WO2021246512A1

WO2021246512A1 - Acrylic rubber veil having excellent roll processability and banbury processability

Info

Publication number: WO2021246512A1
Application number: PCT/JP2021/021344
Authority: WO
Inventors: 浩文増田; 孝文川中
Original assignee: 日本ゼオン株式会社
Priority date: 2020-06-05
Filing date: 2021-06-04
Publication date: 2021-12-09
Also published as: KR20230020410A; CN116134058A; JPWO2021246512A1

Abstract

Provided is an acrylic rubber veil having excellent roll processability and Banbury processability. The acrylic rubber veil is made of an acrylic rubber which has at least one reactive group selected from the group consisting of a carboxylic group, an epoxy group, and a chlorine atom, and in which the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) in an absolute molecular weight distribution measured by the GPC-MALS method using a dimethylformamide-based solvent as a developing solvent is at least 3.4, and the amount of methyl ethyl ketone insoluble matter is 50 wt% or less and the amount of ash is 0.4 wt% or less.

Description

Acrylic rubber veil with excellent roll workability and Banbury workability

The present invention relates to an acrylic rubber veil, a method for producing the same, a rubber composition, and a rubber crosslinked product. The present invention relates to an acrylic rubber veil, a method for producing the same, a rubber composition containing the acrylic rubber veil, and a rubber crosslinked product obtained by cross-linking the acrylic rubber veil.

Acrylic rubber is a polymer containing acrylic acid ester as a main component, and is generally known as rubber having excellent heat resistance, oil resistance, and ozone resistance, and is widely used in automobile-related fields and the like.

For example, Patent Document 1 (International Publication No. 2019/188709 pamphlet) is charged with a monomer component composed of ethyl acrylate, butyl acrylate, methoxyethyl acrylate and monobutyl fumarate, water and sodium lauryl sulfate, and the pressure is reduced. After repeated degassing and nitrogen substitution, sodium aldehyde sulfoxylate and cumenhydroperoxide, which is an organic radical generator, are added to start emulsion polymerization at normal pressure and normal temperature, and the polymerization conversion rate becomes 95% by weight. Disclosed is a method of producing acrylic rubber by emulsion polymerization, solidifying with an aqueous solution of calcium chloride, filtering with a wire net, and dehydrating and drying with an extrusion dryer having a screw. However, the acrylic rubber obtained by this method has a problem that the roll processability and the Banbury processability are extremely inferior, and the storage stability and the water resistance are also inferior.

In Patent Document 2 (Japanese Unexamined Patent Publication No. 2019-11977), a monomer component composed of ethyl acrylate, butyl acrylate, methoxyethyl acrylate and monobutyl maleate is used as pure water and an emulsifier as sodium lauryl sulfate and polyoxyethylene. After making a monomer emulsion using dodecyl ether, a part of the monomer emulsion is put into a polymerization reaction tank and cooled to 12 ° C. under a nitrogen stream, and then the rest of the monomer emulsion and sulfuric acid are used. Ferrite, sodium ascorbate, and an aqueous solution of potassium persulfate as an inorganic radical generator were continuously added dropwise over 3 hours, and then the temperature was kept at 23 ° C. and emulsion polymerization was continuously carried out for 1 hour to carry out polymerization conversion. After reaching 97% by weight, the temperature was raised to 85 ° C., and then sodium sulfate was continuously added to obtain a water-containing crumb by coagulation filtration, and the water-containing crumb was washed with water four times, acid-washed once and purely. A method is disclosed in which acrylic rubber is continuously produced in the form of a sheet in an extruder having a screw after washing with water once, and crosslinked with an aliphatic polyvalent amine compound such as hexamethylenediamine carbamate. However, the sheet-shaped acrylic rubber obtained by this method has a problem that the roll processability is inferior and the water resistance of the crosslinked product is inferior. Further, Patent Document 2 does not describe that the obtained sheet-shaped acrylic rubber is veiled.

Patent Document 3 (Japanese Unexamined Patent Publication No. 1-135811) describes a monomer component composed of ethyl acrylate, caprolactone-added acrylic acid ester, cyanoethyl acrylate and vinyl chloroacetate, and n-dodecyl mercaptan as a chain transfer agent. 1/4 amount of the monomer mixture is emulsified with sodium lauryl sulfate, polyethylene glycol nonylphenyl ether and distilled water, and sodium sulfite and ammonium persulfate as an inorganic radical generator are added to initiate polymerization, and the temperature is 60. The remaining monomer mixture and the 2% ammonium persulfate aqueous solution were added dropwise at ° C for 2 hours, and the latex having a polymerization conversion rate of 96 to 99%, in which polymerization was continued for another 2 hours after the addition, was added to the sodium chloride aqueous solution at 80 ° C. A method of producing acrylic rubber by solidifying, washing thoroughly with water, and then drying to produce acrylic rubber and cross-linking with sulfur is disclosed. However, the acrylic rubber obtained by this method has a problem that the roll processability and the storage stability are inferior, and the strength characteristics and the water resistance of the crosslinked product are inferior.

In Patent Document 4 (Japanese Unexamined Patent Publication No. 2018-168343), as a monomer component composed of ethyl acrylate, butyl acrylate and monobutyl fumarate, pure water, sodium lauryl sulfate, polyethylene glycol monostearate and a chain transfer agent. A monomeric emulsion consisting of n-dodecyl mercaptan was prepared, and then a part of the monomeric emulsion and pure water were added to the polymerization reaction tank and cooled to 12 ° C., and then the rest of the monomeric emulsion was cooled. , Ferrous sulfate, sodium ascorbate and potassium persulfate as an inorganic radical generator were continuously added dropwise over 2.5 hours, then kept at 23 ° C. and the reaction was continued for 1 hour, and then industrial water was added at 85 ° C. After raising the temperature, sodium sulfate is continuously added at 85 ° C to solidify to obtain a hydrous crumb, and after washing with pure water three times, it is dried with a hot air dryer to produce acrylic rubber. A method of cross-linking with -bis [4- (4-aminophenoxy) phenyl] propane is disclosed. However, although the acrylic rubber obtained by this method is excellent in stress relaxation property and extrusion processability, it has a problem that the roll processability and storage stability are not sufficient, and the strength characteristics and water resistance of the crosslinked product are inferior.

In Patent Document 5 (Japanese Unexamined Patent Publication No. 9-143229), a monomer mixture composed of ethyl acrylate, special acrylate and monochloroacetate, sodium lauryl sulfate as an emulsifier, n-octyl mercaptan as a chain transfer agent and water are reacted. After addition to the container and substituting with nitrogen, ammonium hydrogen sulfite and sodium persulfate as an inorganic radical generator were added to initiate the polymerization reaction, and the reaction was copolymerized at 55 ° C. for 3 hours at a reaction conversion rate of 93 to 96% to obtain acrylic rubber. A method of manufacturing and cross-linking with sulfur is disclosed. However, the Akuri rubber obtained by this method has a problem that the storage stability is inferior, and the strength characteristics and water resistance of the crosslinked product are inferior.

In Patent Document 6 (Japanese Unexamined Patent Publication No. 62-64809), at least one compound of acrylic acid alkyl ester and acrylic acid alkoxyalkyl ester is 50 to 99.9% by weight, and an unsaturated carboxylic having a radical reactive group. Coweight of a monomer composition consisting of 0.1 to 20% by weight of a dihydrodicyclopentenyl group-containing ester of acid and 0 to 20% by weight of at least one of other monovinyl-based, monovinylidene-based and monovinylene-based unsaturated compounds. The compound has a polystyrene-equivalent number average molecular weight (Mn) of 200,000 to 1.2 million using the tetrahydrofuran as a developing solvent, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / Mn). ) Is 10 or less, and an acrylic rubber having excellent processability, compression set, tensile strength and capable of sulfur sulfurization is disclosed. The number average molecular weight (Mn) is 200,000 to 1,000,000, preferably 200,000 to 1,000,000. If Mn is less than 200,000, the physical properties and processability of the vulcanized product are inferior, and if it exceeds 1.2 million, it is processed. It is described that the properties are inferior and that the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) becomes large when it exceeds 10, which is not preferable. Specific examples thereof include monomer components including ethyl acrylate and radical crosslinkable dihydrodicyclopentenyl acrylate, sodium lauryl sulfate as an emulsifier, potassium persulfate as an inorganic radical generator, and a molecular weight modifier. Octyl thioglycolate and t-dodecyl mercaptan are added in varying amounts, with a number average molecular weight (Mn) of 53-1.15 million, a weight average molecular weight (Mw) of 354 to 6.26 million, and a weight average molecular weight (Mw) and a number average molecular weight. A production method is disclosed in which an acrylic rubber having a ratio (Mw / Mn) of 4.7 to 8 to (Mn) is polymerized, coagulated in an aqueous calcium chloride solution, washed thoroughly with water, and directly dried. When the amount of the chain transfer agent is small, the obtained acrylic rubber has a large number average molecular weight (Mw) of 5 million, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1. When the amount of chain transfer agent is large, the number average molecular weight (Mn) is as small as 200,000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 17 and extremely. It is shown in the comparative examples of Examples that it becomes wider. However, the acrylic rubber obtained by this method is inferior in compression-resistant permanent strain resistance and storage stability, and contains a radical-reactive group, so that an appropriate molecular weight distribution (Mw / Mn) is used in the polymerization reaction using a radical generator. ) Is obtained, but there is also a problem that the molecular weight (Mw, Mn) is too large and complicated, and the roll processability and the Banbury processability are not sufficient. In the cross-linking reaction, the acrylic rubber obtained by this method is subjected to sulfur as a cross-linking agent and a vulcanization accelerator, kneaded with a roll, and then subjected to a 100 kg / cm ² vulcanization press at 170 ° C. for 15 minutes, and further in a gear oven. There is a problem that cross-linking is required for a long time of 4 hours at 175 ° C, and the obtained cross-linked product is also inferior in compression-resistant permanent strain resistance, water resistance and strength characteristics, and also inferior in physical property change after thermal deterioration. was there.

On the other hand, as a method for producing veiled acrylic rubber, for example, Patent Document 7 (Japanese Unexamined Patent Publication No. 2006-328239) describes a crumb containing a crumb-like rubber polymer by contacting a polymer latex with a coagulating liquid. The step of obtaining the slurry, the step of crushing the crumb-shaped rubber polymer contained in the crumb slurry with a mixer with a stirring / crushing function ^{having a stirring power of 1 kW / m 3 or more, and the step of crushing the crumb-shaped rubber polymer.} Disclosed and dried, a method for producing a rubber polymer comprising a dehydration step of removing water from the clam slurry to obtain a crumb-shaped rubber polymer and a step of heating and drying the crumb-shaped rubber polymer from which the water has been removed is disclosed. It is stated that the crumbs are flaked and introduced into the baler to be compressed and veiled. As the rubber polymer used here, an unsaturated nitrile-conjugated diene copolymer latex obtained by emulsification polymerization is specifically shown, and an ethyl acrylate / n-butyl acrylate copolymer and an ethyl acrylate / It has been shown that it can be applied to a 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 properties such as heat resistance and compression set resistance.

As acrylic rubber having an ion-reactive group having excellent heat resistance and compression resistance permanent strain characteristics and being veiled, for example, Patent Document 8 (International Publication No. 2018/116828) describes ethyl acrylate and acrylic acid. A monomer component consisting of n-butyl and mono-butyl fumarate is emulsified with sodium lauryl sulfate as an emulsifier, polyethylene glycol monostearate, and water, and cumenehydroperoxide, which is an organic radical generator, is added. Acrylic rubber latex emulsion-polymerized until the polymerization conversion rate reaches 95% is added to an aqueous solution of magnesium sulfate and a polymer flocculant dimethylamine-ammonia-epichlorohydrin polycondensate, and then stirred at 85 ° C. A method is disclosed in which a crumb slurry is generated, and then the crumb slurry is washed once with water and then passed through a 100-mesh wire net in its entirety to capture only the solid content and recover the crumb-shaped acrylic rubber. 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, with this method, a large number of semi-coagulated water-containing crumbs are generated in the coagulation reaction, and a large amount of water-containing crumbs adhere to the coagulation tank. There was a problem that the roll processability, the emulsifier processability, and the water resistance were inferior, and even if a bale was produced, air could not be sufficiently removed and the storage stability was also inferior.

International Publication No. 2019/188709 Pamphlet Japanese Unexamined Patent Publication No. 2019-11977 Japanese Unexamined Patent Publication No. 1-135811 Japanese Unexamined Patent Publication No. 2018-168343 Japanese Unexamined Patent Publication No. 9-143229 Japanese Unexamined Patent Publication No. 62-64809 Japanese Unexamined Patent Publication No. 2006-328239 International Publication No. 2018/116828 Pamphlet

The present invention has been made in view of the actual conditions of the prior art, and is an acrylic rubber bale having excellent roll workability and Banbury workability, and having a highly balanced water resistance and compression set resistance of crosslinked products. , A method for producing the same, a rubber composition containing the acrylic rubber veil, and a rubber crosslinked product obtained by cross-linking the same.

As a result of diligent research in view of the above problems, the present inventors have a specific reactive group, and the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the absolute molecular weight distribution measured by the GPC-MALS method. ) Is composed of acrylic rubber whose ratio (Mw / Mn) is within a specific range, and the acrylic rubber veil having an insoluble content and an ash content of a specific solvent within a specific range is excellent in roll processability and Banbury processability. Moreover, it has been found that the crosslinked product is highly balanced in water resistance and compression set resistance, and is excellent.

The present inventors have an acrylic rubber veil made of acrylic rubber having a reactive group capable of reacting with a cross-linking agent such as a carboxyl group, an epoxy group, and a chlorine atom, which is excellent in short-time cross-linking property, strength property, and compression set resistance permanent strain property. I found that.

The present inventors also, in the GPC measurement of acrylic rubber having such a reactive group, the tetrahydrofuran used for the GPC measurement of a radically reactive acrylic rubber copolymerized with the above-mentioned prior art ethyl acrylate, dihydrodicyclopentenyl acrylate and the like. However, it was not possible to measure each molecular weight and molecular weight distribution cleanly and with good reproducibility, but by using a specific solvent with a higher SP value than tetrahydrofuran as the developing solvent, it could be dissolved cleanly and measured with good reproducibility. It was found that the roll processability and the solvent processability of the acrylic rubber bale are excellent, and the water resistance and the compression set resistance property of the crosslinked product can be highly balanced by specifying the characteristic value of.

Regarding the roll processability of the acrylic rubber bale, the present inventors have a number average molecular weight (Mn), a weight average molecular weight (Mw), and a number average measured by the GPC-MALS method of the acrylic rubber constituting the acrylic rubber bale. It has been found that the ratio (Mw / Mn) to the molecular weight (Mn) is greatly related, and when each is in a specific range, the roll processability can be remarkably improved without impairing the strength characteristics. In particular, the larger the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn), the better the roll processability. Although it was difficult to produce an acrylic rubber having a wide ratio (Mw / Mn) of the average molecular weight (Mw) to the number average molecular weight (Mn), the present inventors initially added a chain transfer agent. It was found that this can be achieved by adding batches in the middle of polymerization without using it. The present inventors also dried the hydrous crumb produced by the solidification reaction with a high share using a screw type twin-screw extruder to obtain the weight average molecular weight (Mw) without impairing the number average molecular weight (Mn). It was found that the ratio (Mw / Mn) to the number average molecular weight (Mn) was greatly widened and the roll processability was further improved.

The present inventors have found that the smaller the amount of methyl ethyl ketone insoluble in the acrylic rubber veil, the better the Banbury processability. The amount of methyl ethyl ketone insoluble in acrylic rubber veil is generated during the polymerization reaction, and it increases rapidly when the polymerization conversion rate is increased to improve the strength characteristics, and it is difficult to control it. It can be suppressed to some extent by emulsion polymerization in the presence, and the acrylic rubber is melted in a state where the rapidly increased methyl ethyl ketone insoluble content is substantially free of water (water content less than 1% by weight) in the screw type twin-screw extruder. It was found that by kneading and extrusion-drying, the rapidly increased amount of methyl ethyl ketone insoluble matter disappears, there is no variation, and the Banbury processability can be significantly improved without impairing the roll processability of the acrylic rubber veil. The present inventors also have that the acrylic rubber bale produced by melt-extruding with almost all water removed by a screw-type twin-screw extruder has a high balance between Banbury workability and strength characteristics. I found.

The present inventors have also found that the water resistance of the acrylic rubber veil is greatly affected by the amount of ash and the ash component in the acrylic rubber veil. It is difficult to reduce the ash content of acrylic rubber, which uses a large amount of emulsifier and coagulant in emulsion polymerization, but the hydrous crumb produced by coagulation by a specific method has cleaning efficiency in warm water and ash removal by dehydration. It has been found that the efficiency is significantly improved, and as a result, the water resistance of the acrylic rubber veil can be significantly improved. In particular, the present inventors have increased the ratio of the specific particle size of the hydrous crumb generated in the solidification step to perform washing, dehydration, and drying to obtain roll processability, bumper processability, and strength characteristics of the acrylic rubber veil. It was also found that the water resistance can be significantly improved without impairing the properties such as compression resistance and permanent strain resistance. Further, the present inventors have excellent water resistance of the acrylic rubber veil and a mold when a specific emulsifier is used in the emulsion polymerization of acrylic rubber or when a specific coagulant is used when the emulsion polymerization solution is coagulated. It was found that the releasability to the like is significantly enhanced.

The present inventors also have a specific reactive group in the acrylic rubber constituting the acrylic rubber veil, and the ratio of the weight average molecular weight (Mw) or z average molecular weight (Mz) to the weight average molecular weight (Mw). It has been found that when (Mz / Mw) is specific, the normal physical properties including the crosslinkability, the compression resistance permanent strain property and the strength property of the crosslinked product of the acrylic rubber veil are highly balanced.

By increasing the specific gravity of the acrylic rubber bale, the present inventors are excellent in roll workability, Banbury workability, water resistance, strength property and compression set resistance property, and further, storage stability is greatly improved. I found that. Acrylic rubber having a specific reactive group is sticky and difficult to release air, and crumb-shaped acrylic rubber obtained by directly drying a water-containing crumb entrains a large amount of air (the specific gravity becomes small) and deteriorates storage stability. However, by compressing the crumb-shaped acrylic rubber with a baler or the like to make it into a veil, air can be evacuated to some extent and the storage stability can be improved, and the hydrous crumb is extruded under reduced pressure by a screw type twin-screw extruder. It has been found that a veil-shaped acrylic rubber that contains almost no air and has a high specific gravity and significantly improved storage stability can be produced by extruding and laminating in the form of a dry, air-free sheet. The present inventors have also found that the specific gravity including the content of such air can be measured according to the method A of JIS K6268 crosslinked rubber-density measurement using the difference in buoyancy. It was also found that the storage stability of the acrylic rubber veil can be further improved by specifying the pH.

The present inventors also increase the cooling rate after drying to stabilize the Mooney scorch without impairing the roll processability, bumper processability, water resistance, strength characteristics, compression permanent strain resistance, and other characteristics of the acrylic rubber veil. We found that we could significantly improve our sexuality.

