in a later step. It is suitable because it can significantly improve the cleaning efficiency of emulsifiers and coagulants.

The stirring speed (rotation speed) of the magnesium salt aqueous solution being stirred, that is, the rotation speed of the stirring blade of the stirring device is not particularly limited, but is usually 100 rpm or more, preferably 200 to 1000 rpm, and more preferably 300 to. It is in the range of 900 rpm, particularly preferably 350 to 850 rpm, and most preferably 400 to 800 rpm.

It is preferable that the rotation speed is a rotation speed in which the mixture is vigorously stirred to a certain degree so that the generated hydrous crumb particle size can be made small and uniform. By setting the rotation speed to the above lower limit or more, the crumb particle size becomes excessive. It is possible to suppress the formation of large and small ones, and by setting the amount to the above upper limit or less, the coagulation reaction can be more easily controlled.

The peripheral speed of the magnesium salt aqueous solution being stirred is, that is, the speed of the outer circumference of the stirring blade of the stirring device, and although there is no particular limitation, the water-containing crumb particle size generated is smaller when the magnesium salt aqueous solution is vigorously stirred to a certain degree. Moreover, it can be made uniform and is preferable, 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. .. On the other hand, the upper limit of the peripheral speed is not particularly limited, but usually solidifies 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.

By setting the above conditions for the coagulation reaction in the coagulation step (contact method, solid content concentration of emulsion polymerization solution, concentration and temperature of magnesium salt aqueous solution, rotation speed and peripheral speed of magnesium salt aqueous solution during stirring, etc.) within a specific range. The shape and diameter of the hydrous crumb to be produced are uniform and focused, and the removal of emulsifiers and coagulants during washing and dehydration is remarkably improved, which is preferable.

The hydrous crumb thus produced preferably satisfies all of the following conditions (a) to (e). The JIS sieve complies with the provisions of 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.
(B) 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 crumbs that pass through a 6.7 mm mesh JIS sieve and do not pass through a 710 μm JIS sieve is 20% by weight or more.
(D) 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 water-containing crumbs (a) that does not pass through the JIS sieve having a mesh size of 9.5 mm in the generated water-containing crumbs is 10% by weight or less, preferably 5% by weight or less, and more preferably 1% by weight or less. It is suitable because it can significantly improve the cleaning efficiency of emulsifiers and coagulants.

The proportion of the water-containing crumbs (b) that passed through the 9.5 mm mesh JIS sieve and did not pass through the 6.7 mm JIS sieve in the generated hydrous crumbs 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 and the coagulant can be remarkably improved, which is preferable.

The proportion of the water-containing crumb in the generated water-containing crumb that (c) passes through the 6.7 mm mesh JIS sieve and does not pass through the 710 μm JIS sieve is 20% by weight or more, preferably 40% by weight or more, more preferably 70. When it is 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 water-containing crumb in the generated water-containing crumb that passed through the (d) 710 μm-opening JIS sieve and did not pass through the 425 μm JIS sieve was 30% by weight or less, preferably 20% by weight or less, more preferably 15% by weight. When the following, 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 having an opening of 425 μm (e) in the produced hydrous crumb is 10% by weight or less, preferably 5% by weight or less, and more preferably 1% by weight or less, the emulsifier or the like. The cleaning efficiency of the coagulant is remarkably improved, and the productivity is high, which is suitable.

In the present invention, the proportion of the water-containing crumb in the generated water-containing crumb that passes through the (f) JIS sieve having a mesh size of 6.7 mm and does not pass through the JIS sieve having a mesh size of 4.75 mm is particularly limited. However, when it is usually 40% by weight or less, preferably 10% by weight or less, 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 in the produced water-containing crumb that passes through the (g) JIS sieve with a mesh size of 4.75 mm and does not pass through the JIS sieve with a mesh size of 710 μm is not particularly limited. However, when it is usually 40% by weight or more, preferably 60% by weight or more, and more preferably 80% by weight or more, the removal efficiency of the emulsifier and coagulant during cleaning and dehydration is remarkably improved, which is preferable.

Further, in the present invention, the proportion of the water-containing crumb in the generated water-containing crumb that passes through the (h) JIS sieve having a 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. However, 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, washing and dehydration of the emulsifier and coagulant. It is suitable because the removal efficiency at the time is remarkably improved.

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

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 water.

The amount of water used in the washing step 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. More preferably, the amount of ash in the acrylic rubber can be effectively reduced in the range of 100 to 10,000 parts by weight, particularly preferably 150 to 5,000 parts by weight, which is preferable.

The temperature of the water used in the cleaning step is not particularly limited, but it is preferable that the cleaning efficiency is improved when warm water is used. The temperature of the hot water is not particularly limited, but is preferably 40 ° C. or higher, preferably 40 to 100 ° C., more preferably 50 to 90 ° C., and most preferably 60 to 80 ° C., because the cleaning efficiency can be significantly increased. Is.

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 (washing with water) 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 times of washing with water is large, but as described above, the shape of the water-containing crumb and the diameter of the water-containing crumb are set within a specific range. By setting the cleaning temperature within the above range, the number of cleanings can be significantly reduced.

(Dehydration process)
In the present invention, it is preferable to provide a dehydration step with a dehydrator before subjecting the water-containing crumb after washing to the drying step, and to supply the water-containing crumb having a reduced water content in the dehydration step to the drying step. .. In a dehydration step suitable to be carried out in the present invention, the washed hydrous crumb is dehydrated by a dehydrator having a dehydration slit.

In the present invention, the water-containing crumb to be applied to the dehydrator 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 in the range of 50-60% 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 use of a screw type extruder reduces the water content of a water-containing crumb. It is suitable because it can be lowered to a high degree. Adhesive acrylic rubber adheres to the wall surface and slits in a centrifuge and can usually be dehydrated only to about 45 to 55% by weight, and water is forcibly squeezed out like a screw type extruder. A 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 1.0 mm, preferably 0.2 to 0.6 mm, the efficiency of removing coagulants and emulsifiers from the hydrous crumbs. And productivity are highly balanced and suitable.

The water content of the hydrous crumb after dehydration 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 above-mentioned lower limit, the dehydration time can be shortened, deterioration of acrylic rubber can be suppressed, and by making it equal to or lower than the above-mentioned 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 washed water-containing crumb, preferably the water-containing crumb dehydrated after washing with a screw extruder to obtain a dried rubber having a water content of less than 1% by weight. ..

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

(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. Further, it is preferable to carry out a bale step after that. The embodiment is shown below.

Dehydration / drying in a dehydration barrel Dehydration of a hydrous crumb is performed in a dehydration barrel having a dehydration slit. 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, it is suitable because the hydrous crumb can be efficiently dehydrated.

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 vapor (exhaust vapor). In the present invention, the drainage is dehydrated. Exhaust steam is defined as pre-drying to distinguish it.

When using a screw type extruder equipped with multiple dehydration barrels, it is preferable to combine drainage (dehydration) and exhaust steam (pre-drying) because dehydration of the adhesive acrylic rubber and reduction of water content can be performed efficiently. Is. In a screw type extruder equipped with three or more dehydration barrels, the selection of whether each dehydration barrel is a drainage type dehydration barrel or a exhaust steam type dehydration barrel may be appropriately performed according to the purpose of use, but is usually manufactured. To reduce the amount of ash in the acrylic rubber, increase the number of drainage barrels. For example, if there are 3 dehydration barrels, 2 drainage barrels, if there are 4 dehydration barrels, 3 drainage barrels, etc. And select as appropriate.

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 for dehydrating 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 for which pre-drying is performed 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 water-containing crumb after dehydration, that is, the water content after passing through the drainage barrel is not particularly limited, but is usually 1 to 50% by weight, preferably 1 to 40% by weight, and more preferably 10 to 40% by weight. Particularly preferably, it is carried out up to 15 to 35% by weight because the ash content and the water content can be efficiently reduced.

When dehydration of adhesive acrylic rubber is performed using a centrifuge or the like, the acrylic rubber adheres to the dehydration slit portion and can hardly be dehydrated (the water content is reduced only to about 45 to 55% by weight). In the present invention, it is preferable to use a screw type centrifuge having a dehydration slit and a dehydration barrel forcibly squeezed by a screw because the water content can be efficiently reduced to less than that.

The water content of the water-containing crumb that has been pre-dried in the exhaust steam type dehydration barrel after the dehydration is usually 1 to 30% by weight, preferably 3 to 20% by weight, and more preferably 5 to 15% by weight.

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

The degree of decompression inside 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 acrylic rubber gel can be reduced.

The number of drying barrels in the screw type extruder is not particularly limited, but is usually a plurality, preferably 2 to 10 barrels, and more preferably 3 to 8 barrels. When a plurality of dry barrels are provided, the degree of decompression may be an approximate degree of decompression for all the dry barrels, or may be changed. When having a plurality of 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.

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 a screwless rectifying die portion provided near the tip portion of the screw type extruder. A breaker plate or wire mesh may or may not be provided between the screw portion and the die portion.

Acrylic rubber extruded from the die part of the screw type extruder can be obtained in various shapes such as granular, columnar, round bar, and sheet depending on the nozzle shape of the die. The die shape is made substantially rectangular and the sheet is formed. By extruding into a rectangular shape, dry rubber with less air entrainment, low specific gravity, and excellent storage stability can be obtained, which is preferable.

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 (the specific gravity is large). Moreover, it is suitable because it is excellent in productivity.

Operating conditions of the screw type extruder The screw length (L) of the screw type extruder to be 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. 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 lowering the molecular weight of the dried rubber or causing discoloration.