The present inventors also emulsify a specific monomer component with water and an emulsifier, and then initiate emulsion polymerization in the presence of a redox catalyst composed of an inorganic radical generator such as potassium persulfate and a reducing agent. Emulsion polymerization is carried out by adding the chain transfer agent in batches during the polymerization without adding it at the initial stage, the obtained emulsion polymerization is coagulated under specific conditions, and the hydrous crumb generated by the coagulation reaction is washed with warm water. By doing so, and by drying and veiling the water-containing crumb after washing, the high-molecular-weight component and low-molecular-weight component of acrylic rubber that can be produced coexist to obtain a wide molecular weight distribution, and the ash content and specific solvent of the specific component. By specifying the amount of insoluble matter, it was found that the roll processability, Banbury processability, strength property, compression permanent strain resistance property and water resistance of the obtained acrylic rubber veil are highly balanced.

The present inventors also melted and kneaded acrylic rubber under a high share condition using a specific extruder dryer, and dried the acrylic rubber veil with further improved roll processability, strength characteristics, and water resistance. Found that it can be manufactured. Furthermore, it has been found that an acrylic rubber veil having a better balance of roll processability, strength characteristics, and water resistance can be produced by adding after the reducing agent and specifying the polymerization temperature.

The present inventors further, in the rubber composition containing the acrylic rubber veil, the filler and the cross-linking agent of the present invention, by blending carbon black or silica as the filler, the roll processability, the Banbury processability and the short time can be achieved. It was found that the crosslinked product is excellent in crosslinkability, and the crosslinked product is highly excellent in water resistance, strength characteristics and compression set resistance. The present inventors also preferably use an organic compound, a polyvalent compound or an ionic cross-linking compound as the cross-linking agent, for example, an ionic reaction of an acrylic rubber veil such as an amine group, an epoxy group, a carboxyl group or a thiol group. Since it is a polyvalent ion organic compound having a plurality of ionic reactive groups that react with a sexual group, it is excellent in roll processability, Banbury processability and short-time crosslinkability, and also has water resistance, strength characteristics and compression resistance of the crosslinked product. We have found that the permanent strain characteristics are highly excellent.

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

Thus, according to the present invention, it has at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom, and has an absolute molecular weight measured by the GPC-MALS method using a dimethylformamide-based solvent as a developing solvent. It is made of acrylic rubber in which the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the distribution is 3.4 or more, and the amount of methyl ethyl ketone insoluble is 50% by weight or less and the amount of ash is 50% by weight or less. Acrylic rubber veils up to 0.4% by weight are provided.

In the acrylic rubber veil of the present invention, the amount of methyl ethyl ketone insoluble is preferably 10% by weight or less.
In the acrylic rubber veil of the present invention, it is preferable that the values when the amount of insoluble matter of methyl ethyl ketone is measured at 20 points are all within the range of (average value ± 5)% by weight.

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

In the acrylic rubber veil of the present invention, the ash content is preferably in the range of 0.001 to 0.2% by weight.

In the acrylic rubber veil of the present invention, the total amount of sodium, magnesium, calcium, phosphorus and sulfur in the ash is preferably 50% by weight or more.

In the acrylic rubber veil of the present invention, the total amount of magnesium and phosphorus in the ash is preferably 50% by weight or more.

In the acrylic rubber veil of the present invention, the weight average molecular weight (Mw) of the absolute molecular weight measured by the GPC-MALS method is preferably 1 million or more.

In the acrylic rubber veil of the present invention, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the absolute molecular weight distribution measured by the GPC-MALS method is 3.5 or more. Is preferable.

In the acrylic rubber veil of the present invention, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the absolute molecular weight distribution measured by the GPC-MALS method is 3.8 or more. Is preferable.

In the acrylic rubber veil of the present invention, the ratio (Mz / Mw) of the z average molecular weight (Mz) and the weight average molecular weight (Mw) of the absolute molecular weight distribution measured by the GPC-MALS method is 1.3 or more. Is preferable.

Further, the acrylic rubber veil of the present invention is preferably an acrylic rubber obtained by emulsion polymerization using a phosphate ester salt or a sulfate ester salt as an emulsifier, and the acrylic rubber emulsion-polymerized polymer solution is an alkali metal salt. Alternatively, it is preferably solidified by using a Group 2 metal salt of the periodic table as a coagulant and dried. Further, in the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is melt-kneaded and dried after solidification, and the melt-kneading and drying are carried out in a state where the moisture is substantially free. It is preferable that the melt kneading and drying are carried out under reduced pressure. Further, in the acrylic rubber veil of the present invention, it is preferable that the acrylic rubber is cooled at a cooling rate of 40 ° C./hr or more after the above-mentioned melt kneading and drying.

In the acrylic rubber veil of the present invention, it is preferable that the water-containing crumb having a particle diameter in the range of 710 μm to 6.7 mm and having a proportion of 50% by weight or more is washed, dehydrated and dried.

According to the present invention, an acrylic rubber monomer component containing a monomer containing at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom is emulsion with water and an emulsifier. Emulsion step to polymerize In the presence of a redox catalyst containing an inorganic radical generator and a reducing agent, polymerization is started, and a chain transfer agent is added in batches during the polymerization to continue polymerization and obtain an emulsion polymerization solution. When,
A coagulation step of adding the obtained emulsion polymerization solution to the stirring coagulation liquid to coagulate and generate a hydrous crumb,
A cleaning process that cleans the generated hydrous crumb with warm water,
A dehydration process to dehydrate the washed water-containing crumbs,
A drying process that dries the dehydrated hydrous crumb to less than 1% by weight,
A veiling process for veiling dried dried rubber,
A method for manufacturing an acrylic rubber veil including the above is provided.

The method for producing an acrylic rubber veil of the present invention is preferably the method for producing an acrylic rubber veil for producing the above-mentioned acrylic rubber veil.
In the method for producing an acrylic rubber veil of the present invention, it is preferable to carry out emulsion polymerization using a phosphate ester salt or a sulfate ester salt as an emulsifier in the emulsion polymerization step.

In the method for producing an acrylic rubber veil of the present invention, it is preferable that the polymerization solution produced in the emulsion polymerization step is coagulated by using an alkali metal salt or a metal salt of Group 2 of the periodic table as a coagulant and dried.
In the method for producing an acrylic rubber veil of the present invention, the polymerization solution produced in the emulsion polymerization step is added to an aqueous solution containing a coagulant containing an alkali metal salt or a metal salt of Group 2 of the periodic table and coagulated by stirring. Is preferable.

In the method for producing an acrylic rubber veil of the present invention, it is preferable that the polymerization solution produced in the emulsion polymerization step is brought into contact with a coagulant to coagulate, and then melt-kneaded and dried.
In the method for producing an acrylic rubber veil of the present invention, it is preferable that the melt kneading and drying are carried out in a state of substantially no moisture.
In the method for producing an acrylic rubber veil of the present invention, it is preferable that the above-mentioned melt kneading and drying are performed under reduced pressure.
In the method for producing an acrylic rubber veil of the present invention, it is preferable to cool the acrylic rubber after melt kneading and drying at a cooling rate of 40 ° C./hr or more.

In the method for producing an acrylic rubber veil of the present invention, it is preferable to wash, dehydrate, and dry a water-containing crumb having a particle size in the range of 710 μm to 6.7 mm and a proportion of 50% by weight or more.

According to the present invention, there is also provided a rubber composition containing a rubber component containing the acrylic rubber veil, a filler and a cross-linking agent.

In the rubber composition of the present invention, it is preferable that the filler is a reinforcing filler. Further, in the rubber composition of the present invention, it is preferable that the filler is carbon blacks. Further, in the rubber composition of the present invention, it is preferable that the filler is silica.

In the rubber composition of the present invention, it is preferable that the cross-linking agent is an organic cross-linking agent. Further, in the rubber composition of the present invention, it is preferable that the cross-linking agent is a polyvalent compound. Further, in the rubber composition of the present invention, it is preferable that the cross-linking agent is an ionic cross-linking compound. Further, in the rubber composition of the present invention, it is preferable that the cross-linking agent is an ionic cross-linking organic compound. Further, in the rubber composition of the present invention, it is preferable that the cross-linking agent is a polyvalent ion organic compound.

In the rubber composition of the present invention, the ion of the ion-crosslinkable compound, the ion-crosslinkable organic compound or the polyvalent ion organic compound as the cross-linking agent is selected from the group consisting of an amino group, an epoxy group, a carboxyl group and a thiol group. It is preferably at least one ionic reactive group.

In the rubber composition of the present invention, the cross-linking agent is at least one polyvalent ion compound selected from the group consisting of a polyvalent amine compound, a polyvalent epoxy compound, a polyvalent carboxylic acid compound and a polyvalent thiol compound. Is preferable.

In the rubber composition of the present invention, the content of the cross-linking agent is preferably in the range of 0.001 to 20 parts by weight with respect to 100 parts by weight of the rubber component.

The rubber composition of the present invention preferably further contains an anti-aging agent. In the rubber composition of the present invention, the anti-aging agent is preferably an amine-based anti-aging agent.

According to the present invention, there is also provided a method for producing a rubber composition in which a rubber component containing the above acrylic rubber veil, a filler and, if necessary, an antiaging agent are mixed, and then a cross-linking agent is mixed.

According to the present invention, a rubber crosslinked product obtained by cross-linking the above rubber composition is further provided. In the rubber crosslinked product of the present invention, it is preferable that the crosslinking of the rubber composition is performed after molding. Further, in the rubber crosslinked product of the present invention, it is preferable that the cross-linking of the rubber composition performs primary cross-linking and secondary cross-linking.

According to the present invention, an acrylic rubber bale having excellent roll workability and Banbury workability, and having a highly balanced water resistance and compression set resistance of a crosslinked product, an efficient manufacturing method thereof, and the acrylic rubber bale. A high-quality rubber composition containing the above and a rubber crosslinked product obtained by cross-linking the same 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 has at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom, and is absolutely measured by the GPC-MALS method using a dimethylformamide-based solvent as a developing solvent. It is made of acrylic rubber having a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the molecular weight distribution of 3.4 or more, and has an insoluble content of methyl ethyl ketone of 50% by weight or less and an ash content. Is 0.4% by weight or less. Here, the "GPC-MALS method" has the following contents. The GPC (gel permeation chromatography) method is a kind of liquid chromatography in which separation is performed based on the difference in molecular size. A multi-angle laser light scattering photometric meter (MALS) and a differential refractometer (RI) are incorporated into this device, and the light scattering intensity and refractive index difference of the molecular chain solution size-separated by the GPC device are measured with the melting time. This is a method of sequentially calculating the molecular weight of the solute and its content, and finally obtaining the absolute molecular weight distribution and the absolute average molecular weight value of the polymer substance.

<Reactive group>
The acrylic rubber veil of the present invention has at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom.
The at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom is not particularly limited, but is preferably an ionic reactive group that undergoes an ionic reaction, and more preferably an epoxy group or a carboxyl. When it is a group, particularly preferably a carboxyl group, it is suitable because it can highly improve the crosslinkability in a short time and the compression set resistance and water resistance of the crosslinked product.

The content of at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom of the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected according to the purpose of use. The reactive group itself is usually 0.001 to 5% by weight, preferably 0.01 to 3% by weight, more preferably 0.05 to 1% by weight, and particularly preferably 0.1 to 0% by weight. When it is in the range of 5% by weight, the acrylic rubber bale has high workability and crosslinkability, and the strength characteristics, compression permanent strain resistance, oil resistance, cold resistance, and water resistance of the crosslinked product are high. It is suitable because it is balanced with.

The acrylic rubber veil having at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom of the present invention is selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom in a post-reaction to acrylic rubber. It may be the one in which at least one kind of reactive group is introduced, but it is preferably an acrylic rubber in which the reactive group-containing monomer is copolymerized.

<Monomer component>
The monomer component of the acrylic rubber constituting the acrylic rubber veil of the present invention is not particularly limited as long as it is a monomer constituting an ordinary acrylic rubber, but is preferably composed of a carboxyl group, an epoxy group and a chlorine atom. Acrylic rubber monomer component containing a monomer containing at least one reactive group selected from the group, more preferably selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester. A monomer containing at least one reactive group selected from the group consisting of at least one (meth) acrylic acid ester, a carboxyl group, an epoxy group and a chlorine atom, and a monomer that can be copolymerized as required. It is composed of the monomer of. In the present invention, "(meth) acrylic acid ester" is used as a general term for esters of acrylic acid and / or methacrylic acid.

The preferred monomer component of the acrylic rubber of the present invention is at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester, a carboxyl group, and an epoxy. It consists of a monomer containing at least one reactive group selected from the group consisting of groups and chlorine atoms, and other monomers copolymerizable as needed.

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

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. Examples thereof include butyl, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, and among these, ethyl (meth) acrylate, (meth). ) N-butyl acrylate is preferable, and ethyl acrylate and n-butyl acrylate are more preferable.

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

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. These proportions in the total components of the weight are usually 50-99.99% by weight, preferably 62-99.95% by weight, more preferably 74-99.9% by weight, particularly preferably 80-99.5% by weight. %, Most preferably in the range of 87 to 99% by weight, the acrylic rubber is highly excellent in weather resistance, heat resistance and oil resistance.

The monomer containing at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom is appropriately selected depending on the purpose of use, but preferably has a carboxyl group and an epoxy group. When it is a monomer, more preferably a monomer having a carboxyl group, it is suitable because it can highly improve the crosslinkability in a short time and the compression set resistance and water resistance of the crosslinked product.

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 resistance permanent strain property when the acrylic rubber is used as a rubber crosslinked product.

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

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

The ethylenically unsaturated dicarboxylic acid monoester is not particularly limited, but 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 12 carbon atoms. Examples thereof include ethylenically unsaturated dicarboxylic acid of 6 and an alkyl monoester having 2 to 8 carbon atoms, more preferably an alkyl monoester having 2 to 6 carbon atoms of butendionic acid having 4 carbon atoms.

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

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

The monomer having a chlorine atom is not particularly limited, but for example, an unsaturated alcohol ester of a saturated carboxylic acid containing a chlorine atom, a (meth) acrylic acid chloroalkyl ester, and a (meth) acrylic acid chloroacyloxy. Alkyl ester, (meth) acrylic acid (chloroacetylcarbamoyloxy) alkyl ester, chlorine atom-containing unsaturated ether, chlorine atom-containing unsaturated ketone, chloromethyl group-containing aromatic vinyl compound, chlorine atom-containing unsaturated amide, chloroacetyl group Examples thereof include unsaturated monomers contained.

Specific examples of the unsaturated alcohol ester of the chlorine atom-containing saturated carboxylic acid include vinyl chloroacetate, vinyl 2-chloropropionate, and allyl chloroacetic acid. Specific examples of (meth) acrylic acid chloroalkyl ester include (meth) acrylic acid chloromethyl, (meth) acrylic acid 1-chloroethyl, (meth) acrylic acid 2-chloroethyl, and (meth) acrylic acid 1,2-dichloroethyl. , (Meta) acrylic acid 2-chloropropyl, (meth) acrylic acid 3-chloropropyl, (meth) acrylic acid 2,3-dichloropropyl and the like. Specific examples of (meth) acrylic acid chloroacyloxyalkyl ester include (meth) acrylic acid 2- (chloroacetoxy) ethyl, (meth) acrylic acid 2- (chloroacetoxy) propyl, and (meth) acrylic acid 3- (chloro). Examples thereof include acetoxy) propyl and 3- (hydroxychloroacetoxy) propyl (meth) acrylate. Examples of the (meth) acrylic acid (chloroacetylcarbamoyloxy) alkyl ester include (meth) acrylic acid 2- (chloroacetylcarbamoyloxy) ethyl and (meth) acrylic acid 3- (chloroacetylcarbamoyloxy) propyl. Be done. Specific examples of the chlorine atom-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. Specific examples of the chlorine atom-containing unsaturated ketone include 2-chloroethyl vinyl ketone, 3-chloropropyl vinyl ketone, 2-chloroethyl allyl ketone and the like. Specific examples of the chloromethyl group-containing aromatic vinyl compound include p-chloromethylstyrene, m-chloromethylstyrene, o-chloromethylstyrene, p-chloromethyl-α-methylstyrene and the like. Specific examples of the chlorine atom-containing unsaturated amide include N-chloromethyl (meth) acrylamide. Specific examples of the chloroacetyl group-containing unsaturated monomer include 3- (hydroxychloroacetoxy) propyl allyl ether and p-vinylbenzylchloroacetic acid ester.

The monomer containing at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom is used alone or in combination of two or more, and is used in all the components of the monomer. The proportion is usually 0.01 to 10% by weight, preferably 0.05 to 8% by weight, more preferably 0.1 to 6% by weight, particularly preferably 0.5 to 5% by weight, and most preferably 1 to 3%. It is in the range of% by weight.

As a monomer other than the above (abbreviated as "other monomer" in the present invention) that can be used together with each of the above monomers as needed, any monomer copolymerizable with the above monomer can be used. There are no particular restrictions, for example, aromatic vinyl such as styrene, α-methylstyrene, divinylbenzene; ethylenically unsaturated nitriles such as acrylonitrile and methacrylonitrile; acrylamide-based monomers such as acrylamide and methacrylicamide; ethylene. , Olefin monomers such as propylene, vinyl acetate, ethyl vinyl ether, butyl vinyl ether and the like.

These other monomers are used alone or in combination of two or more, and the ratio in the total components of the monomer is usually 0 to 40% by weight, preferably 0 to 30% by weight, and more preferably 0. It is suppressed to the range of about 20% by weight, particularly preferably 0 to 15% by weight, and most preferably 0 to 10% by weight.

<Acrylic rubber>
The acrylic rubber constituting the acrylic rubber veil of the present invention has at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom, preferably a (meth) acrylic acid alkyl ester and a (meth) acrylic acid alkyl ester. ) Monomer containing at least one (meth) acrylic acid ester selected from the group consisting of acrylic acid alkoxyalkyl esters, and at least one reactive group selected from the group consisting of carboxyl groups, epoxy groups and chlorine atoms. And, if necessary, binding units from other monomers, each proportion in acrylic rubber is selected from the group consisting of (meth) acrylic acid alkyl esters and (meth) acrylic acid alkoxyalkyl esters. The binding unit derived from at least one (meth) acrylic acid ester is usually 50 to 99.99% by weight, preferably 62 to 99.95% by weight, more preferably 74 to 99.9% by weight, and particularly preferably 80. Bonds derived from a monomer containing at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom, in the range of ~ 99.5% by weight, most preferably 87 to 99% by weight. The unit is usually 0.01 to 10% by weight, preferably 0.05 to 8% by weight, more preferably 0.1 to 6% by weight, particularly preferably 0.5 to 5% by weight, and most preferably 1 to 3%. In the range of% by weight, the binding unit derived from other monomers is usually 0 to 40% by weight, preferably 0 to 30% by weight, more preferably 0 to 20% by weight, and particularly preferably 0 to 15% by weight. Most preferably, it is in the range of 0 to 10% by weight. When the monomer composition of the acrylic rubber is in this range, the properties such as short-time cross-linking property, compression permanent strain resistance, weather resistance, heat resistance, and oil resistance of the acrylic rubber veil are highly balanced and suitable. ..

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 the GPC-MALS method using dimethylformamide as a developing solvent, and is usually 1 million or more. It is preferably 1.2 million or more, more preferably 1.5 million or more. If the weight average molecular weight (Mw) of the acrylic rubber constituting the acrylic rubber veil of the present invention is excessively small, the strength characteristics and the compression resistance permanent strain characteristics are inferior, which is not preferable. The weight average molecular weight (Mw) of the acrylic rubber of the present invention is also usually 1 million to 3.5 million, preferably 1.2 million to 3 million, more preferably 1.3 million to 3 million, particularly preferably 1.5 million to 2.5 million, most. When the range is preferably in the range of 1.9 million to 2.1 million, the roll processability, strength characteristics, and compression resistance permanent strain characteristics of the acrylic rubber veil are highly balanced and suitable.

The number average molecular weight (Mn) of the acrylic rubber constituting the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected depending on the intended use. However, GPC-MALS using a dimethylformamide-based solvent as a developing solvent is used. The absolute molecular weight measured by the method is usually 100,000 to 500,000, preferably 200,000 to 480,000, more preferably 250,000 to 450,000, particularly preferably 300,000 to 400,000, and most preferably 350,000 to 400,000. When the range is within the above range, the roll processability, strength characteristics and compression resistance permanent strain characteristics of the acrylic rubber bale are highly balanced and suitable.

The z average molecular weight (Mz) of the acrylic rubber constituting the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected depending on the intended use, but GPC-MALS using a dimethylformamide-based solvent as a developing solvent. Absolute molecular weight with an emphasis on the high molecular weight region measured by the method, usually in the range of 1.5 million to 6 million, preferably 2 million to 5 million, more preferably 2.5 million to 4.5 million, and particularly preferably 3 million to 4 million. At one point, the roll processability, strength characteristics, and compression-resistant permanent strain resistance of the acrylic rubber veil are highly balanced and 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 was measured by the GPC-MALS method using a dimethylformamide-based solvent as a developing solvent. The absolute molecular weight distribution is 3.4 or more, preferably 3.5 or more, more preferably 3.6 or more, still more preferably 3.7 or more, particularly preferably 3.8 or more, and most preferably 4 or more. If the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the acrylic rubber of the present invention is excessively small, the roll processability of the acrylic rubber veil is inferior, which is not preferable. 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 also usually 3.7 to 6.5, preferably 3. It was crosslinked with the roll processability of the acrylic rubber veil when it was in the range of 8 to 6.2, more preferably 4 to 6, particularly preferably 4, 5 to 5.7, and most preferably 4.7 to 5.5. It is suitable because it can highly balance the strength characteristics and the compression resistance permanent strain characteristics of the case.

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 may be appropriately selected according to the purpose of use without any particular limitation. However, it is an absolute molecular weight distribution that emphasizes the polymer region measured by the GPC-MALS method using a dimethylformamide-based solvent as a developing solvent, and is usually 1.3 to 3, preferably 1.4 to 2.7, and more preferably 1. The processability and strength characteristics of the acrylic rubber veil are highly balanced and stored in the range of .5 to 2.5, particularly preferably 1.8 to 2, most preferably 1.8 to 1.95. It is suitable because it can alleviate changes in physical properties.

The dimethylformamide-based solvent used as the measurement solvent in the GPC-MALS method is not particularly limited as long as it contains dimethylformamide as a main component. For example, 100% dimethylformamide or the ratio of dimethylformamide in the dimethylformamide-based solvent. However, 90% by weight, preferably 95% by weight, more preferably 97% by weight or more is used. The compound to be added to dimethylformamide is not particularly limited, but in the present invention, lithium chloride is added to dimethylformamide at a concentration of 0.05 mol / L and 37% concentrated hydrochloric acid is added at a concentration of 0.01%, respectively. Dimethylformamide is suitable.

The glass transition temperature (Tg) of the acrylic rubber constituting the acrylic rubber veil of the present invention may be appropriately selected depending on the intended use of the acrylic rubber, but is usually 20 ° C. or lower, preferably 10 ° C. or lower, more preferably. It is suitable because it has excellent workability and cold resistance when the temperature is 0 ° C. or lower. The lower limit of the glass transition temperature (Tg) of acrylic rubber is not particularly limited, but is usually −80 ° C. or higher, preferably −60 ° C. or higher, and more preferably −40 ° C. or higher. By setting the glass transition temperature to the above lower limit or higher, the acrylic rubber veil can be made superior in oil resistance and heat resistance, and by making it below the above upper limit, it can be made excellent in processability, crosslinkability and cold resistance. Can be.

<Acrylic rubber veil>
The acrylic rubber veil of the present invention has at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom, preferably made of the above acrylic rubber, and has an insoluble amount of methyl ethyl ketone of 50% by weight. It is characterized in that the ash content is 0.4% by weight or less at% or less.

The amount of acrylic rubber in the acrylic rubber veil of the present invention is almost acrylic rubber and is not particularly limited, but is usually 90% by weight or more, preferably 95% by weight or more, more preferably 98% by weight or more, still more preferably. It is 99% by weight or more. The amount of acrylic rubber in the acrylic rubber veil of the present invention is estimated by subtracting the amount of ash from the weight of the acrylic rubber veil.

The insoluble content of the methyl ethyl ketone of the acrylic rubber veil of the present invention is 50% by weight or less, preferably 30% by weight or less, more preferably 15% by weight or less, particularly preferably 10% by weight or less, and most preferably 5% by weight or less. At a certain time, the processability at the time of kneading such as Banbury is highly improved and is suitable.

The value when the amount of methyl ethyl ketone insoluble in the acrylic rubber veil of the present invention is arbitrarily measured at 20 points is not particularly limited, but all 20 points are within the range of (average value ± 5)% by weight. It is preferable that when all 20 points are within the range of (average value ± 3)% by weight, there is no workability variation and various physical properties of the rubber composition and the rubber crosslinked product are stabilized. It should be noted that the value when the amount of methyl ethyl ketone insoluble in the acrylic rubber veil is arbitrarily measured at 20 points is that all 20 points are within the range of the average value ± 5, (average value -5) to (average value +5). It means that all the measured insoluble amounts of methyl ethyl ketone at 20 points are included in the range of% by weight. For example, when the average value of the measured insoluble amount of methyl ethyl ketone is 20% by weight, it is 15 to 25% by weight. It means that all 20 measured values are within the range.

The acrylic rubber veil of the present invention is obtained by melt-kneading and drying a water-containing crumb produced by a solidification reaction in a state where almost all water is removed by a screw-type twin-screw extruder (water content less than 1% by weight). Sometimes Banbury workability and strength characteristics are highly balanced and suitable.

The ash content of the acrylic rubber veil of the present invention is 0.4% by weight or less, preferably 0.3% by weight or less, more preferably 0.2% by weight or less, still more preferably 0.18% by weight or less, and particularly preferably 0.18% by weight or less. It is 0.15% by weight or less, most preferably 0.13% by weight or less, and when it is in this range, the water resistance, strength characteristics and workability of the acrylic rubber veil are highly balanced and suitable.

The lower limit of the ash content of the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected depending on the intended use, but is usually 0.0001% by weight or more, preferably 0.0005% by weight or more. When it is preferably 0.001% by weight or more, more preferably 0.003% by weight or more, particularly preferably 0.005% by weight or more, and most preferably 0.01% by weight or more, the metal adhesion of the rubber is reduced. It is suitable because it has excellent workability.

When the acrylic rubber veil of the present invention has a high balance of water resistance, strength characteristics, workability and workability, the ash content is usually 0.0001 to 0.4% by weight, preferably 0.0005 to 0.3. %% by weight, more preferably 0.001 to 0.2% by weight, even more preferably 0.003 to 0.18% by weight, particularly preferably 0.005 to 0.15% by weight, most preferably 0.01 to 0%. It is in the range of .13% by weight.

The total amount of sodium, magnesium, calcium, phosphorus and sulfur in the ash content of the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected depending on the purpose of use, but is usually 50% by weight or more, preferably 50% by weight or more. When it is 60% by weight or more, more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more, the water resistance of the acrylic rubber is highly improved and preferable. Further, when the total amount of sodium, magnesium, calcium, phosphorus and sulfur in the ash content of the acrylic rubber of the present invention is in this range, the metal adhesion is reduced and the workability is excellent and suitable.

The total amount of magnesium and phosphorus in the ash content of the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected depending on the intended use, but is usually 30% by weight or more, preferably 50% by weight or more. When it is more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more, the water resistance, strength characteristics and processability of the acrylic rubber are highly balanced and preferable. Further, when the total amount of magnesium and phosphorus in the ash content of the acrylic rubber of the present invention is within this range, the metal adhesion is reduced and the workability is excellent and suitable.

The amount of magnesium in the ash content of the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected depending on the intended use, but is usually 10% by weight or more, preferably 15 to 60% by weight, and more preferably 20 to 50% by weight. It is in the range of% by weight, particularly preferably 25 to 45% by weight, and most preferably 30 to 40% by weight.

The amount of phosphorus in the ash content of the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected depending on the intended use, but is usually 10% by weight or more, preferably 20 to 90% by weight, and more preferably 30 to 80% by weight. It is in the range of% by weight, particularly preferably 40 to 70% by weight, and most preferably 50 to 60% by weight.

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 and may be appropriately selected according to the purpose of use, but is usually a weight ratio. The range is 0.4 to 2.5, preferably 0.45 to 1.2, more preferably 0.45 to 1, particularly preferably 0.5 to 0.8, and most preferably 0.55 to 0.7. When it is, the water resistance, strength characteristics and processability of acrylic rubber are highly balanced and suitable.

Here, the ash content in the acrylic rubber veil is mainly derived from the emulsifier used when emulsifying the monomer component and emulsion polymerization and the coagulant used when coagulating the emulsion polymerization solution, but the total ash content. The content of magnesium and phosphorus in the ash and the content of magnesium and phosphorus vary not only with the conditions of the emulsion polymerization step and the solidification step but also with the conditions of each subsequent step.

When the acrylic rubber veil of the present invention uses an anionic emulsifier, a cationic emulsifier, or a nonionic emulsifier, preferably an anionic emulsifier, more preferably a phosphoric acid ester salt or a sulfate ester salt, as an emulsifier during emulsion polymerization described later. In addition to water resistance and strength characteristics, mold releasability and workability can be highly improved, which is suitable. The water resistance of the acrylic rubber veil is uniquely correlated with the amount of ash in the acrylic rubber and the total amount of sodium, magnesium, calcium, phosphorus and sulfur in the ash. The water resistance, strength characteristics, mold releasability and processability of the above can be further balanced, which is suitable.

The acrylic rubber veil of the present invention has not only water resistance and strength characteristics but also mold releasability and mold releasability when a metal salt, preferably an alkali metal salt or a group 2 metal salt of the periodic table is used as a coagulant described later. It is suitable because it can greatly improve workability. The water resistance of the acrylic rubber veil is uniquely correlated with the amount of ash in the acrylic rubber and the total amount of sodium, magnesium, calcium, phosphorus and sulfur in the ash. The water resistance, strength characteristics, mold releasability and processability of the bale are more highly balanced and suitable.

The complex viscosity ([η] 60 ° C.) of the acrylic rubber veil of the present invention at 60 ° C. is not particularly limited and may be appropriately selected according to the purpose of use, but is usually 15,000 [Pa · s] or less. , Preferably 1,000 to 10,000 [Pa · s], more preferably 2,000 to 5,000 [Pa · s], particularly preferably 2,500 to 4,000 [Pa · s], most preferably. Is excellent in workability, oil resistance and shape retention when it is in the range of 2,500 to 3,000 [Pa · s] and is suitable.

The complex viscosity ([η] 100 ° C.) of the acrylic rubber veil of the present invention at 100 ° C. is not particularly limited and may be appropriately selected according to the purpose of use, but is usually 1,500 to 6,000 [Pa. S], preferably 2,000 to 5,000 [Pa · s], more preferably 2,300 to 4,000 [Pa · s], and particularly preferably 2,500 to 3,500 [Pa · s]. Most preferably, it is excellent in processability, oil resistance and shape retention when it is in the range of 2,500 to 3,000 [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 and may be appropriately selected according to the purpose of use, but is usually 0.5 or more, preferably 0.6 or more, more preferably 0.7 or more, particularly preferably 0.8 or more, and most. It is preferably 0.83 or more. 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.) Also, usually 0.5 to 0.99, preferably 0.6 to 0.98, more preferably 0.7 to 0.97, particularly preferably 0.8 to 0.96, most preferably 0. When the range is in the range of 85 to 0.95, workability, oil resistance, and shape retention are highly balanced and suitable.

The water content of the acrylic rubber veil of the present invention is not particularly limited and is appropriately selected depending on the intended use, but is usually less than 1% by weight, preferably 0.8% by weight or less, more preferably 0.6% by weight. When the following, the vulcanization characteristics of the acrylic rubber veil are optimized, and the characteristics such as heat resistance and strand-like water resistance are highly improved, which is suitable.

The pH of the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected depending on the intended use, but is usually 6 or less, preferably 2 to 6, more preferably 2.5 to 5.5, and most. The storage stability of the acrylic rubber veil is highly improved and is preferable when the range is preferably in the range of 3 to 5.

The Mooney viscosity (ML1 + 4,100 ° C.) of the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected depending on the intended use, but is usually 10 to 150, preferably 20 to 100, and more preferably 25. When the range is in the range of ~ 70, the processability and strength characteristics of the acrylic rubber veil are highly balanced and suitable.

The specific gravity of the acrylic rubber veil of the present invention is not particularly limited, but is usually 0.7 or more, preferably 0.75 or more, more preferably 0.8 or more, still more preferably 0.9 or more, particularly preferably. When it is 0.95 or more, most preferably 1 or more, almost no air is contained therein, and it is excellent in storage stability and suitable. The specific gravity of the acrylic rubber veil of the present invention is also usually 0.7 to 1.6, preferably 0.8 to 1.5, more preferably 0.9 to 1.4, and particularly preferably 0.95 to 1. 3.3, most preferably in the range of 1.0 to 1.2, productivity, storage stability, cross-linking property stability of crosslinked products, etc. are highly balanced and suitable. When the specific gravity of the acrylic rubber veil is excessively small, it indicates that the amount of air in the acrylic rubber is large, and it is not preferable because it greatly affects the storage stability including oxidative deterioration.
The specific gravity of the acrylic rubber veil of the present invention is obtained by dividing the mass by the capacity including voids, that is, the mass measured in the air divided by the buoyancy, and is usually JIS K6268 crosslinked rubber-A of density measurement. It is measured according to the law.

In the acrylic rubber veil of the present invention, the hydrous crumb produced by the solidification reaction is dried under reduced pressure by a screw type twin-screw extruder, or melt-kneaded and dried under reduced pressure to obtain storage stability. It is suitable because the roll workability and strength characteristics are particularly excellent and highly balanced.

The size of the acrylic rubber veil of the present invention is not particularly limited and may be appropriately selected depending on the intended use, but the width is usually in the range of 100 to 800 mm, preferably 200 to 500 mm, and more preferably 250 to 450 mm. The length is usually in the range of 300 to 1,200 mm, preferably 400 to 1,000 mm, more preferably 500 to 800 mm, and the height (thickness) is usually 50 to 500 mm, preferably 100 to 300 mm, more preferably. It is suitable to be in the range of 150 to 250 mm. Further, the shape of the acrylic rubber veil of the present invention is not limited and is appropriately selected depending on the intended use of the acrylic rubber veil, but in many cases, a rectangular parallelepiped is suitable.

<Manufacturing method of acrylic rubber veil>
The method for producing the acrylic rubber veil is not particularly limited, but for example, acrylic containing a monomer containing at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom. After the rubber monomer component is emulsified with water and an emulsifier, polymerization is started in the presence of a redox catalyst consisting of an inorganic radical generator and a reducing agent, and a chain transfer agent is added in batches during the polymerization to polymerize. The emulsion polymerization step of obtaining an emulsion polymerization solution, the coagulation step of adding the obtained emulsion polymerization solution to the stirring coagulation liquid and coagulating it to generate a water-containing crumb, and washing the produced water-containing crumb with warm water. Manufacture of acrylic rubber veil including a cleaning step, a dehydration step of dehydrating the washed hydrous crumb, a drying step of drying the dehydrated hydrous crumb to less than 1% by weight, and a veiling step of veiling the dried dried rubber. It can be easily manufactured by the method.

(Monomer component)
The monomer component containing a monomer containing at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom used in the present invention is an example of the above-mentioned monomer component. And the same as the preferred range. The amount of the monomer component used is also as described above, and in the emulsion polymerization, each monomer may be appropriately selected so as to have the above composition of the acrylic rubber of the present invention.

(emulsifier)
The emulsifier used in the present invention is not particularly limited, and examples thereof include an anionic emulsifier, a cationic emulsifier, and a nonionic emulsifier, and an anionic emulsifier is preferable.

The anionic emulsifier is not particularly limited, for example, salts of fatty acids such as myristic acid, palmitic acid, oleic acid, linolenic acid; alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate; sulfate esters such as sodium laurylsulfate. Phosphate ester salts such as salts and polyoxyalkylene alkyl ether phosphate ester salts; alkyl sulfosuccinates and the like can be mentioned. Among these anionic emulsifiers, phosphoric acid ester salts and sulfate ester salts are preferable, phosphoric acid ester salts are particularly preferable, and divalent phosphoric acid ester salts are most preferable, and the water resistance, strength characteristics, and gold of the obtained acrylic rubber veil are preferable. It is suitable because it can highly balance mold releasability and workability. The acrylic rubber veil obtained when these phosphate ester salts and sulfate ester salts are preferably alkali metal salts of phosphate esters and sulfate esters, and more preferably sodium salts of phosphate esters and sulfate esters. It is suitable because it can highly balance water resistance, strength characteristics, mold releasability and workability.

The divalent phosphoric acid ester salt is not particularly limited as long as it can be used as an emulsifier in the emulsification polymerization reaction, but is not particularly limited. Examples thereof include ester salts, among which these metal salts are preferable, these alkali metal salts are more preferable, and these sodium salts are most preferable.

Examples of the above-mentioned alkyloxypolyoxyalkylene phosphate ester salt include alkyloxypolyoxyethylene phosphoric acid ester salts and alkyloxypolyoxypropylene phosphate ester salts. Among these, alkyloxypolyoxyethylene phosphoric acid is used. Ester salts are preferred.