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 1,200 kg / hr, more preferably 400 to 1,000 kg / hr. Most preferably, it is in the range of 500 to 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-making step The bale-making step after the dehydration and drying steps by the screw type extruder is a step of bale-forming the extruded dried rubber. 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 of the baler may be 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 temperature is not particularly limited, but is usually in the range of 10 to 80 ° C, preferably 20 to 60 ° C, and more preferably 30 to 60 ° C. The compression time may be appropriately selected depending on the intended use, but is usually in the range of 1 to 100 seconds, preferably 2 to 60 seconds, and more preferably 5 to 40 seconds.

In the present invention, the sheet-shaped dried rubber can be extruded from the screw type extruder in the dehydration and drying steps, cut if necessary, and laminated to form a veil. 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. It is suitable because it has excellent workability and productivity at some time. In particular, since the thermal conductivity of the sheet-shaped dry rubber is as low as 0.15 to 0.35 W / mK, the thickness of the sheet-shaped dry rubber is usually 1 to 30 mm when the cooling efficiency is increased and the productivity is remarkably improved. The range is 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 according to the purpose of use, but is usually in the range of 300 to 1,200 mm, preferably 400 to 1,000 mm, and more preferably 500 to 800 mm. is there.

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 1,500 to 6,000 Pa · s, preferably 2. Extrudability and shape retention as a sheet when it is in the range of 5,000 to 5,000 Pa · s, more preferably 2,500 to 4,000 Pa · s, and most preferably 2,500 to 3,500 Pa · s. Is highly balanced and suitable. That is, by setting the value of the complex viscosity ([η] 100 ° C.) at 100 ° C. to the lower limit or higher, the extrudability can be improved, and by setting the value to the upper limit or lower, the shape of the sheet-shaped dried rubber can be improved. It can suppress collapse and breakage.

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 for continuous cutting without entraining air. It is preferable to cool it down.

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 2,000 to 10,000 Pa · s. When it is preferably in the range of 2,500 to 7,000 Pa · s, most preferably 2,700 to 5,500 Pa · s, it is preferable that it can be cut continuously without entraining air.

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.) of the sheet-shaped dried rubber is Although there is no particular limitation, it is usually 0.5 or more, preferably 0.6 to 0.98, more preferably 0.7 to 0.96, particularly preferably 0.8 to 0.95, and most preferably 0.83. When the range is in the range of ~ 0.93, the air entrainment property is low, and cutting and productivity are highly balanced, which is preferable.

The method for cooling the sheet-shaped dry rubber is not particularly limited and may be left at room temperature. However, since the thermal conductivity of the sheet-shaped dry 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 in which water is sprayed, or an immersion method in which water is immersed is preferable in order to increase productivity, and an air cooling method in which air is blown or cooled 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 escape. The number of laminated layers may be appropriately selected according to the size or weight of the acrylic rubber veil.

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 content of the acrylic rubber veil of the present invention in the rubber mixture may be selected according to the intended use, for example, usually 10% by weight or more, preferably 20% by weight or more, more preferably 30% by weight or more, particularly. It is preferably 40% by weight or more, and most preferably 50% by weight or more.

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 oxide, 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 application of the reactive group contained in the acrylic rubber constituting the acrylic rubber bale, but is not particularly limited as long as it can cross-link the acrylic rubber bale. , For example, polyvalent amine compounds such as diamine compounds, and carbonates thereof; sulfur compounds; sulfur donors; triazinethiol compounds; polyvalent epoxy compounds; ammonium organic carboxylates; organic peroxides; polyvalent carboxylic acids; Conventionally known cross-linking agents such as a secondary onium salt; an imidazole compound; an isocyanuric acid compound; an organic peroxide; and a 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 benzoate. 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. -Phenylenediamine, m-Phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-(m-Phenylenediisopropyridene) dianiline, 4,4'-(p-phenylenedi) Isopropylidene) 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 an epoxy group-containing acrylic rubber, the cross-linking agent is an aliphatic polyvalent amine compound such as hexamethylenediamine or hexamethylenediamine carbamate, and a carbonate thereof; 4,4'-methylene. 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 carboxylic acid 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 to 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 above 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 crumb shape, a sheet shape, a veil shape, or the like.

These other rubber components can be used alone or in combination of two or more. Further, 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 can be blended with an anti-aging agent, if necessary. The type of 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) , 2,6-di-t-butyl-4- (4,6-bis (octylthio) -1,3,5-triazine-2-ylamino) Phenolic anti-aging agents such as phenol; tris (nonylphenyl) phos Phenolic acid ester anti-aging agents such as phyto, diphenylisodecylphosphite, tetraphenyldipropylene glycol diphosphite; sulfur ester anti-aging agents such as dilauryl thiodipropionate; , 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 condensates; 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. Of these, amine-based anti-aging agents are particularly preferable.