Specific examples of the alkyloxypolyoxyethylene phosphoric acid ester include octyloxydioxyethylene phosphoric acid ester, octyloxytrioxyethylene phosphoric acid ester, octyloxytetraoxyethylene phosphoric acid ester, and decyloxytetraoxyethylene phosphoric acid ester. , Dodecyloxytetraoxyethylene phosphoric acid ester, tridecyloxytetraoxyethylene phosphoric acid ester, tetradecyloxytetraoxyethylene phosphoric acid ester, hexadecyloxytetraoxyethylene phosphoric acid ester, octadecyloxytetraoxyethylene phosphoric acid ester, octyl Oxypentaoxyethylene phosphoric acid ester, decyloxypentaoxyethylene phosphoric acid ester, dodecyloxypentaoxyethylene phosphoric acid ester, tridecyloxypentaoxyethylene phosphoric acid ester, tetradecyloxypentaoxyethylene phosphoric acid ester, hexadecyloxypenta Oxyethylene Phosphate, Octadecyloxypentaoxyethylene Phosphate, Octyloxyhexaoxyethylene Phosphorate, Decyloxyhexaoxyethylene Phosphate, Dodecyloxyhexaoxyethylene Phosphate, Tridecyloxyhexaoxyethylene Phosphate Esters, Tetradecyloxyhexaoxyethylene Phosphate, Hexadecyloxyhexaoxyethylene Phosphate, Octadecyloxyhexaoxyethylene Phosphorus, Octyloxyoctaoxyethylene Phosphate, Decyloxyoctaoxyethylene Phosphate, Dodecyl Metal salts such as oxyoctaoxyethylene phosphoric acid ester, tridecyloxyoctaoxyethylene phosphoric acid ester, tetradecyloxyoctaoxyethylene phosphoric acid ester, hexadecyloxyoctaoxyethylene phosphoric acid ester, octadecyloxyoctaoxyethylene phosphoric acid ester, etc. Among these, alkali metal salts thereof, particularly sodium salts, are preferable.

Specific examples of the alkyloxypolyoxypropylene phosphate ester include octyloxydioxypropylene phosphate, octyloxytrioxypropylene phosphate, octyloxytetraoxypropylene phosphate, and decyloxytetraoxypropylene phosphate. , Dodecyloxytetraoxypropylene Phosphate, Tridecyloxytetraoxypropylene Phosphate, Tetradecyloxytetraoxypropylene Phosphate, Hexadecyloxytetraoxypropylene Phosphate, Octadecyloxytetraoxypropylene Phosphate, Octyl Oxypentaoxypropylene Phosphate, Decyloxypentaoxypropylene Phosphate, Dodecyloxypentaoxypropylene Phosphate, Tridecyloxypentaoxypropylene Phosphate, Tetradecyloxypentaoxypropylene Phosphate, Hexadecyloxypenta Oxypropylene Phosphate, Octadecyloxypentaoxypropylene Phosphate, Octyloxyhexaoxypropylene Phosphate, Decyloxyhexaoxypropylene Phosphate, Dodecyloxyhexaoxypropylene Phosphate, Tridecyloxyhexaoxypropylene Phosphate Ester, Tetradecyloxyhexaoxypropylene Phosphate, Hexadecyloxyhexaoxypropylene Phosphate, Octadecyloxyhexaoxypropylene Phosphate, Octyloxyoctaoxypropylene Phosphate, Decyloxyoctaoxypropylene Phosphate, Dodecyl Oxyoctaoxypropylene Phosphate, Tridecyloxyoctaoxyethylene Phosphate, Tetradecyloxyoctaoxypropylene Phosphate, Hexadecyloxyoctaoxypropylene Phosphate, Octadecyloxyoctaoxypropylene Phosphate and their metals Examples thereof include salts, and among these, alkali metal salts thereof, particularly sodium salts, are preferable.

Specific examples of the alkylphenyloxypolyoxyalkylene phosphate ester include alkylphenyloxypolyoxyethylene phosphate and alkylphenyloxypolyoxypropylene phosphate, among which alkylphenyloxypoly is used. Oxyethylene phosphate ester salts are preferred.

Specific examples of the alkylphenyloxypolyoxyethylene phosphate ester include methyloxyoxytetraoxyethylene phosphate, ethylphenyloxytetraoxyethylene phosphate, butylphenyloxytetraoxyethylene phosphate, and hexylphenyloxytetra. Oxyethylene Phosphate, Nonylphenyloxytetraoxyethylene Phosphorate, Dodecylphenyloxytetraoxyethylene Phosphate, Octadecyloxytetraoxyethylene Phosphate, Methylphenyloxypentaoxyethylene Phosphate, Ethylphenyloxypentaoxy Ethylene Phosphate, Butylphenyloxypentaoxyethylene Phosphate, Hexylphenyloxypentaoxyethylene Phosphate, Nonylphenyloxypentaoxyethylene Phosphate, Dodecylphenyloxypentaoxyethylene Phosphate, Methylphenyloxyhexaoxy Ethylene Phosphate, Ethylphenyloxyhexaoxyethylene Phosphorate, Butylphenyloxyhexaoxyethylene Phosphate, Hexylphenyloxyhexaoxyethylene Phosphorus, Nonylphenyloxyhexaoxyethylene Phosphorate, Dodecylphenyloxyhexaoxy Ethylene Phosphate, Methylphenyloxyhexaoxyethylene Phosphate, Ethylphenyloxyoctaoxyethylene Phosphate, Butylphenyloxyoctaoxyethylene Phosphate, Hexylphenyloxyoctaoxyethylene Phosphate, Nonylphenyloxyoctaoxy Examples thereof include metal salts such as ethylene phosphate ester and dodecylphenyloxyoctaoxyethylene phosphate ester, and among these, alkali metal salts thereof, particularly sodium salt, are preferable.

Specific examples of the alkylphenyloxypolyoxypropylene phosphate ester include methylphenyloxytetraoxypropylene phosphate, ethylphenyloxytetraoxypropylene phosphate, butylphenyloxytetraoxypropylene phosphate, and hexylphenyloxytetra. Oxypropylene Phosphate, Nonylphenyloxytetraoxypropylene Phosphate, Dodecylphenyloxytetraoxypropylene Phosphate, Methylphenyloxypentaoxypropylene Phosphate, Ethylphenyloxypentaoxypropylene Phosphate, Butylphenyloxypenta Oxypropylene Phosphate, Hexylphenyloxypentaoxypropylene Phosphate, Nonylphenyloxypentaoxypropylene Phosphate, Dodecylphenyloxypentaoxypropylene Phosphate, Methylphenyloxyhexaoxypropylene Phosphate, Ethylphenyloxyhexa Oxypropylene Phosphate, Butylphenyloxyhexaoxypropylene Phosphate, Hexylphenyloxyhexaoxypropylene Phosphate, Nonylphenyloxyhexaoxypropylene Phosphate, Dodecylphenyloxyhexaoxypropylene Phosphate, Methylphenyloxyocta Oxypropylene Phosphate, Ethylphenyloxyoctaoxypropylene Phosphate, Butylphenyloxyoctaoxypropylene Phosphate, Hexylphenyloxyoctaoxyethylene Phosphate, Nonylphenyloxyoctaoxypropylene Phosphate, Dodecylphenyloxyocta Examples thereof include metal salts such as oxypropylene phosphate, and among these, alkali metal salts thereof, particularly sodium salts, are preferable.

As the phosphoric acid ester salt, a monovalent phosphoric acid ester salt such as a di (alkyloxypolyoxyalkylene) phosphoric acid ester sodium salt can be used alone or in combination with a divalent phosphoric acid ester salt.
Examples of the sulfate ester salt include sodium lauryl sulfate, potassium lauryl sulfate, ammonium lauryl sulfate, sodium mystyl sulfate, sodium polyoxyethylene alkyl sulfate, sodium polyoxyethylene alkylaryl sulfate, and the like, and sodium lauryl sulfate is preferable.

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

Examples of the nonionic emulsifier include polyoxyalkylene fatty acid esters such as polyoxyethylene stearate 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.

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

The method of mixing the monomer component, water and emulsifier (mixing method) may follow a conventional method. For example, a method of stirring the monomer, emulsifier and water using a stirrer such as a homogenizer or a disk turbine. And so on. 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 3 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.

(Inorganic radical generator)
The polymerization catalyst used in the present invention is characterized by using a redox catalyst composed of an inorganic radical generator and a reducing agent. In particular, it is suitable because the processability of a roll or the like of an acrylic rubber veil manufactured by using an inorganic radical generator can be highly improved.

The inorganic radical generator is not particularly limited as long as it is usually used in emulsion polymerization, and examples thereof include persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate, hydrogen peroxide, and the like. Among them, persulfate is preferable, potassium persulfate and ammonium persulfate are more preferable, and potassium persulfate is particularly preferable.

These inorganic radical generators can be used individually or in combination of two or more, and the amount used is usually 0.0001 to 5 parts by weight, preferably 0, based on 100 parts by weight of the monomer component. It is in the range of 0005 to 1 part by weight, more preferably 0.001 to 0.25 part by weight, particularly preferably 0.01 to 0.21 part by weight, and most preferably 0.1 to 0.2 part by weight.

(Reducing agent)
The reducing agent used in the present invention is not particularly limited as long as it is usually used in emulsion polymerization, but preferably at least two kinds of reducing agents are used, and it is a metal ion compound in a reduced state. It is preferable to be able to further balance the vanbury workability, roll workability and strength characteristics of the acrylic rubber veil that can be obtained by combining with other reducing agents.

The metal ion compound in the reduced state is not particularly limited, and examples thereof include ferrous sulfate, sodium hexamethylenediamine tetraacetate, and ferrous naphthenate, and among these, ferrous sulfate is preferable. These metal ion compounds in the reduced state can be used alone or in combination of two or more, and the amount used is usually 0.000001 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 used in the present invention is not particularly limited, and is, for example, ascorbic acid such as ascorbic acid, sodium ascorbate, potassium ascorbate or a salt thereof; erythorbic acid, sodium erythorbicate. , Elysorbic acid such as potassium erythorbinate or a salt thereof; sulphinate such as sodium hydroxymethane sulfine; sodium sulfite, potassium sulfite, sodium hydrogen sulfite, sodium aldehyde hydrogen sulfite, sulfite of potassium hydrogen sulfite; sodium pyrosulfate, pyro Pyro sulfites such as potassium sulfite, sodium pyrosulfate, potassium pyrosulfate; thiosulfates such as sodium thiosulfate, potassium thiosulfate; Pyroarophosphate or a salt thereof; Pyroarophosphate or a salt thereof such as Pyrophosic acid, Sodium Pyrophosphite, Potassium Pyrophosphite, Sodium Pyrophosphite, Potassium hydrogen Pyrophosphite; Sodium formaldehyde sulfoxylate and the like. Be done. 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.

These reducing agents other than the metal ion compound in the reduced state can be used alone or in combination of two or more, and the amount used is usually 0.001 with respect to 100 parts by weight of the monomer component. The range is from 1 part by weight, preferably 0.005 to 0.5 part by weight, and more preferably 0.01 to 0.1 part by weight.

A preferred 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. It is a combination with alcorbic acid or a salt thereof. 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. The amount of ascorbic acid or a salt thereof and / or sodium formaldehyde sulfoxylate is usually 0.001 to 1 part by weight, preferably 0.001 to 1 part by weight, based on 100 parts by weight of both components. It is in the range of 0.005 to 0.5 parts by weight, more preferably 0.01 to 0.1 parts by weight.

The amount of water used in the emulsion polymerization reaction may be only the amount used at the time of emulsification of the monomer component, but is usually 10 to 1000 parts by weight, preferably 50 to 50 parts by weight with respect to 100 parts by weight of the monomer component used for 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 method of the emulsion polymerization reaction may be a conventional method, and may be a batch method, a semi-batch method, or a continuous method. The polymerization temperature and the polymerization time are not particularly limited and can be appropriately selected from the type of the polymerization initiator to be used and the like. The polymerization time is usually 0.5 to 100 hours, preferably 1 to 10 hours.

The emulsion polymerization reaction is an exothermic reaction, and if not controlled, the temperature may rise and the polymerization reaction can be shortened. However, in the present invention, the emulsion polymerization reaction temperature is usually 35 ° C. or lower, preferably 0 to 35 ° C., more preferably. It is preferable to control the temperature at 5 to 30 ° C, particularly preferably 10 to 25 ° C, because the strength characteristics of the produced acrylic rubber veil and the processability at the time of kneading such as Banbury are highly balanced.

(Post-addition of chain transfer agent)
The present invention is characterized in that the chain transfer agent is not added at the initial stage but is added in batches during the polymerization, whereby an acrylic rubber having a high molecular weight component and a low molecular weight component separated can be produced. , The strength characteristics of the acrylic rubber veil to be manufactured and the processability at the time of kneading such as rolls are highly balanced and suitable.

The chain transfer agent used is not particularly limited as long as it is usually used in emulsion polymerization, and for example, a mercaptan compound can be preferably used.
As the mercaptan compound, an alkyl mercaptan compound having 2 to 20 carbon atoms, preferably an alkyl mercaptan compound having 5 to 15 carbon atoms, and more preferably an alkyl mercaptan compound having 6 to 14 carbon atoms can be used.

The alkyl mercaptan compound may be any of n-alkyl mercaptan compound, sec-alkyl mercaptan compound and t-alkyl mercaptan compound, but is preferably n-alkyl mercaptan compound and t-alkyl mercaptan compound, and more preferably n-alkyl. When it is a mercaptan compound, the effect of the chain transfer agent can be stably exhibited, and the processability of the roll or the like of the produced acrylic rubber veil can be highly improved, which is suitable.

Specific examples of the alkyl mercaptan compound include n-pentyl mercaptan, n-hexyl mercaptan, n-heptyl mercaptan, n-octyl mercaptan, n-decyl mercaptan, n-dodecyl mercaptan, n-tridecane mercaptan, and n-tetradecyl mercaptan. , N-Hexadecyl mercaptan, n-octadecyl mercaptan, sec-pentyl mercaptan, sec-hexyl mercaptan, sec-heptyl mercaptan, sec-octyl mercaptan, sec-decyl mercaptan, sec-dodecyl mercaptan, sec-tridecane mercaptan, sec- Tetradecyl mercaptan, sec-hexadecyl mercaptan, sec-octadecyl mercaptan, t-pentyl mercaptan, t-hexyl mercaptan, t-heptyl mercaptan, t-octyl mercaptan, t-decyl mercaptan, t-dodecyl mercaptan, n-tridecane mercaptan , T-tetradecyl mercaptan, t-hexadecyl mercaptan, t-octadecyl mercaptan, etc., preferably n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, more preferably n-octyl mercaptan, n -Dodecyl mercaptan.

These chain transfer agents can be used alone or in combination of two or more. The amount of the chain transfer agent used is not particularly limited, but is usually 0.0001 to 1 part by weight, preferably 0.0005 to 0.5 part by weight, based on 100 parts by weight of the monomer component. Of the acrylic rubber veil produced, preferably in the range of 0.001 to 0.5 parts by weight, particularly preferably 0.005 to 0.1 parts by weight, most preferably 0.01 to 0.06 parts by weight. It is suitable because it has a high balance between strength characteristics and roll workability.

The present invention is characterized in that the chain transfer agent is not added at the initial stage of polymerization but is added in batches during the polymerization. It is suitable because the strength characteristics of the acrylic rubber veil and the processability of the roll or the like can be highly balanced with the above as a specific range.

The number of batch post-additions of the chain transfer agent is not particularly limited and is appropriately selected depending on the purpose of use, but is usually 1 to 5 times, preferably 2 to 4 times, more preferably 2 to 3 times. Particularly preferably, the strength characteristics of the acrylic rubber veil produced when the number of times is twice and the processability of the roll or the like can be highly balanced, which is preferable.

The time to start the batch post-addition of the chain transfer agent is not particularly limited and is appropriately selected according to the purpose of use, but is usually 20 minutes or later after the start of the polymerization, preferably 30 minutes or later after the start of the polymerization. The strength characteristics of the acrylic rubber veil and the processability of rolls and the like are more preferably 30 to 200 minutes after the start of polymerization, particularly preferably 35 to 150 minutes after the start of polymerization, and most preferably 40 to 120 minutes. Can be highly balanced and is suitable.

The amount to be added per batch in the batch post-addition of the chain transfer agent is not particularly limited and is appropriately selected according to the purpose of use, but is usually 0.00005 to 100 parts by weight of the monomer component. 0.5 parts by weight, preferably 0.0001 to 0.1 parts by weight, more preferably 0.0005 to 0.05 parts by weight, particularly preferably 0.001 to 0.03 parts by weight, most preferably 0.002. It is suitable because the strength characteristics and roll workability of the acrylic rubber veil manufactured when the content is in the range of about 0.02 parts by weight can be highly balanced.

After the addition of the chain transfer agent, there is no particular limitation, but the polymerization reaction can be continued for usually 30 minutes or longer, preferably 45 minutes or longer, more preferably 1 hour or longer, and then terminated.

(Addition after reducing agent)
In the present invention, the reducing agent of the redox catalyst can be post-added during the polymerization, and the strength characteristics of the acrylic rubber veil produced by doing so and the processability of the roll and the like can be highly balanced. Suitable.

As the reducing agent to be added after the polymerization, the above-mentioned examples of the reducing agent and the preferable range are the same. In the present invention, ascorbic acid or a salt thereof is suitable as the reducing agent to be added later.

The amount of the reducing agent to be added after the polymerization is not particularly limited and may be appropriately selected according to the purpose of use, but is usually 0.0001 to 1 with respect to 100 parts by weight of the monomer component. By weight, preferably 0.0005 to 0.5 parts by weight, more preferably 0.001 to 0.5 parts by weight, particularly preferably 0.005 to 0.1 parts by weight, most preferably 0.01 to 0. When the range is in the range of 05 parts by weight, the productivity of producing an acrylic rubber bale is excellent, and the strength characteristics and processability of the produced acrylic rubber bale can be highly balanced, which is suitable.

The reducing agent added after the polymerization may be continuous or batch, but is preferably batch. The number of times the reducing agent is added in batches during the polymerization is not particularly limited, but is usually 1 to 5 times, preferably 1 to 3 times, and more preferably 1 to 2 times.

When the reducing agent added at the initial stage and during the polymerization is ascorbic acid or a salt thereof, the ratio of the amount of ascorbic acid or a salt thereof added at the initial stage to the amount of ascorbic acid or a salt thereof added afterwards is exceptional. The weight ratio of "initially added ascorbic acid or a salt thereof" / "a batch post-added ascorbic acid or a salt thereof" is usually 1/9 to 8/2, preferably 2/8 to 2. When it is in the range of 6/4, more preferably 3/7 to 5/5, the productivity of acrylic rubber bale production is excellent, and the strength characteristics and workability of the produced acrylic rubber bale can be highly balanced, which is suitable. ..

The timing of the post-addition of the reducing agent is not particularly limited and is appropriately selected according to the purpose of use. However, it is usually 1 hour or later after the start of polymerization, preferably 1 to 3 hours after the start of polymerization, and more preferably 1. When the time is in the range of 5 to 2.5 hours, the productivity of producing an acrylic rubber bale is excellent, and the strength characteristics of the produced acrylic rubber bale and the processability of a roll or the like can be highly balanced, which is suitable.

The amount of the reducing agent added per batch in the batch post-addition is not particularly limited and is appropriately selected according to the purpose of use, but is usually 0.00005 to 0 with respect to 100 parts by weight of the monomer component. Manufactured in the range of 5.5 parts by weight, preferably 0.0001 to 0.1 parts by weight, more preferably 0.0005 to 0.05 parts by weight, and particularly preferably 0.001 to 0.03 parts by weight. It is suitable because it can highly balance the strength characteristics of the acrylic rubber veil and the workability of rolls and the like.

The operation after the addition of the reducing agent is not particularly limited, but the polymerization reaction can be terminated after the polymerization reaction is continued for usually 30 minutes or longer, preferably 45 minutes or longer, more preferably 1 hour or longer.

The polymerization conversion rate of the emulsion polymerization reaction is not particularly limited, but is usually 90% by weight or more, preferably 95% by weight or more, and the acrylic rubber veil produced at this time has excellent strength characteristics and a monomeric odor. Not suitable. A polymerization inhibitor may be used to terminate the polymerization.

(Coagulation process)
The coagulation method after emulsion polymerization is characterized in that the emulsion polymerization solution obtained by the above emulsion polymerization is added to the stirring coagulation solution and coagulated to form a water-containing crumb of acrylic rubber.

The solid content concentration of the emulsion polymer used in this coagulation reaction 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. Will be done.

The coagulant used in the coagulant is not particularly limited, but usually a metal salt is used. Examples of the metal salt include alkali metals, Group 2 metal salts of the Periodic Table, and other metal salts, preferably alkali metal salts, Group 2 metal salts of the Periodic Table, and more preferably Group 2 metals of the Periodic Table. It is suitable because it can highly balance the water resistance, strength characteristics, mold releasability and processability of the acrylic rubber obtained when it is a salt, particularly preferably a magnesium salt.

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

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

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

Each of these coagulants can be used alone or in combination of two or more, and the amount thereof is usually 0.01 to 100 parts by weight, preferably 0, with respect to 100 parts by weight of the monomer component. It is in the range of 1 to 50 parts by weight, more preferably 1 to 30 parts by weight. When the coagulant is in this range, it is suitable because it can sufficiently improve the coagulation of the acrylic rubber and highly improve the compression resistance permanent strain resistance and the water resistance when the acrylic rubber veil is crosslinked.

In the solidification step of the present invention, it is particularly preferable to focus the particle size of the water-containing crumb to be generated in a specific region, because the cleaning efficiency and the ash removal efficiency at the time of dehydration are significantly improved. The proportion of the water-containing crumb to be produced in the range of 710 μm to 6.7 mm (passing 6.7 mm without passing through 710 μm) is not particularly limited, but is usually 30% by weight or more, preferably 30% by weight or more, based on the total water-containing crumb. Is suitable because the water resistance of the acrylic rubber veil can be significantly improved when it is 50% by weight or more, more preferably 60% by weight or more, particularly preferably 70% by weight or more, and most preferably 80% by weight or more. Further, the ratio of the water-containing crumb to be produced in the range of 710 μm to 4.75 mm (passing 4.75 mm without passing through 710 μm) is not particularly limited, but is usually 30% by weight or more with respect to the total water-containing crumb. The water resistance of the acrylic rubber veil can be significantly improved when the content is preferably 50% by weight or more, more preferably 60% by weight or more, particularly preferably 70% by weight or more, and most preferably 80% by weight or more. Furthermore, the proportion of the water-containing crumbs produced in the range of 710 μm to 3.35 mm (passing 3.35 mm without passing through 710 μm) is not particularly limited, but is usually 20% by weight or more with respect to the total water-containing crumbs. The water resistance of the acrylic rubber veil can be significantly improved when the content is preferably 30% by weight or more, more preferably 40% by weight or more, particularly preferably 50% by weight or more, and most preferably 60% by weight or more.

The means for producing the particle size of the hydrous crumb to be produced within the above range is not particularly limited, but for example, the method of contacting the emulsion polymerization solution with the coagulant is a coagulation solution in which the emulsion polymerization solution is stirred (coagulation). It can be carried out by adding it to the agent aqueous solution), or by specifying the coagulant concentration of the coagulant, the number of stirrings of the coagulant being stirred, and the peripheral speed.

The coagulant used is usually used as an aqueous solution, and the concentration of the coagulant in the aqueous solution is not particularly limited, but is usually 0.1% by weight or more, preferably 0.5% by weight or more, more preferably 1. By weight or more, particularly preferably 1.5% by weight or more. The coagulant concentration of the coagulant is also usually in the range of 0.1 to 20% by weight, preferably 0.5 to 15% by weight, more preferably 1 to 10% by weight, particularly preferably 1.5 to 5% by weight. It is suitable because the particle size of the hydrous crumb generated in the above can be uniformly focused in a specific region.

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

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

It is preferable that the rotation speed is a rotation speed that is agitated violently to some extent because the water-containing crumb particle size to be generated can be made small and uniform. It is possible to suppress the formation of and, and by setting it to the upper limit or less, it is possible to more easily control the coagulation reaction.

The peripheral speed of the coagulated liquid being stirred, that is, the speed of the outer periphery of the stirring blade of the stirring device is not particularly limited, but the water-containing crumb particle size generated by being vigorously stirred to a certain degree is smaller and 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 is usually solidified when it is 50 m / s or less, preferably 30 m / s or less, more preferably 25 m / s or less, and most preferably 20 m / s or less. It is suitable because the reaction can be easily controlled.

A water-containing crumb produced by setting the above conditions of the coagulation reaction (addition method, solid content concentration of emulsion polymerization solution, concentration and temperature of coagulation liquid, rotation speed and peripheral speed of coagulation liquid at the time of stirring, etc.) in a specific range. The shape and crumb diameter of the product are uniform and focused, the removal of emulsifiers and coagulants during cleaning and dehydration is significantly improved, and the water resistance and storage stability of the resulting acrylic rubber veil can be greatly improved. Therefore, it is suitable.

(Washing process)
The cleaning step in the method for producing an acrylic rubber veil of the present invention is characterized in that the water-containing crumb produced by the coagulation reaction is washed with warm water.

The cleaning method is not particularly limited, and for example, the generated hydrous crumb can be mixed with a large amount of warm water.

The amount of hot water added for washing 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. It is preferable that the amount of ash in the acrylic rubber veil can be effectively reduced when the amount is preferably in the range of 100 to 10,000 parts by weight, more preferably 500 to 5,000 parts by weight.

The temperature of the hot water used is not particularly limited, but is usually 40 ° C. or higher, preferably 40 to 100 ° C., more preferably 50 to 90 ° C., and particularly when the temperature is 60 to 80 ° C., the cleaning efficiency can be significantly improved. It is the best. By setting the temperature of the water used to be equal to or higher than the above-mentioned lower limit, the emulsifier and coagulant are liberated from the water-containing crumb to further improve the cleaning efficiency.

The cleaning 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 also not particularly limited, and is usually 1 to 10 times, preferably 1 to 5 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 veil, it is desirable that the number of washings 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 doing so and / or setting the washing temperature within the above range, the number of washings with water can be significantly reduced.

(Dehydration process)
The dehydration step in the method for producing an acrylic rubber veil of the present invention is a step of dehydrating the washed water-containing crumb.

The method for dehydrating the water-containing crumb is not particularly limited as long as it can squeeze out the water from the water-containing crumb, and can usually be performed using a dehydrator or the like. As a result, the amount of ash content of the emulsifier and coagulant contained in the water-containing crumb that could not be removed in the cleaning step can be reduced, and the water resistance of the acrylic rubber can be significantly improved, which is preferable.

The dehydrator is not particularly limited, and for example, a centrifuge, a squeezer, a screw type extruder, or the like can be used, but in particular, the screw type extruder can highly reduce the water content of the water-containing crumb. Suitable. In a centrifuge or the like, the adhesive acrylic rubber adheres between the wall surface and the slit and can usually be dehydrated only to about 45 to 55% by weight. On the other hand, the screw type extruder is suitable because it has a mechanism for forcibly squeezing out water.

The water content of the hydrous crumb after dehydration is not limited, but is usually in the range of 1 to 50% by weight, preferably 1 to 40% by weight, more 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 lower limit, the dehydration time can be shortened and deterioration of the acrylic rubber can be suppressed, while by setting it to be equal to or lower than the above upper limit, the amount of ash can be sufficiently reduced.

(Drying process)
The drying step in the method for producing an acrylic rubber veil of the present invention is a step of drying the dehydrated hydrous crumb to less than 1% by weight.

The method for drying the hydrous crumb after dehydration is not particularly limited. For example, the hydrous crumb after dehydration may be dried by direct drying, but it is preferably performed using a screw type twin-screw extruder. be able to. The screw type twin-screw extruder used is not particularly limited as long as it is an extruder having two screws, but in the present invention, a screw type twin-screw extruder having two screws is particularly used. It is suitable because it can highly balance the roll processability, Banbury processability and strength characteristics of the acrylic rubber veil obtained by drying the hydrous crumb under the condition of high share.

In the present invention, acrylic rubber can be obtained by melting and extrusion-drying a water-containing crumb in a screw-type twin-screw extruder. The drying temperature (set temperature) of the screw type twin-screw extruder may be appropriately selected, but is usually in the range of 100 to 250 ° C, preferably 110 to 200 ° C, and more preferably 120 to 180 ° C. , Acrylic rubber is suitable because it can be dried efficiently without discoloration or deterioration.

In the present invention, when acrylic rubber is melted under reduced pressure in a screw-type twin-screw extruder and extruded and dried, the storage stability is highly improved without impairing the roll processability and strength characteristics of the acrylic rubber veil. It is enhanced and suitable. At this stage, the degree of depressurization in the screw type twin-screw extruder suitable for removing the air contained in the acrylic rubber and improving the storage stability may be appropriately selected, but is usually 1 to 50 kPa, preferably 1 to 50 kPa. Is in the range of 2 to 30 kPa, more preferably 3 to 20 kPa.

In the present invention, when the acrylic rubber is melt-kneaded and dried in a screw-type twin-screw extruder with almost all water removed, the roll processability and strength characteristics of the acrylic rubber veil are not impaired. Banbury workability is highly enhanced and suitable. The state in which most of the water has been removed, which can highly enhance the Banbury workability, may be appropriately selected, but the water content of the acrylic rubber is usually less than 1% by weight, preferably 0.8% by weight or less, more preferably. Is 0.6% by weight or less. The term "melt kneading" or "melt kneading and drying" as used in the present invention means that acrylic rubber is kneaded (mixed) or extruded in a molten state in a screw type twin-screw extruder, and the stage thereof. It means that acrylic rubber is kneaded in a molten (plasticized) state by a screw-type twin-screw extruder and then extruded and dried.

The maximum torque of the screw type twin-screw extruder used in the present invention is not particularly limited, but is usually 20 Nm or more, preferably 25 Nm or more, more preferably 30 Nm or more, and particularly preferably. Is 35 N · m or more, most preferably 40 N · m or more. The maximum torque of the screw type twin-screw extruder used in the present invention is also usually 25 to 125 Nm, preferably 30 to 100 Nm, more preferably 35 to 75 Nm, and particularly preferably 40 to 60 N. -When it is in the range of m, the roll processability, the bumper processability and the strength characteristics of the produced acrylic rubber veil can be highly balanced, which is suitable.

The specific power of the screw type twin-screw extruder used in the present invention is not particularly limited, but is usually 0.1 to 0.25 [kW · h / kg] or more, preferably 0.13 to 0. The acrylic rubber bale obtained in the range of 23 [kw · h / kg], more preferably 0.15 to 0.2 [kW · h / kg] has high roll workability, vanbury workability and strength characteristics. It is well-balanced and suitable.

The specific power of the screw type twin-screw extruder used in the present invention is not particularly limited, but is usually 0.2 to 0.6 [A · h / kg] or more, preferably 0.25 to 0. The acrylic rubber bale obtained when it is in the range of 55 [A · h / kg], more preferably 0.35 to 0.5 [A · h / kg] has high roll workability, Banbury workability and strength characteristics. It is well-balanced and suitable.

The shear rate of the screw type twin-screw extruder used in the present invention is not particularly limited, but is usually 40 to 150 [1 / s] or more, preferably 45 to 125 [1 / s], more preferably. The storage stability, roll workability, Banbury workability and strength characteristics of the acrylic rubber veil obtained in the range of 50 to 100 [1 / s] are highly balanced and suitable.

The shear viscosity of the acrylic rubber in the screw type twin-screw extruder used in the present invention is not particularly limited, but is usually 4000 to 8000 [Pa · s] or less, preferably 4500 to 7500 [Pa · s]. More preferably, the storage stability, roll processability, Banbury processability and strength characteristics of the acrylic rubber veil obtained in the range of 5000 to 7000 [Pa · s] are highly balanced and preferable.

The acrylic rubber veil of the present invention also has no particular limitation on the cooling rate after drying the acrylic rubber, but is usually 40 ° C./hr or more, preferably 50 ° C./hr or more, more preferably 100 ° C./hr or more. Particularly preferably, when the temperature is 150 ° C./hr or higher, the acrylic rubber veil is excellent in storage stability, roll workability, Banbury workability, strength characteristics, water resistance and compression set resistance, and scorch stability can be significantly improved. Suitable.

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

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

(Manufacturing method of acrylic rubber veil via sheet-shaped dry rubber)
In the present invention, an acrylic rubber veil having significantly excellent storage stability can be produced by extruding a sheet-shaped dry rubber with a screw-type twin-screw extruder and then laminating and bale. Specifically, the water content crumb after cleaning is subjected to a water content of 1 to 40 in a dehydration barrel using a dehydration barrel having a dehydration slit, a drying barrel under reduced pressure, and a screw type twin-screw extrusion dryer having a die at the tip. After dehydrating to weight%, it is dried to less than 1% by weight in a drying barrel, and the sheet-shaped dry rubber is extruded from the die. It is possible to produce an excellent acrylic rubber veil.

In the present invention, it is preferable that the water-containing crumb supplied to the screw type twin-screw extruder is one in which free water is removed (drained) after washing.

(Draining process)
In the present invention, it is preferable to provide a draining step for separating free water from the water-containing crumb after washing with a draining machine in order to improve the dehydration efficiency.

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

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

The water content of the water-containing crumb after draining, that is, the water content 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, and more. It is preferably in the range of 50 to 60% by weight.

The temperature of the water-containing crumb after draining, that is, the temperature of the water-containing crumb put into the dehydration / drying step is not particularly limited, but is usually 40 ° C. or higher, preferably 40 to 100 ° C., more preferably 50 to 90 ° C. When the temperature is in the range of ° C., particularly preferably 55 to 85 ° C., and most preferably 60 to 80 ° C., the specific heat is as high as 1.5 to 2.5 KJ / kg · K as in the acrylic rubber of the present invention. It is suitable because difficult water-containing crumbs can be efficiently dehydrated and dried using a screw-type twin-screw extruder.

(Dehydration of hydrous crumbs in the dehydration barrel)
Dehydration of the water-containing crumb is performed in a dehydration barrel in a screw-type twin-screw extruder with a dehydration slit. The opening of the dehydration slit may be appropriately selected according to the usage conditions, but is usually in the range of 0.01 to 5 mm, preferably 0.1 to 1 mm, and more preferably 0.2 to 0.6 mm. In addition, the water-containing crumb loss is small and the water-containing crumb can be efficiently dehydrated, which is suitable.

The number of dehydration barrels in the screw type twin-screw extruder is not particularly limited, but is usually a plurality, preferably 2 to 10, more preferably 3 to 6, and sticky acrylic rubber. It is suitable for efficient dehydration.

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

The water discharged from the dehydration slit in the dehydration of the water-containing crumb may be in a liquid (drainage) state or a steam state (exhaust steam), but it is carried out using a screw type twin-screw extruder equipped with a plurality of dehydration barrels. In this case, it is preferable to combine drainage and exhaust steam because the adhesive acrylic rubber can be efficiently dehydrated. The selection of a drainage type dehydration barrel or a steam exhaust type dehydration barrel of a screw type twin-screw extruder equipped with three or more dehydration barrels may be appropriately performed according to the purpose of use, but ash in acrylic rubber usually produced. If the amount is to be reduced, the number of drainage barrels is increased, and if the amount of water is to be reduced, the number of drainage type barrels is increased.

The set temperature of the dehydration barrel is appropriately selected depending on the monomer composition of the acrylic rubber, the ash content, the water content, the operating conditions, etc., but is usually 60 to 150 ° C., preferably 70 to 140 ° C., more preferably 80 to 80 to It is in the range of 130 ° C. The set temperature of the dehydration barrel for dehydrating in the drained state is usually 60 to 120 ° C, preferably 70 to 110 ° C, and more preferably 80 to 100 ° C. The set temperature of the dehydration barrel for dehydration in the exhaust 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 after dehydration of the drainage type dehydration that squeezes water from the water-containing crumb is not particularly limited, but is usually 1 to 40% by weight, preferably 5 to 40% by weight, more preferably 5 to 35% by weight, and particularly. When it is preferably 10 to 35% by weight, productivity and ash removal efficiency are highly balanced and preferable.

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

In the case of providing the drainage type dehydration barrel and the exhaust steam type dehydration barrel, the water content after drainage in the drainage type dehydration barrel portion is usually 5 to 40% by weight, preferably 10 to 40% by weight, more preferably. Is 15 to 35% by weight, and the water content after pre-drying in the exhaust steam type dehydration barrel portion is usually 1 to 30% by weight, preferably 3 to 20% by weight, and more preferably 5 to 15% by weight.

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

(Drying of hydrous crumbs in the drying barrel)
It is desirable that the water-containing crumb after dehydration is dried in the drying barrel portion under reduced pressure by a screw type twin-screw extrusion dryer having a drying barrel portion. By drying the acrylic rubber under reduced pressure, the production efficiency of drying is improved, and the air contained in the acrylic rubber is removed to produce an acrylic rubber veil having a high specific density and excellent storage stability, which is suitable. In the present invention, the storage stability can be highly enhanced by melting the acrylic rubber under reduced pressure and extruding and drying it. The storage stability of the acrylic rubber veil can be largely correlated with the specific gravity of the acrylic rubber veil and can be controlled, but when the specific gravity is large and a high degree of storage stability is controlled, it can be controlled by the degree of decompression of extrusion drying or the like.

The degree of decompression of the drying barrel may be appropriately selected, but when it is usually 1 to 50 kPa, preferably 2 to 30 kPa, more preferably 3 to 20 kPa, the water-containing crumb can be efficiently dried and the air in the acrylic rubber can be removed. It is suitable because it can be removed and the storage stability of the acrylic rubber veil can be significantly improved.

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 methyl ethyl ketone insoluble in the acrylic rubber veil can be reduced.

The number of drying barrels in the screw type twin-screw extruder is not particularly limited, but is usually a plurality, preferably 2 to 10, and more preferably 3 to 8. When there are a plurality of dry barrels, the degree of decompression may be an approximate degree of decompression for all the dry barrels, or may be changed. When there are a plurality of dry barrels, the set temperature may be an approximate temperature for all the dry 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 that the temperature of (1) is higher because the drying efficiency can be increased.

The water content of the dried rubber after drying is usually less than 1% by weight, preferably 0.8% by weight or less, and more preferably 0.6% by weight or less. In the present invention, the amount of methyl ethyl ketone insoluble in the acrylic rubber veil can be reduced by melt-extruding the dried rubber with the water content set to this value (with almost all water removed), especially in a screw-type twin-screw extruder. Suitable. In the present invention, an acrylic rubber bale that has been melt-kneaded or melt-kneaded and dried with a screw-type twin-screw extruder is suitable because both strength characteristics and Banbury processability characteristics are highly balanced. The term "melt kneading" or "melt kneading and drying" as used in the present invention means that acrylic rubber is kneaded (mixed) or extruded in a molten state in a screw type twin-screw extruder, and the stage thereof. It means that acrylic rubber is kneaded in a molten (plasticized) state by a screw-type twin-screw extruder and then extruded and dried.