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 antiaging agent. The rubber mixture of the present invention further comprises other additives commonly used in the art, such as cross-linking aids, cross-linking accelerators, cross-linking retarders, silane coupling agents, plasticizers, processing aids, as required. Agents, lubricants, pigments, colorants, antistatic agents, foaming agents and the like can be arbitrarily blended. 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>
As a method for producing the rubber mixture of the present invention, a method of mixing the acrylic rubber veil of the present invention with a filler, a cross-linking agent and the above-mentioned other rubber components, an antiaging agent and other compounding agents which can be contained if necessary is used. Any means used in the conventional rubber processing field, such as an open roll, a Banbury mixer, and various kneaders, can be used for mixing. 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 step and then mix the cross-linking agent in the second step. Other rubber components and anti-aging agents are usually mixed in the first stage, the cross-linking accelerator may be selected in the second stage, and other compounding agents 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 crosslinked 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 or a roll, and then heated to carry out a cross-linking reaction. It can be manufactured by 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.

The rubber crosslinked product of the present invention may be further heated for secondary cross-linking depending on the shape and size of the rubber cross-linked product. 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 crosslinked rubber product of the present invention has excellent compression-resistant permanent strain resistance and water resistance while maintaining basic properties such as tensile strength, elongation, and hardness as rubber.

The rubber crosslinked product of the present invention makes use of the above characteristics, for example, O-ring, packing, diaphragm, oil seal, shaft seal, bearing sheath, mechanical seal, well head seal, seal for electric / electronic equipment, air compression equipment. Sealing materials such as seals for seals; rocker cover gaskets attached to the connection between the cylinder block and the cylinder head, oil pan gaskets attached to the connection between the oil pan and the cylinder head or the transmission case, positive electrode, electrolyte plate and negative electrode. Various gaskets such as gaskets for fuel cell separators and gaskets for top covers of hard disk drives mounted between a pair of housings that sandwich a unit cell equipped with; cushioning material, anti-vibration material; wire coating material; industrial belts; tubes -Preferably used as hoses; sheets; etc.

The rubber cross-linked product of the present invention is also used as an extruded molded product and a molded cross-linked product for automobile applications, for example, fuel oil around a fuel tank such as a fuel hose, a filler neck hose, a vent hose, a paper hose, and an oil hose. 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 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 produced by bringing the emulsion polymerization solution obtained by the emulsion polymerization reactor into contact with an aqueous magnesium salt solution as a coagulant and coagulating it.

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

The heating unit 31 of the coagulation device 3 is configured to heat the magnesium salt aqueous solution 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 magnesium salt aqueous solution 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 coagulation device 3 is configured to stir the magnesium salt aqueous solution 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 magnesium salt aqueous solution by rotating around the rotation axis by the rotational power of the motor 32 in the magnesium salt aqueous solution 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 solidifying 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 performed by the drive control unit so that the stirring number of the magnesium salt aqueous solution is usually in the range of 100 rpm or more, preferably 200 to 1000 rpm, more preferably 300 to 900 rpm, and particularly preferably 400 to 800 rpm. Be controlled. The peripheral speed of the magnesium salt-containing aqueous solution 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. As described above, the rotation of the stirring blade 33 is controlled by the drive control unit. Further, the drive control unit so that the upper limit of the peripheral speed of the magnesium salt-containing aqueous solution 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. Controls the rotation of the stirring blade 33.

The cleaning device 4 shown in FIG. 1 is configured to perform the processing related to the cleaning step described above. 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.

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 conveyed 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. A hot air dryer, a vacuum dryer, an expander dryer, a kneader type dryer, or the like may be used as the dryer.

The screw type extruder 5 is configured to mold the dried rubber obtained through the dehydration step and the drying step into a predetermined shape and discharge it. 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 biaxial 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 water-containing crumb to be dried is not limited to the mode shown in FIG. The number can be set according to the water content and the like.

For example, the number of supply barrels installed in the supply barrel portion 52 is, for example, 1 to 3. 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 dry barrels installed in the dry 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 of the barrel portions 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 usage conditions, and are usually 0.01 to 5 mm, so that the water-containing crumbs are less damaged and the water-containing crumbs have little loss. 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.

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. 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, for example, drainage may be performed by three dehydration barrels on the upstream side, and steam may be 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 the 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 dried 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 that passes 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 the rotation of a pair of screws in the barrel unit 51. The hydrous crumb sent to the dry barrel portion 54 is plasticized and 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.

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, which can efficiently reduce the water content and gel amount of the acrylic rubber. Therefore, 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 watering 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 the sheet-shaped dry rubber 10 discharged from the discharge port of the die 59 of the screw type extruder 5 by an air cooling method while transporting the sheet-shaped dry rubber 10. By using this transport 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 sends 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 (length of the portion where the cooling air can be blown) L1 of the conveyor 61 and the cooling means 65 of the transport type cooling device 60 is not particularly limited, but is, for example, 10 to 100 m, preferably 20 to 50 m. .. Further, 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. 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 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 parallelepiped shape of about 20 kg is produced.