In the present invention, the shear rate applied to the drying barrel of the screw type twin-screw extruder in a state where the acrylic rubber does not contain water is not particularly limited, but is usually 10 [1 / s]. As described above, the storage stability, roll workability, Banbury workability, and strength characteristics of the acrylic rubber veil obtained preferably in the range of 10 to 400 [1 / s], more preferably 50 to 250 [1 / s]. And the compression resistance permanent strain characteristics are highly balanced and suitable.

The shear viscosity of acrylic rubber in the screw type twin-screw extruder used in the present invention, particularly in a drying barrel, is not particularly limited, but is usually 12000 [Pa · s] or less, preferably 1000 to 12000 [Pa · s]. ], More preferably 2000 to 10000 [Pa · s], particularly preferably 3000 to 7000 [Pa · s], and most preferably 4000 to 6000 [Pa · s]. Stability, roll workability, Banbury workability and strength characteristics are highly balanced and suitable.

(Extrusion of dried rubber from the die part)
The dried rubber dehydrated and dried by the screw portion of the dehydration barrel and the dry barrel is sent to a rectifying die portion without a screw, and is extruded from the die portion into a desired shape. A breaker plate or wire mesh may or may not be provided between the screw portion and the die portion.

The extruded dry rubber is suitable because the die shape is made into a substantially rectangular shape and the die is formed into a sheet, so that air entrainment is small, the specific gravity is large, and the dry rubber is excellent in storage stability.

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, and more preferably 1 to 3 MPa, the amount of air entrained in the acrylic rubber veil is small ( It has a high specific gravity) and is excellent in productivity and suitable.

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

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

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

The rotation speed (N) of the screw type twin-screw extruder to be 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, most preferably. It is preferable that the water content of the acrylic rubber veil and the insoluble content of methyl ethyl ketone can be efficiently reduced at 120 to 300 rpm.

The extrusion amount (Q) of the screw type twin-screw extruder used is not particularly limited, but is usually 100 to 1,500 kg / hr, preferably 300 to 1200 kg / hr, more preferably 400 to 1000 kg / hr, and most. It is preferably 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 twin-screw extruder used is not particularly limited, but is usually 2 to 10, preferably 3 to 8. , More preferably in the range of 4-6.

The maximum torque of the screw type twin-screw extruder used is not particularly limited, but is usually 30 Nm or more, preferably 35 Nm or more, and more preferably 40 Nm or more. The maximum torque of the screw type twin-screw extruder used in the present invention is also usually in the range of 30 to 100 Nm, preferably 35 to 75 Nm, more preferably 40 to 60 Nm. It is suitable because it can highly balance the roll processability, bumper processability and strength characteristics of the manufactured acrylic rubber veil.

The specific power of the screw type twin-screw extruder used is not particularly limited, but is usually 0.1 to 0.25 [kW · h / kg] or more, preferably 0.13 to 0.23 [kW]. · H / kg], more preferably in the range of 0.15 to 0.2 [kW · h / kg], the roll workability, Banbury workability and strength characteristics of the acrylic rubber bale obtained are highly balanced. Suitable.

The specific power of the screw type twin-screw extruder used is not particularly limited, but is usually 0.2 to 0.6 [A · h / kg] or more, preferably 0.25 to 0.55 [A]. · H / kg], more preferably in the range of 0.35 to 0.5 [A · h / kg], the roll workability, Banbury workability and strength characteristics of the acrylic rubber veil obtained are highly balanced. Suitable.

The shear rate of the screw type twin-screw extruder used is not particularly limited, but is usually 40 to 150 [1 / s] or more, preferably 45 to 125 [1 / s], and more preferably 50 to 100. The storage stability, roll workability, Banbury workability and strength characteristics of the acrylic rubber veil obtained in the range of [1 / s] are highly balanced and suitable.

The shear viscosity of the acrylic rubber in the screw type twin-screw extruder used is not particularly limited, but is usually 4000 to 8000 [Pa · s] or less, preferably 4500 to 7500 [Pa · s], more preferably. The storage stability, roll workability, Banbury workability and strength characteristics of the acrylic rubber veil obtained in the range of 5000 to 7000 [Pa · s] are highly balanced and suitable.

As described above, in the present invention, it is preferable to use an extruder having a biaxial screw because dehydration, drying and molding can be performed under high share conditions.

(Sheet-shaped dry rubber)
The shape of the dried rubber extruded from the screw-type twin-screw extruder is sheet-like, and at this time, the specific gravity can be increased without entraining air, and the storage stability is highly improved, which is suitable. The sheet-shaped dry rubber extruded from the screw-type twin-screw extruder is usually cooled and cut to be used as the sheet-shaped acrylic rubber.

The thickness of the sheet-shaped dry rubber extruded from the screw-type twin-screw extruder is not particularly limited, but is usually 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 when it is within the range of. In particular, since the thermal conductivity of the sheet-shaped dried rubber is as low as 0.15 to 0.35 W / mK, the thickness of the sheet-shaped dried rubber is usually 1 to 30 mm when the cooling efficiency is increased and the productivity is significantly 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 twin-screw extruder is appropriately selected according to the purpose of use, but is usually in the range of 300 to 1200 mm, preferably 400 to 1000 mm, and more preferably 500 to 800 mm. ..

The temperature of the dried rubber extruded from the screw type twin-screw 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 dried rubber extruded from the screw type twin-screw extruder 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. ..

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

The sheet-shaped dry rubber extruded from the screw-type twin-screw extruder may be folded and used as it is, but usually it can be cut and used.

The cutting of the sheet-shaped dry rubber is not particularly limited, but since the acrylic rubber of the present invention has strong adhesiveness, the sheet-shaped dry rubber must be cooled before continuously cutting without entraining air. It is preferable to do it.

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

The complex viscosity ([η] 60 ° C.) of the sheet-shaped dried rubber at 60 ° C. is not particularly limited, but is usually 15,000 [Pa · s] or less, preferably 2000 to 10.000 [Pa · ·. s], more preferably 2500 to 7000 [Pa · s], and most preferably 2700 to 5500 [Pa · s], where air can be continuously cut without entrainment.

The ratio ([η] 100 ° C./[η] 60 ° C.) of the complex viscosity ([η] 100 ° C.) of the sheet-shaped dried rubber at 100 ° C. to the complex viscosity ([η] 60 ° C.) at 60 ° C. is There is no particular limitation and it may be appropriately selected according to the purpose of use, but it is usually 0.5 or more, preferably 0.6 or more, more preferably 0.7 or more, particularly preferably 0.8 or more, and most preferably. When it is 0.85 or more and the upper limit is usually 0.98 or less, preferably 0.97 or less, more preferably 0.96 or less, particularly preferably 0.95 or less, and most preferably 0.93 or less. It is suitable because it has little air entrainment and has a high balance between cutting and productivity.

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

In the air-cooling 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 is usually 40 ° C./hr or more, preferably 50 ° C./hr or more, more preferably 100 ° C./hr or more, and particularly preferably 150 ° C./hr or more. When it is, it is suitable because it can be easily cut and the storage stability can be improved without entraining air. In the present invention, the cooling rate of the sheet-shaped dry rubber is usually 40 ° C./hr or more, preferably 50 ° C./hr or more, more preferably 100 ° C./hr or more, and particularly preferably 150 ° C./hr or more. Sometimes the scorch stability when the acrylic rubber veil is made into a rubber composition is remarkably excellent and suitable.

The cutting length of the sheet-shaped dried rubber is not particularly limited and is appropriately selected according to the purpose of use, but is usually in the range of 100 to 800 mm, preferably 200 to 500 mm, and more preferably 250 to 450 mm.

The sheet-shaped acrylic rubber thus obtained is superior in operability as compared with crumb-shaped acrylic rubber, and is also excellent in roll workability, cross-linking property, strength property and compression set resistance, storage stability, Banbury workability and water resistance. It has excellent properties and can be used as it is or laminated and veiled.

(Laminating process)
The laminating temperature of the sheet-shaped dried rubber is not particularly limited, but is preferably 30 ° C. or higher, preferably 35 ° C. or higher, more preferably 40 ° C. or higher, because air entrained during laminating can be released. The number of 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 is integrated by the weight of the laminated sheet-shaped dry rubber (sheet-shaped acrylic rubber).

The acrylic rubber veil of the present invention thus obtained is superior in operability as compared with crumb-shaped acrylic rubber, and is excellent in roll workability, cross-linking property, strength property and compression set resistance permanent strain property, as well as storage stability, Banbury workability and It has excellent water resistance and can be used as it is or by cutting the required amount of acrylic rubber veil and putting it into a mixer such as a vanbury or roll.

<Rubber composition>
The rubber composition of the present invention is characterized by containing a rubber component including the acrylic rubber veil, a filler and a cross-linking agent.

As the rubber component which is the main component of the rubber composition of the present invention, the acrylic rubber veil of the present invention may be used alone, or, if necessary, the acrylic rubber veil of the present invention and other rubber components may be combined in combination. You may use it. The content of the acrylic rubber veil of the present invention in the rubber component may be selected according to the purpose of use, for example, usually 30% by weight or more, preferably 50% by weight or more, more preferably 70% by weight or more. ..

The other rubber components to be combined with the acrylic rubber veil of the present invention are not particularly limited, and are, for example, natural rubber, polybutadiene rubber, polyisoprene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, silicon rubber, fluororubber, and olefin. Examples thereof include based elastomers, styrene-based elastomers, vinyl chloride-based elastomers, polyester-based elastomers, polyamide-based elastomers, polyurethane-based elastomers, and polysiloxane-based elastomers.

These other rubber components can be used alone or in combination of two or more. The shape of these other rubber components may be any of a crumb shape, a strand shape, a veil shape, a sheet shape, a powder shape and the like. The content of other rubber components in the entire rubber component is appropriately selected within a range that does not impair the effects of the present invention, and is, for example, usually 70% by weight or less, preferably 50% by weight or less, and more preferably 30% by weight or less. ..

The filler contained in the rubber composition is not particularly limited, and examples thereof include a reinforcing filler and a non-reinforcing filler, and a roll of the rubber composition is preferably used when the filler is a reinforcing filler. It is suitable because it is excellent in workability, rubbery workability and short-time cross-linking property, and is highly excellent in water resistance, strength property and compression set resistance property of the crosslinked product.

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

These fillers can be used alone or in combination of two or more, and the blending amount thereof is appropriately selected within a range not impairing the effect of the present invention, and is usually used with respect to 100 parts by weight of the rubber component. It is 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 used in the rubber composition is not particularly limited, and a conventionally known cross-linking agent is selected according to the purpose of use. Examples thereof include inorganic cross-linking agents such as sulfur compounds and organic cross-linking agents, which are preferable. Is an organic cross-linking agent. The cross-linking agent may be either a polyvalent compound or a monovalent compound, but a polyvalent compound having two or more reactivity is preferable. The cross-linking agent may be either an ionic cross-linking compound or a radical cross-linking compound, but is preferably an ionic cross-linking compound.

The organic cross-linking agent is not particularly limited, but an ion-crosslinkable organic compound is preferable, and a polyvalent ion-organic compound is particularly preferable. When the cross-linking agent is a polyvalent ion organic compound (polyvalent ion cross-linking compound), the rubber composition is excellent in roll processability, Banbury processability and short-time cross-linking property, and the water resistance and strength of the cross-linked product are excellent. It is particularly suitable because of its excellent characteristics and compression resistance permanent strain characteristics. The "ion" of the ionic crosslinkable or polyvalent ion is an ionic reactive ion, and is particularly special as long as it ionically reacts with the ionic reactive group of the ionic reactive group-containing monomer of the acrylic rubber. Although not limited, preferably, an ion crosslinkable organic compound having an ionic reactive group such as an amine group, an epoxy group, a carboxyl group and a thiol group can be mentioned.

Specific examples of the polyvalent ion organic compound include a polyvalent amine compound, a polyvalent epoxy compound, a polyvalent carboxylic acid compound, a polyvalent thiol compound, and the like, preferably a polyvalent amine compound and a polyvalent thiol compound, more preferably. Is a polyvalent amine compound.

Examples of the polyvalent amine compound include aliphatic polyvalent amine compounds such as hexamethylenediamine, hexamethylenediamine carbamate, N, N'-dicinnamylidene-1,6-hexanediamine; 4,4'-methylenedianiline, p. -Phenylenediamine, m-Phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-Diaminodiphenyl ether, 4,4'-(m-Phenylenediisopropylidene) dianiline, 4,4'-(p-Phenylenedi) Isopropyridene) dianiline, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 4,4'-diaminobenzanilide, 4,4'-bis (4-aminophenoxy) biphenyl, m-xyli Aromatic polyvalent amine compounds such as range amines, p-xylylene diamines, 1,3,5-benzenetriamines; and the like. Among these, hexamethylenediamine carbamate, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane and the like are preferable. As the polyvalent amine compound, these carbonates can also be preferably used. These polyvalent amine compounds are particularly preferably used in combination with a carboxyl group-containing acrylic rubber veil or an epoxy group-containing acrylic rubber veil.

As the polyvalent thiol compound, a triazine thiol compound is preferably used, for example, 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, Examples thereof include 1-hexylamino-3,5-dimercaptotriazine. These triazine thiol compounds are particularly preferably used in combination with an acrylic rubber veil containing a chlorine atom.

Examples of other polyvalent organic compounds include polyvalent carboxylic acid compounds such as tetradecanedioic acid and dithiocarbamate metal salts such as zinc dimethyldithiocarbamate. These other polyvalent organic compounds are particularly preferably used in combination with an epoxy group-containing acrylic rubber veil.

These cross-linking agents can be used individually or in combination of two or more, and the blending amount thereof is usually 0.001 to 20 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the rubber component. Parts, more preferably 0.1 to 5 parts by weight. By setting the blending amount of the cross-linking agent in 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.

The rubber composition of the present invention can be blended with an antiaging agent as needed. The type of antiaging agent is not particularly limited, but is, for example, 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) Other phenolic antioxidants such as phenol; Tris ( Nonylphenyl) Phosphite, diphenylisodecylphosphite, tetraphenyldipropylene glycol / diphosphite and other phosphite-based anti-aging agents; sulfur ester-based antiaging agents such as dilauryl thiodipropionate; phenyl-α-naphthylamine, phenyl -Β-naphthylamine, p- (p-toluenesulfonylamide) -diphenylamine, 4,4'-(α, α-dimethylbenzyl) diphenylamine, N, N-diphenyl-p-phenylenediamine, N-isopropyl-N'- Amine-based antioxidants such as phenyl-p-phenylenediamine, butylaldehyde-aniline condensates; imidazole-based antioxidants such as 2-mercaptobenzimidazole; 6-ethoxy-2,2,4-trimethyl-1,2- Examples thereof include quinoline-based antioxidants such as dihydroquinoline; and hydroquinone-based antioxidants such as 2,5-di- (t-amyl) hydroquinone; and the like. Among these, amine-based antiaging 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 0.1 to 100 parts by weight with respect to 100 parts by weight of the rubber component. It is in the range of 10 parts by weight, more preferably 1 to 5 parts by weight.

The rubber composition of the present invention contains the above-mentioned rubber component containing the acrylic rubber veil of the present invention, a filler and a cross-linking agent as essential components, and if necessary, an anti-aging agent, and further, if necessary, the relevant technical field. Other additives commonly used in, such as cross-linking aids, cross-linking accelerators, cross-linking retarders, silane coupling agents, plasticizers, processing aids, rubbers, pigments, colorants, antioxidants, foaming agents. Etc. can be arbitrarily mixed. These other compounding agents can be used alone or in combination of two or more, and the compounding amount thereof is appropriately selected as long as the effect of the present invention is not impaired.

Examples of the method for producing the rubber composition of the present invention include a method of mixing the rubber component containing the acrylic rubber veil of the present invention, a filler, a cross-linking agent, and an antiaging agent and other compounding agents which can be contained as needed. For mixing, any means used in the conventional rubber processing field, for example, an open roll, a Banbury mixer, various kneaders and the like can be used. The mixing procedure of each component may be carried out by a normal procedure performed in the field of rubber processing. For example, a component that is difficult to react or decompose by heat is sufficiently mixed, and then a component that easily reacts or decomposes by heat is used. It is preferable to mix a certain cross-linking agent or the like at a temperature at which reaction or decomposition does not occur in a short time.

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

The rubber crosslinked product of the present invention is formed by using the rubber composition 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 is crosslinked by heating. It can be produced by carrying out a reaction and fixing the shape as a rubber crosslinked product. In this case, cross-linking may be performed after molding in advance, or cross-linking may be performed at the same time as molding. The molding temperature is usually 10 to 200 ° C, preferably 25 to 150 ° C. The crosslinking temperature is usually 100 to 250 ° C., preferably 130 to 220 ° C., more preferably 150 to 200 ° C., and the crosslinking 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, size, etc. 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 rubber crosslinked product of the present invention has excellent compression-resistant permanent strain resistance and water resistance while maintaining basic rubber properties such as tensile strength, elongation, and hardness.

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 seal, mechanical seal, well head seal, seal for electric / electronic equipment, air compression equipment. Sealing material such as seals; rocker cover gasket attached to the connection between the cylinder block and the cylinder head, oil pan gasket 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 the top cover 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 mold product and a mold cross-linked product for automobile applications, for example, fuel oil for fuel tanks such as fuel hoses, filler neck hoses, bent hoses, paper hoses, and oil hoses. It is suitably used for various hoses such as air hoses such as system hoses, turbo air hoses and mission control hoses, radiator hoses, heater hoses, brake hoses and air conditioner hoses.

<Device configuration used to manufacture acrylic rubber veils>
Next, an apparatus configuration used for manufacturing acrylic rubber 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, and a screw type twin-screw extruder.

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 has, 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 and emulsified while being appropriately stirred with a stirrer, and a redox catalyst consisting of an inorganic radical generator and a reducing agent is present. An emulsion polymerization reaction can be started below, and a chain transfer agent can be added in batches during the polymerization to obtain an emulsion polymerization solution. 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 processing related to the above-mentioned coagulation step. As schematically shown in FIG. 1, the coagulation device 3 includes, for example, a stirring tank 30, a heating unit 31 for heating the inside of the stirring tank 30, and a temperature control unit (not shown) for controlling the temperature inside the stirring tank 30. It has a stirring device 34 including a motor 32 and a stirring blade 33, and a drive control unit (not shown) that controls the rotation speed and rotation speed of the stirring blade 33. In the coagulation apparatus 3, a hydrous crumb can be generated by bringing the emulsion polymerization solution obtained by the emulsion polymerization reactor into contact with the coagulation solution and coagulating it.