The bale device 7 may include, for example, a baler, and may manufacture 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, for example, 30 ° C. or higher, preferably 40 ° C. or higher. By laminating the cut sheet-shaped dry rubber 16 at 30 ° C. or higher, preferably 40 ° C. or higher, good air bleeding 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, Comparative Examples and Reference Examples. In addition, "part", "%" and "ratio" in each example are weight-based unless otherwise specified. Various characteristics were evaluated according to the following method.

[Monomer composition]
Regarding the monomer composition in acrylic rubber, the monomer composition of each monomer unit in acrylic rubber was confirmed by 1 H-NMR, and the activity of the reactive group 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, since 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, the content ratio of each monomer unit was set to a single amount. It was the same as the amount used by the body.

[Reactive group content]
The content of the reactive group of the acrylic rubber was measured as the content in the acrylic rubber veil 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 an acrylic rubber veil in methyl ethyl ketone, adding a specified amount of hydrochloric acid to the mixture 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.

[Molecular weight and molecular weight distribution]
The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn and Mz / Mw) of the acrylic rubber constituting the acrylic rubber veil are as follows: dimethylformamide, 0.05 mol / L of lithium chloride, and 0. It is an absolute molecular weight and an absolute molecular weight distribution measured by the GPC-MALS method using the solutions added at a concentration of 01%, respectively. 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)
Temperature: Column 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.
Injection volume: 0.200 ml

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

[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.

[Water content]
The water content (%) of the acrylic rubber veil was measured according to the JIS K6230-1: Oven A (volatile content measurement) method.

[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 in the difference in the above ash content measurement.

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

[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 viscoelasticity measuring device “Rubber Process Analyzer RPA-2000” (manufactured by Alpha Technology). The measurement was performed to determine the complex viscoelasticity 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 value of (100 ° C.) / η (60 ° C.) was calculated.

[Moony Viscosity (ML1 + 4,100 ° C)]
The Mooney viscosity (ML1 + 4,100 ° C.) of the acrylic rubber veil was measured according to the uncrosslinked rubber physical test method of JIS K6300.

[Evaluation of workability]
Regarding the processability of the rubber sample, the rubber sample was put into a Banbury mixer heated to 50 ° C. and kneaded for 1 minute, and then the compounding agent A containing the rubber mixture shown in Table 1 was 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 2 as 100 (the smaller the index, the better the workability).

[Storing stability evaluation]
For the storage stability of the rubber sample, the rubber sample was placed in a constant temperature and humidity chamber (SH-222 manufactured by ESPEC) at 45 ° C. × 80% RH, and the rate of change in water content before and after the test for 7 days was calculated and compared. Evaluation was performed using an index with 2 as 100 (the smaller the index, the better the storage stability).

[Water resistance evaluation]
The water resistance of the rubber sample was 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 for a dipping test, and calculating the volume change rate before and after dipping according to the following formula. Comparative Example 2 was evaluated with an index of 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 properties 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 ⊚ for 10 MPa or more and × for 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%.

[Example 1]
In a mixing container equipped with a homomixer, 46 parts of pure water, 48.25 parts of ethyl acrylate as a monomer component, 50 parts of n-butyl acrylate and 1.75 parts of mono-n-butyl fumarate, and octyloxy as an emulsifier. 1.8 parts of dioxyethylene phosphate sodium salt was charged and stirred to obtain a monomer emulsion.

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 balance 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 tank 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 carry out the polymerization reaction. It was stopped to obtain an emulsion polymerization solution.

Next, in a coagulation tank equipped with a thermometer and a stirrer, the mixture was heated to 80 ° C. and vigorously stirred at a stirring blade rotation speed of 600 rpm (peripheral speed 3.1 m / s) of the stirrer. The obtained emulsion polymer solution was heated to 80 ° C. and continuously added to coagulate the polymer in 350 parts (coagulation solution using magnesium sulfate as an agent) to coagulate the solidified acrylic rubber crumb. A solidified slurry containing water was obtained. Moisture was discharged from the solidified layer while filtering the crumbs from the obtained slurry to obtain a hydrous crumb.

194 parts of warm water (70 ° C.) was added to the coagulation tank in which the filtered hydrous crumbs remained, and the mixture was stirred for 15 minutes to wash the hydrous crumbs, and then water was discharged, and 194 parts of warm water (70 ° C.) was discharged again. Was added and stirred for 15 minutes to wash the hydrous crumb (total number of washings was 2). The water-containing crumb (cramm temperature 60 ° C.) after cleaning was supplied to a screw type extruder, dehydrated, dried and molded to extrude a sheet-shaped dry rubber having a width of 300 mm and a thickness of 10 mm. Next, the sheet-shaped dry rubber was cooled at a cooling temperature of 200 ° C./hr by 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 dehydration barrel drains water, and the second and third dehydration barrels drain steam. The operating conditions of the screw type extruder are as follows.

Moisture content ・ Moisture content of the water content crumb after drainage in the first dehydration barrel: 30%
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 supply barrel: 65 ° C
・ Temperature of rubber discharged from screw type extruder: 140 ℃

Set temperature of each barrel:
-First dehydration barrel: 100 ° C
-Second dehydration barrel: 120 ° 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): 132 mm
-Overall length (L) of the screw: 4620 mm
・ L / D: 35
・ Screw rotation speed: 135 rpm
-Rubber extrusion amount from die: 700 kg / hr
-Resin pressure on the die: 2 MPa

Sheet-shaped dry rubber extruded from a screw-type extruder is cooled to 50 ° C, cut to a length of 650 mm with a cutter, and laminated to 20 parts (20 kg) before the temperature drops below 40 ° C. An acrylic rubber veil (A) was obtained. Reactive group content, ash content, ash component content, specific gravity, gel amount, pH, glass transition temperature (Tg), water content, molecular weight, molecular weight distribution, complex viscosity, and the obtained acrylic rubber bale (A). The Mooney viscosity (ML1 + 4,100 ° C.) was measured and shown in Table 2. In addition, the storage stability test of the acrylic rubber veil (A) was performed to determine the rate of change in water content, and the results are shown in Table 2.
Next, 100 parts of the acrylic rubber bale (A) and the compounding agent A of "formulation 1" shown in Table 1 were put into a Banbury mixer and mixed at 50 ° C. for 5 minutes (first stage mixing). The BIT at this time was measured to evaluate the processability of the acrylic rubber bale, and the results are shown in Table 2.
Further, each of the mixtures obtained in the first-stage mixing was transferred to a roll at 50 ° C., and the compounding agent B of "Formulation 1" was mixed and mixed (second-stage mixing) to obtain a rubber mixture.

The rubber mixture thus obtained 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 the obtained primary crosslink was obtained. The material was further heated in a gear oven at 180 ° C. for 2 hours for secondary cross-linking to obtain a sheet-shaped rubber cross-linked product. Then, a 3 cm × 2 cm × 0.2 cm test piece was cut out from the obtained sheet-shaped rubber crosslinked product to evaluate the water resistance and normal physical characteristics, and the results are shown in Table 2.

[Example 2]
The monomer component was ethyl acrylate (28 parts), n-butyl acrylate (38 parts), methoxyethyl acrylate (27 parts), acrylonitrile (5 parts) and allyl glycidyl ether (2 parts), and the emulsifier was nonylphenylhexaoxyethylene phosphate sodium salt. Acrylic rubber veil (B) was obtained and each characteristic (however, the compounding agent was changed to "formulation 2") was evaluated in the same manner as in Example 1 except for the change. The results are shown in Table 2.

[Example 3]
The monomer component was 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, and the emulsifier was tridecyloxyhexaoxy. Acrylic rubber veil (C) was obtained and each characteristic (however, the compounding agent was changed to "formulation 3") was evaluated in the same manner as in Example 1 except that the sodium salt was changed to ethylene phosphate ester. The results are shown in Table 2.

[Example 4]
The temperature of the first dehydration barrel is changed to 90 ° C. and the temperature of the second dehydration barrel is changed to 100 ° C. so that drainage is performed in the first and second dehydration barrels, and after drainage in the second dehydration barrel. Acrylic rubber barrel (D) was obtained in the same manner as in Example 1 except that the water content of the water-containing crumb was changed to 20%, and each characteristic was evaluated. The results are shown in Table 2.

[Example 5]
The monomer component is 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 is nonylphenyloxyhexa. Acrylic rubber veil (E) was produced in the same manner as in Example 4 except that it was changed to an oxyethylene phosphate sodium salt, and each characteristic (however, the compounding agent was changed to “formulation 4”) was evaluated. The results are shown in Table 2.

[Example 6]
The monomer component is 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 the emulsifier is tridecyloxyhexaoxyethylene phosphate. Acrylic rubber veil (F) was produced in the same manner as in Example 5 except that it was changed to an ester sodium salt, and each characteristic was evaluated. The results are shown in Table 2.

[Comparative Example 1]
The emulsion polymer solution obtained by emulsion polymerization in the same manner as in Example 3 is stirred (100 rpm, peripheral speed 0.5 m / s), and a coagulation reaction is carried out by adding a 0.7% magnesium sulfate aqueous solution at 80 ° C. to this. The hydrous crumb was generated by stirring the produced hydrous crumb with 194 parts of warm water (70 ° C.) for 15 minutes, and the operation was repeated again, and then dried in a hot air dryer at 160 ° C. to obtain the water content. 0.4% by weight of crumb-shaped acrylic rubber (G) was obtained, each characteristic was evaluated in the same manner as in Example 3, and the results are shown in Table 2.