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

The heating unit 31 of the coagulation device 3 is configured to heat the coagulation liquid filled in the stirring tank 30. Further, the temperature control unit of the coagulation device 3 controls the temperature inside the stirring tank 30 by controlling the heating operation by the heating unit 31 while monitoring the temperature inside the stirring tank 30 measured by the thermometer. It is configured. The temperature of the coagulating liquid in the stirring tank 30 is controlled by the temperature control unit 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 coagulating device 3 is configured to stir the coagulating liquid filled in the stirring tank 30. Specifically, the stirring device 34 includes a motor 32 that generates rotational power, and a stirring blade 33 that extends in a direction perpendicular to the rotation axis of the motor 32. The stirring blade 33 can flow the coagulating liquid by rotating around the rotation axis by the rotational power of the motor 32 in the coagulating liquid filled in the stirring tank 30. The shape and size of the stirring blade 33, the number of installations, and the like are not particularly limited.

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

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

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. Ru.

The water-containing crumb washed by the washing device 4 is supplied to the screw type twin-screw extruder 5 that performs the dehydration step and the drying step. At this time, it is preferable that the water-containing crumb after washing is supplied to the screw type twin-screw 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 twin-screw 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 twin-screw extruder 5 is set to 60 ° C. or higher. It may be possible to maintain it, and even if it is heated so that the temperature of the water-containing crumb is 40 ° C. or higher, preferably 60 ° C. or higher when it is transferred from the cleaning device 4 to the screw type twin-screw extruder 5. good. 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 twin-screw 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 twin-screw extruder 5 is shown in FIG. 1 as a suitable example, a centrifuge, a squeezer, or the like may be used as the dehydrator for performing the treatment related to the dehydration step, and the drying step may be performed. A hot air dryer, a vacuum dryer, an expander dryer, a kneader type dryer, or the like may be used as the dryer for performing the above treatment.

The screw type twin-screw 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 twin-screw 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 function as a dryer for drying the hydrous crumb. The drying 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 twin-screw extruder 5.

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

The screw-type twin-screw extruder 5 shown in FIG. 2 is a twin-screw-type extruder / dryer provided with a pair of screws (not shown) in the barrel unit 51. The screw type twin-screw extruder 5 has a drive unit 50 that rotationally drives a pair of screws in the barrel unit 51. With this configuration, acrylic rubber can be dried with a high share, which is suitable. The drive unit 50 is attached to the upstream end (left end in FIG. 2) of the barrel unit 51. Further, the screw type twin-screw 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 dry barrel portion 54 has eight dry barrels, that is, a first dry barrel 54a, a second dry barrel 54b, a third dry barrel 54c, a fourth dry barrel 54d, and a fifth dry 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, in the screw type twin-screw extruder 5, the water-containing crumbs in the barrels 52a to 52b, 53a to 53c, 54a to 54h are individually heated by heating the barrels 52a to 52b, 53a to 53c, 54a to 54h individually. Each has a heating means (not shown) for heating to a predetermined 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 jacket formed in each barrel 52a to 52b, 53a to 53c, 54a to 54h. It is not limited to this. Further, the screw type twin-screw 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 dry barrels constituting each

barrel portion

52, 53, 54 in the barrel unit 51 is not limited to the mode shown in FIG. 2, and the acrylic rubber to be dried is not limited to the mode shown in FIG. The number can be set according to the water content of the water-containing crumb.

For example, the number of supply barrels installed in the supply barrel portion 52 is, for example, 1 to 3. Further, the number of dehydration barrels installed in the dehydration barrel portion 53 is preferably, for example, 2 to 10, and more preferably 3 to 6, because the water-containing crumbs of the adhesive acrylic rubber can be efficiently dehydrated. 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 drive means such as a motor housed in the drive 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, and may be any shape required for 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 water-containing crumb.

The first to third dehydration barrels 53a to 53c constituting the dehydration barrel portion 53 each have

dehydration slits

56a, 56b, 56c for discharging the water content of the water-containing crumb to the outside. A plurality of each

dehydration slit

56a, 56b, 56c is formed in each dehydration barrel 53a to 53c, respectively.

The slit widths, that is, the openings of the dehydration slits 56a, 56b, 56c may be appropriately selected according to the usage conditions, and are usually 0.01 to 5 mm, the loss of the water-containing crumb is small, and the water-containing crumb is dehydrated. It is preferably 0.1 to 1 mm, and more preferably 0.2 to 0.6 mm from the viewpoint that the above can be efficiently performed.

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 steam 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 the form of vapor 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 advisable 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 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, 58d for degassing, respectively. Vent pipes (not shown) are connected to the

vent openings

58a, 58b, 58c, and 58d, respectively.

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

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

Further, 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 temperature in all the dry barrels 54a to 54h may be an approximate value or may be different, but the upstream side (dehydration 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 53 side) because the drying efficiency is improved.

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

The water-containing crumb of acrylic rubber obtained through the cleaning step is supplied to the supply barrel portion 52 from the feed port 55. 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 plastically mixed to form a melt, which generates heat and is carried to the downstream side while raising the temperature. Then, the water contained in the melt of the acrylic rubber is vaporized, and the water (steam) is discharged to the outside through the vent pipes (not shown) connected to the

vent ports

58a, 58b, 58c, 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 and is supplied from the die 59. Extruded.

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

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

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

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 3 to. It is 8, and 4 to 6 are particularly preferable.

The maximum torque in the barrel unit 51 is not particularly limited, but is usually in the range of 30 to 100 Nm, preferably 35 to 75 Nm, and more preferably 40 to 60 Nm.

The specific power in the barrel unit 51 is not particularly limited, but is usually 0.1 to 0.25 [kW · h / kg] or more, preferably 0.13 to 0.23 [kW · h / kg]. More preferably, it is in the range of 0.15 to 0.2 [kW · h / kg].

The specific power in the barrel unit 51 is not particularly limited, but is usually 0.2 to 0.6 [A ・ h / kg] or more, preferably 0.25 to 0.55 [A ・ h / kg]. More preferably, it is in the range of 0.35 to 0.5 [A.h / kg].

The shear rate in the barrel unit 51 is not particularly limited, but is usually 40 to 150 [1 / s] or more, preferably 45 to 125 [1 / s], and more preferably 50 to 100 [1 / s]. The range.

The shear viscosity of the acrylic rubber in the barrel unit 51 is not particularly limited, but is usually 4000 to 8000 [Pa · s] or less, preferably 4500 to 7500 [Pa · s], and more preferably 5000 to 7000 [Pa · s]. s].

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

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

FIG. 3 shows the configuration of a transport type cooling device 60 suitable as the cooling device 6 shown in FIG. The transport type cooling device 60 shown in FIG. 3 is configured to cool by an air cooling method while transporting the sheet-shaped dry rubber 10 discharged from the discharge port of the die 59 of the screw type extruder 5. By using this 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 blows cold air to the conveyor 61 that conveys the sheet-shaped dry rubber 10 discharged from the die 59 of the screw type extruder 5 in the direction of arrow A in FIG. 3 and the sheet-shaped dry rubber 10 on the conveyor 61. It has a cooling means 65 for spraying.

The conveyor 61 has

rollers

62 and 63, and a conveyor belt 64 that is wound around the

rollers

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

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

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

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

The bale 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, a veil-shaped acrylic rubber 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 veil 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, a veil-shaped acrylic rubber 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 the cooled sheet-shaped dry rubber 16 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 on which the cut sheet-shaped dry rubbers 16 are laminated can be manufactured.

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

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. Unless otherwise specified, "parts", "%" and "ratio" in each example are based on weight. Various physical properties were evaluated according to the following methods.

[Monomer composition]
Regarding the monomer composition in acrylic rubber, the monomer composition of each monomer unit ^{in acrylic rubber was confirmed by 1} H-NMR, and the activity of the reactive group remained in acrylic rubber and each of them. The reactive group content was confirmed by the following 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 in the rubber was The amount used for each monomer was the same.

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

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

[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 are dimethylformamide as a solvent, lithium chloride at a concentration of 0.05 mol / L, and 37% concentrated hydrochloric acid at a concentration of 0.01%, respectively. It is an absolute molecular weight distribution focusing on the absolute molecular weight and the polymer region measured by the GPC-MALS method using the added solution.

The configuration of the gel permeation chromatography multi-angle light scattering photometer, which is this device, consists of a pump (LC-20ADOpt manufactured by Shimadzu Corporation), a differential refractometer (Optilab rEX Wyatt Technology) as a detector, and a multi-angle It consists of a light scattering detector (DAWN HELEOS, manufactured by Waitt Technology). 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 sorted by size 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 by measuring the dissolution time. The measurement conditions and measurement methods by the GPC layer device are as follows.

Column: TSKgel α-M 2 pieces (φ7.8 mm x 30 cm, manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Flow velocity: 0.8 ml / mm
Sample preparation: 5 ml of a solvent was added to 10 mg of a sample (acrylic rubber veil), and the mixture was gently stirred at room temperature (dissolution was visually confirmed). After that, filtration was performed using a 0.5 μm filter.

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

[Methyl ethyl ketone insoluble amount]
The amount (%) of the methyl ethyl ketone insoluble content of the acrylic rubber veil was the amount of the insoluble content in the 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.
Methyl ethyl ketone insoluble content (%) = 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.
The measured value obtained by the following measuring method is the density, but the density of water is 1 Mg / m ³ and the specific gravity is used. Specifically, the specific gravity of the rubber sample obtained according to the method A of JIS K6268 cross-linked rubber-density measurement is the mass divided by the capacity including the voids of the rubber sample, and is the JIS K6268 cross-linked rubber-density measurement. It is obtained by dividing the density of the rubber sample measured according to the method A by the density of water (when the density of the rubber sample is divided by the density of water, the numerical values are the same and the unit is lost). Specifically, the specific gravity of the rubber sample is determined based on the following procedure.
(1) A 2.5 g test piece is cut out from a rubber sample that has been allowed to stand at a standard temperature (23 ° C ± 2 ° C) for at least 3 hours, and a thin piece having a mass of less than 0.010 g is cut out from a hook on a chemical balance having an accuracy of 1 mg. Using nylon thread, suspend the test piece so that the bottom of the test piece is 25 mm above the distribution tray for the chemical balance, and measure the mass (m1) of the test piece twice up to mg in the air.
^{(2) Next, a 250 cm 3} volume beaker placed on a sorting dish for a chemical balance is filled with distilled water cooled to a standard temperature after boiling, and the test piece is immersed in the distilled water, and bubbles adhering to the surface of the test piece. Remove, observe the movement of the pointer of the balance for a few seconds, confirm that the pointer does not gradually touch due to convection, and measure the mass (m2) of the test piece in water twice in mg units.
(3) When the density ^{of the test piece is less than 1 Mg / m 3} (when the test piece floats in water), attach a weight to the test piece to check the mass (m3) of the weight in water and the test piece. And the mass (m4) of the weight is measured twice in mg units.
^{(4) For the specific gravity of the rubber sample, the density (Mg / m 3} ) is calculated based on the following formula using the average values of m1, m2, m3, and m4 measured above, and the calculated density is the water density (4). Divide by 1.00 Mg / m ³ ) to obtain.
(Density of rubber sample when no weight is used)
Density = m1 / (m1-m2)
(Density of rubber sample when using weight)
Density = m1 / (m1 + m3-m4)

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

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

[Complex viscosity]
The complex viscosity η is measured by measuring the temperature dispersion (40 to 120 ° C.) at a strain of 473% and 1 Hz using a dynamic viscous elasticity measuring device “Rubber Process Analyzer RPA-2000” (manufactured by Alpha Technology). The complex viscosity η at temperature was determined. 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.

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

[Crosslinkability]
The crosslinkability of the rubber sample is the rate of change between the breaking strength of the rubber crosslinked product subjected to secondary cross-linking for 2 hours and the breaking strength of the rubber cross-linked product subjected to 4 hours ((4 hour cross-linked rubber cross-linked product breaking strength / 2 hour cross-linking). The breaking strength of the crosslinked rubber product) × 100) was calculated and judged according to the following criteria.
⊚: Breaking strength change rate is less than 10% ×: Breaking strength change rate is 10% or more

[Roll workability]
The roll processability of the rubber sample was evaluated according to the following criteria by observing the roll wrapping property and the state of the rubber when the rubber sample was kneaded.
⊚: Easy to knead, easy to wrap around the roll, no separation from the roll, and smooth surface of the rubber composition after kneading 〇: Easy to knead, easy to wrap around the roll, from the roll No separation is seen, and a slight unevenness is seen on a part of the surface of the rubber composition after kneading. □: Easy kneading, excellent roll wrapping property, and surface of the rubber composition after kneading. △: Easy to knead, slightly inferior in roll wrapping property, and slightly rough surface of the rubber composition after kneading ×: Load is applied to kneading and roll wrapping property is also poor. thing

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

[Evaluation of storage stability]
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. It was evaluated by an index with 1 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 1 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

[Compression-resistant permanent strain characteristics]
The compression set resistance characteristic of the rubber sample was evaluated according to the following criteria by measuring the compression set rate after leaving the rubber crosslinked product of the rubber sample at 175 ° C. for 90 hours in a state of being compressed by 25% according to JIS K6262. ..
⊚: The compression set is less than 15% ×: The compression set is 15% or more.

[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 ⊚ when it was 10 MPa or more and × when it was less than 10 MPa.
(2) The 100% tensile stress was evaluated as ⊚ for 5 MPa or more and × for less than 5 MPa.
(3) The elongation at break was evaluated as ⊚ for 150% or more and × for less than 150%.

[Evaluation of variation in the amount of methyl ethyl ketone insoluble]
The variation in the amount of insoluble methyl ethyl ketone in the rubber sample was evaluated by measuring 20 points of insoluble methyl ethyl ketone arbitrarily selected from 20 parts (20 kg) of the rubber sample and evaluating based on the following criteria.
⊚: The average value of the measured 20 points of methyl ethyl ketone insoluble content was calculated, and all 20 measured points were included within the range of the average value ± 3. 〇: The average value of the measured 20 points of methyl ethyl ketone insoluble content. Was calculated, and all 20 points measured within the range of the average value ± 5 were included (in the range of the average value ± 3, even one point out of the measured 20 points deviates, but the range of the average value ± 5 All 20 points can be put inside)
×: The average value of the measured amounts of methyl ethyl ketone insoluble at 20 points was calculated, and even one of the 20 points measured from the range of the average value ± 5 deviated.

[Evaluation of processing stability by suppressing Mooney scorch]
The cooling rate of the sheet-shaped acrylic rubber extruded from the screw type twin-screw extruder described in Japanese Patent No. 6683189 and the Mooney scorch stability of the acrylic rubber composition were evaluated.

[Example 1]
As shown in Table 2-1 in a mixing container equipped with a homomixer, 46 parts of pure water, 4.5 parts of ethyl acrylate as a monomer component, 64.5 parts of n-butyl acrylate, and methoxyethyl acrylate as a monomer component. 29.5 parts, mono n-butyl fumarate, 1.5 parts, and 1.8 parts of octyloxydioxyethylene phosphate sodium salt as an emulsifier were charged and stirred to obtain a monomeric emulsion.

170 parts of pure water and 3 parts of the above-mentioned monomer emulsion were put into a polymerization reaction tank equipped with a thermometer and a stirrer, cooled to 12 ° C. under a nitrogen stream, and then ferrous sulfate 0. The polymerization reaction was started by charging 00033 parts, 0.02 part of sodium ascorbate, and 0.2 part of potassium persulfate as an inorganic radical generator. The temperature in the polymerization reaction tank was kept at 23 ° C., and the rest of the monomer emulsion was continuously added dropwise over 3 hours. After 120 minutes, 0.4 part of L-sodium ascorbate was added to continue the polymerization reaction, and when the polymerization conversion rate reached approximately 100%, hydroquinone as a polymerization terminator was added to carry out the polymerization reaction. The process 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 emulsion polymer solution obtained above is heated to 80 ° C. and continuously added to coagulate the polymer in 350 parts of a coagulation solution using magnesium sulfate as an agent to coagulate the polymer, and the crumb of acrylic rubber which is a coagulated product. 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 water-containing crumbs remained, and the mixture was stirred for 15 minutes to wash the hydrous crumbs, and then water was discharged, and 194 parts of hot water (70 ° C.) was discharged again. Was added and stirred for 15 minutes to wash the water-containing crumbs (total number of washings was 2). The washed water-containing crumb (water-containing crumb temperature 65 ° C.) was supplied to the screw-type twin-screw extruder 15, dehydrated and dried, and a sheet-shaped dry rubber having a width of 300 mm and a thickness of 10 mm was extruded. Next, the sheet-shaped dry rubber was cooled at a cooling rate of 200 ° C./hr by using a transport-type cooling device directly connected to the screw-type twin-screw extruder 15.

The screw type twin-screw dryer 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 consists of a barrel). The first dehydration barrel drains water, and the second and third dehydration barrels drain steam. The operating conditions of the screw type twin-screw extruder were as follows.

Moisture content:
Moisture content of the hydrous crumb after drainage in the first dehydration barrel: 20%
Moisture content of the hydrous crumb after steam exhaust in the third dehydration barrel: 10%
Moisture content of the hydrous crumb after drying in the 5th drying barrel: 0.4%
Rubber temperature:
-The temperature of the hydrous crumb supplied to the supply barrel: 65 ° C
-The temperature of the rubber discharged from the screw type twin-screw extruder: 140 ° C
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 dry 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
・ Decompression degree of dry barrel: 10 kPa
-Rubber extrusion amount from die: 700 kg / hr
-Resin pressure on the die: 2MPa
・ Maximum torque in screw type twin-screw extruder: 15N ・ m

The extruded sheet-shaped dry rubber was cooled to 50 ° C., cut with a cutter, and laminated to 20 parts (20 kg) before the temperature fell below 40 ° C. to obtain an acrylic rubber veil (A). .. Reactive group content, ash content, ash component content, methyl ethyl ketone insoluble content, pH, specific gravity, glass transition temperature (Tg), water content, molecular weight, molecular weight distribution, and 100 ° C. of the obtained acrylic rubber veil (A). And the complex viscosity at 60 ° C was measured and shown in Table 2-2. In addition, the storage stability test of the acrylic rubber veil (A) was performed to determine the water content change rate, and the results are shown in Table 2-2.

Next, using a Banbury mixer, 100 parts of the acrylic rubber veil (A) and the compounding agent A of "formulation 1" shown in Table 1 were added and mixed at 50 ° C. for 5 minutes (first stage mixing). The BIT at this time was measured to evaluate the Banbury workability of the acrylic rubber veil, and the results are shown in Table 2-2.
Next, the obtained mixture 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 composition. The roll workability at this time was evaluated and the results are shown in Table 2-2.

The obtained rubber composition was placed in a mold having a length of 15 cm, a width of 15 cm, and a depth of 0.2 cm, and pressed at 180 ° C. for 10 minutes while pressurizing at a press pressure of 10 MPa to perform primary cross-linking. 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 test piece having a size of 3 cm × 2 cm × 0.2 cm was cut out from the obtained sheet-shaped rubber crosslinked product, and water resistance, compression resistance permanent strain resistance and normal physical properties were evaluated. In addition, the normal physical properties of the sheet-shaped rubber crosslinked product obtained by performing the secondary cross-linking for another 2 hours were measured to evaluate the cross-linking property. The results are shown in Table 2-2.