[Comparative Example 2]
The emulsifier was changed to 0.709 parts of sodium lauryl sulfate and 1.82 parts of polyoxyethylene dodecyl ether (molecular weight 1500), the coagulation solution was changed to 0.7% aqueous sodium sulfate solution, and the washing method was a coagulation reaction. To 100 parts of the subsequent hydrous crumb, 194 parts of industrial water was added, and the mixture was stirred in the coagulation tank at 25 ° C. for 5 minutes, and then the hydrous crumb for discharging water from the coagulation tank was washed 4 times, and then at pH 3. After adding 194 parts of an aqueous sulfuric acid solution and stirring at 25 ° C. for 5 minutes, water is discharged from the coagulation tank to perform acid cleaning once, and then 194 parts of pure water is added to perform pure water cleaning once. Except for the change, the same procedure as in Comparative Example 1 was carried out to obtain a crumb-shaped acrylic rubber (H) and evaluate each characteristic. The results are shown in Table 2.

From Table 2, it has a reactive group, the ash content is 0.6% by weight or less, the total amount of magnesium and phosphorus in the ash content is 30% by weight or more as a ratio to the total ash content, and the gel amount of the methyl ethyl ketone insoluble content. The acrylic rubber veils (A) to (F) of the present invention having a content of 50% by weight or less are remarkably excellent in processability and water resistance, and are also excellent in normal physical properties such as storage stability and strength characteristics. Understand (comparison between Examples 1 to 6 and Comparative Examples 1 to 3).

From Table 2, the amount of ash is determined by using a divalent phosphoric acid-based emulsifier and divalent magnesium as compared with the crumb-like acrylic rubber (H) which was coagulated with a monovalent sodium salt using a sulfuric acid-based emulsifier and washed and dried. It can be seen that the amount of crumb-shaped acrylic rubber (G) solidified with salt, washed and dried is overwhelmingly large (comparison between Comparative Examples 1 and 2).

However, by specifying the coagulant concentration and addition method in the coagulation step, the rotation speed and peripheral speed of the coagulation liquid, and by performing dehydration and squeezing out the components that become ash together with water from the water-containing crumb, the acrylic rubber bale (A) It can be seen that the amount of ash in (F) could be reduced (comparison between Examples 1 to 6 and Comparative Example 1). Further, the ash content of the acrylic rubber veils (A) to (F) is reduced to only about 1/2 to 1/3 of the ash content of the crumb-shaped acrylic rubber (H), but the storage stability is 1. It can be seen that both characteristics are overwhelmingly improved, with / 5 to 1/10 and water resistance of 1/10 to 1/50. This gives an overwhelming effect of improving storage stability and water resistance by increasing the ratio of the amount of phosphorus and the amount of magnesium in the ash.

From Table 2, regarding workability, 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 amount of gel increases sharply and the processability of acrylic rubber is improved. Although it was aggravated (Comparative Examples 1 and 2), it was dried in a screw type extruder to a state where there was no water (water content less than 1%) and melt-kneaded, so that the rapidly increased gel disappeared and acrylic It can be seen that the workability and strength of the rubber bale are highly balanced (Examples 1 to 6).

From Table 2, Examples 4 to 6 in which dehydration (drainage) to a water content of 20% was performed compared to Examples 1 to 3 in which dehydration (drainage) to a water content of 30% was performed by a screw type extruder. It can be seen that the amount of residual ash is further reduced, and the water resistance and storage stability are remarkably superior.

From Table 2, the dehydration step of dehydrating the hydrous crumb and the drying step of drying are carried out in a dehydration barrel using a dehydration barrel having a dehydration slit, a drying barrel for drying under reduced pressure, and a screw type extruder having a die at the tip. The acrylic rubber veils (A) to (F) of the present invention obtained by dehydrating to a water content of 1 to 40%, drying to a water content of less than 1% in a drying barrel, and extruding the dried rubber from the die have a large specific gravity. It can be seen that the amount of gel is extremely reduced (the amount of residual air is small), and it is found that the workability is excellent as well as the effects of water resistance and storage stability of the present invention.

From Table 2, further, the reactive group content, ash content, ash component amount, specific gravity, gel amount, pH, glass transition temperature (Tg), water content, weight average molecular weight (Mw), weight average molecular weight (Mw) The ratio of number average molecular weight (Mn) (Mw / Mn), the ratio of z average molecular weight (Mz) to weight average molecular weight (Mw) (Mz / Mw), and the complex viscosity ratio at 100 ° C and 60 ° C and its viscosity ratio. , And acrylic rubber veils (A) to (F) having a Mooney viscosity (ML1 + 4,100 ° C.) in a specific region are overwhelmingly excellent in normal physical properties such as workability, storage stability, water resistance and strength characteristics. Understand (Examples 1 to 6).

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

Claims (29)

It is made of acrylic rubber having a reactive group, the ash content is 0.6% by weight or less, the total amount of magnesium and phosphorus in the ash content is 30% by weight or more as a ratio to the total ash content, and the gel amount of methyl ethyl ketone insoluble content is Acrylic rubber veil of 50% by weight or less. The acrylic rubber veil according to claim 1, 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 claim 1 or 2, wherein the total amount of magnesium and phosphorus in the ash content is 80% by weight or more as a ratio to the total ash content. Any one of claims 1 to 3, wherein the acrylic rubber has at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester. Acrylic rubber veil as described in the section. The acrylic rubber veil according to any one of claims 1 to 4, 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 5, wherein the reactive group content is in the range of 0.001 to 5% by weight. The acrylic rubber veil according to any one of claims 1 to 6, wherein the complex viscosity ([η] 60 ° C.) at 60 ° C. is 15,000 Pa · s or less. 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 7. The acrylic rubber veil according to any one of claims 1 to 8, which has a specific gravity in the range of 0.7 to 1.5. The acrylic rubber veil according to any one of claims 1 to 9, 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 10, wherein the amount of ash is 0.001 to 0.5% by weight. The acrylic rubber veil according to any one of claims 1 to 11, which has a pH of 6 or less. The acrylic rubber veil according to any one of claims 1 to 12, wherein the glass transition temperature (Tg) is 20 ° C. or lower. The acrylic rubber veil according to any one of claims 1 to 13, wherein the Mooney viscosity (ML1 + 4,100 ° C.) is in the range of 10 to 150. A monomer component containing a (meth) acrylic acid ester and a reactive group-containing monomer is emulsionized with water and a phosphoric acid emulsifier, and the monomer is present in the presence of a redox catalyst composed of a radical generator and a reducing agent. An emulsion polymerization step in which components are emulsion-polymerized to obtain an emulsion polymerization solution,
A coagulation step in which the obtained emulsion polymerization solution is brought into contact with an aqueous magnesium salt solution as a coagulant to form a hydrous crumb,
A cleaning process to clean the generated hydrous crumbs,
A dehydration process that dehydrates the washed hydrous crumb with a dehydrator,
A drying step of drying a water-containing crumb whose water content has been reduced in the dehydration step with a screw type extruder to obtain a dried rubber having a water content of less than 1% by weight.
A veiling process for veiling dry rubber with a water content of less than 1% by weight,
Manufacturing method of acrylic rubber veil including. Polymer emulsion contact with aqueous magnesium salt solution is stirred in the aqueous magnesium salt solution and those performed by Rukoto be added polymer emulsion manufacturing method of the acrylic rubber bale according to claim 15. The method for producing an acrylic rubber veil according to claim 16 , wherein the rotation speed of the agitated magnesium salt aqueous solution is 100 rpm or more. The method for producing an acrylic rubber veil according to claim 16 or 17 , wherein the stirring magnesium salt aqueous solution has a peripheral speed of 0.5 m / s or more. The method for producing an acrylic rubber veil according to any one of claims 15 to 18 , wherein the magnesium salt concentration of the magnesium salt aqueous solution is 0.5% by weight or more. The method for producing an acrylic rubber veil according to any one of claims 15 to 19 , wherein the hydrous crumb produced in the solidification step satisfies the following (a) to (e).
(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.
(B) 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 crumbs that pass through a 6.7 mm mesh JIS sieve and do not pass through a 710 μm JIS sieve is 20% by weight or more.
(D) 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. The method for producing an acrylic rubber veil according to any one of claims 15 to 20 , wherein the water-containing crumb is washed with warm water. The method for producing an acrylic rubber veil according to any one of claims 15 to 21 , wherein the water-containing crumb is dehydrated to a water content of 1 to 50% by weight. The dehydration step and the drying step are carried out by using a dehydration barrel having a dehydration slit, a drying barrel for drying under reduced pressure, and a screw type extruder having a die at the tip, and the water content 1 to 1 in the dehydration barrel. The acrylic rubber bale according to any one of claims 15 to 22 , which is obtained by dehydrating to 50% by weight, drying in the drying barrel to a water content of less than 1% by weight, and extruding the dried rubber from the die. Production method. The method for producing an acrylic rubber veil according to any one of claims 15 to 23 , wherein the dry rubber is a sheet-shaped dry rubber. The method for producing an acrylic rubber veil according to any one of claims 15 to 24 , wherein the bale is formed by laminating sheet-shaped dry rubber. 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 14. The method according to acrylic rubber bale according to any one of claim 1 to 14, Lugo arm mixtures be mixed by mixer fillers and crosslinking agents. The method according to acrylic rubber bale according to any one of claim 1 to 14, Lugo arm mixture to mix the crosslinking agent after mixing the filler. A rubber crosslinked product obtained by cross-linking the rubber mixture according to claim 26 .