[Example 2]
Add the emulsifier to 1.8 parts of nonylphenyloxyhexaoxyethylene phosphate sodium salt, the amount of potassium persulfate of the inorganic radical generator to 0.21 parts, and add the chain transfer agent n-dodecyl mercaptan for 50 minutes. The same procedure as in Example 1 was carried out except that the changes were made to 0.017 parts after 100 minutes, 0.017 parts after 100 minutes and 0.017 parts after 120 minutes, and acrylic rubber veil (B) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

[Example 3]
The monomer component is 48.25 parts of ethyl acrylate, 50 parts of n-butyl acrylate and 1.75 parts of mono-n-butyl fumarate, and the emulsifier is 1.8 parts of tridecyloxyhexaoxyethylene phosphate sodium salt. Further, the water-containing crumb after washing was dried to a water content of 0.4% using a hot air dryer at 160 ° C. to obtain a crumb-shaped acrylic rubber, and then filled in a 300 × 650 × 300 mm baler and charged at 3 MPa. Acrylic rubber bale (C) was obtained in the same manner as in Example 1 except that the acrylic rubber was compacted with pressure for 25 seconds to form a veil-shaped acrylic rubber. Each property of the acrylic rubber veil (C) was evaluated (the compounding agent was changed to "formulation 2"), and the results are shown in Table 2-2.

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

[Example 5]
Example 3 except that the monomer component is changed to 42.2 parts of ethyl acrylate, 35 parts of n-butyl acrylate, 20 parts of methoxyethyl acrylate, 1.5 parts of acrylonitrile and 1.3 parts of vinyl chloroacetate. In the same manner, an acrylic rubber veil (E) was obtained and each characteristic (the compounding agent was changed to "formulation 4") was evaluated. The results are shown in Table 2-2.

[Example 6]
The monomer component is 48.25 parts of ethyl acrylate, 50 parts of n-butyl acrylate and 1.75 parts of mono-n-butyl fumarate, and the emulsifier is 1.8 parts of tridecyloxyhexaoxyethylene phosphate sodium salt. Further, the water-containing crumb after washing was dried to a water content of 0.4% using a hot air dryer at 160 ° C. to obtain a crumb-shaped acrylic rubber, and then filled in a 300 × 650 × 300 mm baler and charged at 3 MPa. Acrylic rubber bale (F) was obtained in the same manner as in Example 2 except that the acrylic rubber was compacted with pressure for 25 seconds to form a veil-shaped acrylic rubber. Each property of the acrylic rubber veil (F) was evaluated (the compounding agent was changed to "formulation 2"), and the results are shown in Table 2-2.

[Example 7]
The same procedure as in Example 6 was carried out except that the monomer component was changed to 28 parts of ethyl acrylate, 38 parts of n-butyl acrylate, 27 parts of methoxyethyl acrylate, 5 parts of acrylonitrile and 2 parts of allylglycidyl ether, and acrylic rubber. A veil (G) was obtained and each characteristic (the compounding agent was changed to "formulation 3") was evaluated. The results are shown in Table 2-2.

[Example 8]
Example 7 except that the monomer component is changed to 42.2 parts of ethyl acrylate, 35 parts of n-butyl acrylate, 20 parts of methoxyethyl acrylate, 1.5 parts of acrylonitrile and 1.3 parts of vinyl chloroacetate. In the same manner, an acrylic rubber veil (H) was obtained and each characteristic (the compounding agent was changed to "formulation 4") was evaluated. The results are shown in Table 2-2.

[Example 9]
Examples except that the amount of potassium persulfate of the inorganic radical generator was changed to 0.22 part, and 0.025 part of the chain transfer agent n-dodecyl mercaptan was continuously added to the monomer emulsion and not added afterwards. In the same manner as in No. 8, an acrylic rubber veil (I) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

[Comparative Example 1]
The coagulation reaction was carried out by adding a 0.7% magnesium sulfate aqueous solution to the agitated emulsion polymerization solution (stirring number 100 rpm, peripheral speed 0.5 m / s) after the emulsion polymerization without adding a chain transfer agent. The same procedure as in Example 9 was carried out except that a crumb-shaped acrylic rubber was obtained without being veiled by a baler, and a crumb-shaped acrylic rubber (J) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

[Comparative Example 2]
The emulsifier was changed to 0.709 parts of sodium lauryl sulfate and 1.82 parts of polyoxyethylene dodecyl ether, and the coagulation reaction was carried out by the emulsion polymerization solution being stirred after the emulsion polymerization (stirring number 100 rpm, peripheral speed 0.5 m /). The operation of adding sodium sulfate to s), washing the water-containing crumb in the washing step by adding 194 parts of industrial water, stirring at 25 ° C. for 5 minutes in the coagulation tank, and then discharging the water from the coagulation tank 2 The same procedure as in Example 9 was carried out except that the process was carried out only once and the crumb-shaped acrylic rubber was obtained without being veiled by a baler, and the crumb-shaped acrylic rubber (K) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

From Table 2-1 and Table 2-2, GPC-MALS having at least one reactive group selected from the group consisting of the carboxyl group, epoxy group and chlorine atom of the present invention and using a dimethylformamide-based solvent as a developing solvent. It is made of acrylic rubber in which the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the absolute molecular weight distribution measured by the method is 3.4 or more, and the amount of methyl ethyl ketone insoluble is 50. Acrylic rubber veil (A) to (I) having a weight% or less and an ash content of 0.4% by weight or less have a highly balanced roll workability, solvent workability, water resistance and compression set resistance, and further. It can be seen that the normal physical properties including storage stability, cross-linking property, and strength characteristics are also remarkably excellent (Examples 1 to 9).

From Table 2-2, the acrylic rubber veil (A) to (I) and the crumb-shaped acrylic rubber (J) to (K) produced under the conditions of the Examples and Comparative Examples of the present application have a carboxyl group, an epoxy group and chlorine. Since it has a reactive group of any of the atoms and has a large weight average molecular weight (Mw), it can be seen that it is excellent in normal physical properties including crosslinkability, compression resistance permanent strain property and strength property (Examples 1 to 9 and). Comparative Examples 1 and 2). However, the crumb-shaped acrylic rubbers (J) to (K) are inferior in roll processability, Banbury processability, water resistance and storage stability (Comparative Example 1), and are also inferior in water resistance and storage stability (Comparative Example 1). Comparative example 2).

From Table 2-2, regarding the roll processability, when the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is large, it is preferably 3.4 or more, more preferably 3.7. As described above, it can be seen that the roll workability can be improved without impairing the strength characteristics when the value is 4 or more (comparison between Examples 1 to 9 and Comparative Example 2 and Comparative Example 1).

From Table 2-1 and Table 2-2, the acrylic rubber veil having excellent strength characteristics and excellent roll processability and having a wide Mw / Mn can be used for a specific amount of an inorganic radical generator and a chain transfer agent, particularly n-dodecyl mercaptan. It can be seen that it can be manufactured by using it (Examples 1 to 9). From Table 2-2, the amount of the inorganic radical generator used was reduced as compared with the continuous addition of n-dodecyl mercaptan (Example 9), and the batch was added without the initial addition of n-dodecyl mercaptan. It can be seen that the roll processability can be further improved without impairing the strength characteristics by the post-addition (Examples 1 to 8). This is because the length of one polymerized chain is extended by reducing the amount of the inorganic radical generator and not adding the chain transfer agent at the initial stage, and the high molecular weight component and low molecular weight are not clearly doubled in the GPC chart. By producing the components in a well-balanced manner, increasing the Mw and widening the Mw / Mn, the strength characteristics and the roll processability are highly balanced. Further, in order to efficiently spread Mw / Mn, the number of batch post-additions has a greater effect than the difference in the amount of batch post-additions of the chain transfer agent, and the number of batch post-additions has a greater effect. Mw / Mn is wider twice than three times (comparison between Examples 3 to 5 and Examples 6 to 8), but continuous addition of the chain transfer agent spreads Mw / Mn to some extent. It becomes limited (Example 9). Further, although not shown in Table 2-2, in the examples of the present application, the reducing agent sodium ascorbate was added 120 minutes after the start of polymerization, whereby the high molecular weight component of acrylic rubber could be easily generated. The effect of spreading Mw / Mn added after the chain transfer agent is increased. On the other hand, although not shown in Table 2-1 when polymerized using an organic radical generator, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) does not increase and the roll processing is performed. It was inferior in sex and was not preferable. Although not shown in Table 2-1 when the amount of the chain transfer agent added is excessive and Mw / Mn is expanded too much, for example, when the amount is 10 or more, the low molecular weight component increases and the strength characteristics tend to be inferior.

From Table 2-2, it can be seen that the Banbury processability correlates with the amount of methyl ethyl ketone insoluble in the acrylic rubber veil, and that the smaller the methyl ethyl ketone insoluble content, the better the Banbury processability of the acrylic rubber veil (Example 1). Comparison between 9 and Comparative Example 1). The amount of methyl ethyl ketone insoluble content in the acrylic rubber veil can be reduced by emulsion polymerization in the presence of a chain transfer agent (Examples 3 to 8 and Comparative Example 2), and in particular, the amount of methyl ethyl ketone insoluble content enhances the strength characteristics. Therefore, when the polymerization conversion rate is increased, the rate increases sharply. Therefore, it can be seen that the formation of the insoluble matter of methyl ethyl ketone can be suppressed in Examples 3 to 8 of the post-addition of the chain transfer agent in the latter half of the emulsion polymerization. The amount of methyl ethyl ketone insoluble in the acrylic rubber veil is further reduced by drying the hydrous crumb with a screw type twin-screw extruder, and the bumper workability of the manufactured acrylic rubber veil is greatly improved (). Comparison between Examples 1 and 2 and Examples 3 to 8). In the present invention, although not shown in this example, the amount of methylethylkeone insoluble content that rapidly increased by emulsion polymerization without adding a chain transfer agent (Comparative Example 1) is substantially in the screw type twin-screw extruder. By melt-kneading in a state where it does not contain water (water content less than 1% by weight), it disappears and the amount of variation in the insoluble matter of methyl ethyl ketone is almost eliminated, and the vanbury workability is greatly improved without impairing the strength characteristics of the acrylic rubber veil. I'm sure I can do it.

From Table 2-2, it can be seen that the acrylic rubber veils (A) to (I) of the present invention are overwhelmingly superior in terms of water resistance (comparison between Examples 1 to 9 and Comparative Examples 1 and 2). Looking at the effect of the difference in the reactive group on the water resistance in Examples 3 to 9 having the same ash content, the acrylic rubber veil (E, H, I) of Examples 5, 8 and 9 having a chlorine atom. It can be seen that the acrylic rubber veil (C, F) of Examples 3 and 6 having a carboxyl group and the acrylic rubber veil (D, G) of Reference Examples 4 and 7 having an epoxy group are twice as superior as those of the above. .. From Table 2-2, the total amount of phosphorus, magnesium, sodium, calcium and sulfur in the ash of the acrylic rubber veil (A) to (I) of the present invention and the acrylic rubbers (J) to (K) of the comparative example. It was found that the amount of elements exceeded 90% by weight, and the acrylic rubber veil was excellent in properties such as water resistance and mold releasability. In particular, as the ratio of phosphorus and magnesium in the ash increased, the water resistance became higher. It can be seen that the properties are improved (comparison between Examples 1 to 9 and Comparative Example 1).

From Table 2-2, acrylic rubber veils (A) to (I), which are excellent in such roll processability and Banbury processability and also have significantly excellent water resistance, are chain transfer agents using an inorganic radical generator. In the coagulation step of the emulsion-polymerized liquid obtained by continuously or batch-adding the mixture, the coagulation reaction is carried out by adding the coagulation liquid to the agitated coagulation liquid instead of adding the coagulation liquid to the emulsion polymerization liquid. Further, it can be seen that the production can be further preferably carried out by vigorously stirring the coagulant (stirring number 600 rpm / peripheral speed 3.1 m / s) and increasing the coagulant concentration of the agitated coagulant (Example 1). Comparison between ~ 9 and Comparative Example 1). As will be described later, this coagulation reaction produces hydrous crumbs focused on a small crumb diameter in the range of 710 μm to 4.75 mm, and the efficiency of removing emulsifiers and coagulants in the washing and dehydrating steps is overwhelmingly improved. However, the amount of ash in the acrylic rubber veil has been reduced and the water resistance has been greatly improved.

From Table 2-2, it can be seen that the water resistance is superior to that of the chlorine atom when it is a carboxyl group or an epoxy group among the reactive groups (Examples 3 to 4 and Examples 6 to 6). Comparison of 7 with Example 5 and Example 8).

From Table 2-2, regarding the water resistance, the acrylic rubber veils (A) to (B) dehydrated (squeezed out) the water-containing crumb before drying have significantly reduced ash content and water resistance. It can be seen that it has been improved (comparison between Examples 1 and 2 and Examples 3 to 9). Looking at the amount of components in the ash of the acrylic rubber veils (A) to (B), most of them are phosphorus (P) and magnesium (Mg), which are the coagulants of the sodium phosphate salt of the emulsifier. It is salt-exchanged with magnesium sulfate and is contained in the hydrous crumb as magnesium phosphate, and although it cannot be sufficiently removed in the washing process, it is presumed that it could be reduced by dehydration (squeezing). Further, it can be seen that the components in the ash content of the acrylic rubber veil, which are rich in phosphorus and magnesium, do not deteriorate the water resistance (comparison between Examples 1 to 9 and Comparative Example 1 and Comparative Example 2).

From Table 2-2, the acrylic rubber veils (A) to (I) of the present invention are excellent in roll workability, Banbury workability, water resistance and compression set resistance, and are also remarkably stable in storage. It turns out to be excellent (Examples 1 to 9). It can be seen that the storage stability of acrylic rubber is greatly related to the specific gravity of acrylic rubber, and that when the specific gravity is large, air is not entrained in the acrylic rubber and the storage stability is excellent (Examples 1 and 2). Comparison with Examples 3 to 9 and Comparative Examples 1 and 2). Acrylic rubber veils with a large specific density are laminated by compressing a crumb-shaped acrylic rubber with a baler to form a veil (Examples 3 to 9), and more preferably extruding into a sheet shape with a screw-type twin-screw extruder. It can be obtained by bale (Examples 1 and 2). In the present invention, in particular, an acrylic rubber veil obtained by laminating sheet-shaped acrylic rubber that has been melt-kneaded and dried under reduced pressure includes short-time crosslinkability, roll workability, compression-resistant permanent strain characteristics, and strength characteristics. It can be seen that the storage stability is remarkably improved without impairing the normal physical properties and water resistance (Examples 1 and 2). It can also be seen that the storage stability of the acrylic rubber veil is preferable when the amount of ash is small or the pH is in a specific range (Examples 1 to 9).

[Regarding the particle size of the produced hydrous crumb]
Regarding the hydrous crumbs produced in the solidification steps of Examples 1 to 9 and Comparative Example 1, (1) 710 μm to 6.7 mm (passes 6.7 mm without passing through 710 μm), and (2) 710 μm to 4.75 mm (710 μm). The ratio of (3) 710 μm to 3.35 mm (passing 3.35 mm without passing through 710 μm) to the total water-containing crumb amount was measured using a JIS sieve. The results are shown below.

Example 1: (1) 90% by weight, (2) 90% by weight, (3) 87% by weight
Example 2: (1) 92% by weight, (2) 91% by weight, (3) 89% by weight
Example 3: (1) 89% by weight, (2) 87% by weight, (3) 83% by weight
Example 4: (1) 91% by weight, (2) 90% by weight, (3) 83% by weight
Example 5: (1) 93% by weight, (2) 91% by weight, (3) 89% by weight
Example 6: (1) 95% by weight, (2) 89% by weight, (3) 80% by weight
Example 7: (1) 92% by weight, (2) 92% by weight, (3) 88% by weight
Example 8: (1) 94% by weight, (2) 93% by weight, (3) 87% by weight
Example 9: (1) 90% by weight, (2) 89% by weight, (3) 88% by weight
Comparative Example 1: (1) 15% by weight, (2) 1% by weight, (3) 0% by weight

From these results, the amount of ash remaining in the acrylic rubber veil differs depending on the size of the water-containing crumb generated in the solidification process, and the cleaning efficiency is high even though the specific proportions of (1) to (3) are large. It can be seen that the amount of ash is high, the amount of ash is reduced, and the water resistance is excellent (comparison between Examples 3 to 9 in Table 2-2 and Comparative Example 1). Further, the water-containing crumbs having a large specific ratio of (1) to (3) have a high ash removal rate at the time of 20% by weight dehydration, further reduce the ash content and significantly improve the water resistance of the acrylic rubber veil. (Comparison between Examples 1 and 2 and Examples 3 to 9).

For reference, the same procedure as in Comparative Example 1 was performed except that the emulsion polymerization solution was added to the coagulation solution in the coagulation step (Reference Example 1), and the emulsion polymerization solution was added to the coagulation solution to provide a coagulant for the coagulation solution. The same procedure as in Comparative Example 1 was carried out except that the concentration was changed from 0.7% by weight to 2% by weight (Reference Example 2), and the particle size ratio of the produced hydrous crumb and the amount of ash in the acrylic rubber were measured.

Reference example 1: (1) 90% by weight, (2) 55% by weight, (3) 22% by weight, ash content 0.55% by weight
Reference example 2: (1) 91% by weight, (2) 70% by weight, (3) 40% by weight, ash content 0.41% by weight

From these results, the amount of ash in the acrylic rubber was changed to a method in which the concentration of the coagulating liquid was increased (2%) in the coagulation reaction and the emulsion polymerization solution was added to the agitated coagulating liquid (Lx ↓). Moreover, the crumb diameter of the hydrous crumb generated by vigorous stirring of the coagulating liquid (stirring number 600 rpm / peripheral speed 3.1 m / s) can be focused in a specific range of 710 μm to 4.75 mm, and the cleaning efficiency with warm water and the cleaning efficiency by warm water can be achieved. The efficiency of removing emulsifiers and coagulants during dehydration is significantly improved, reducing the amount of ash in the acrylic rubber veil, and impairing properties such as crosslinkability, roll processability, compression set resistance, and normal physical properties including strength properties. It can be seen that the water resistance can be significantly improved without any problem (Examples 1 and 2). It has been confirmed that the presence or absence of the addition of the chain transfer agent has no effect on the particle size of the water-containing crumbs produced.

[Example 10]
As shown in Table 3-1 the monomer components are 74.5 parts of ethyl acrylate, 17 parts of n-butyl acrylate, 7 parts of methoxyethyl acrylate, 1.5 parts of mono-n-butyl fumarate and an emulsifier. In the same manner as in Example 2 except that 1.8 parts of tridecyloxyhexaoxyethylene phosphate sodium salt was changed to obtain acrylic rubber (L), each characteristic was evaluated, and the results are shown in Table 3. Shown in -2. Table 3-1 shows the water content, maximum torque, specific power, specific power, shear rate and shear viscosity of the screw type twin-screw extruder after dehydration (drainage).

[Example 11]
The monomer component is 74.5 parts of ethyl acrylate, 17 parts of n-butyl acrylate, 7 parts of methoxyethyl acrylate, 1.5 parts of mono n-butyl fumarate, and the emulsifier is tridecyloxyhexaoxyethylene phosphate. The procedure was the same as in Example 1 except that the sodium salt was changed to 1.8 parts, acrylic rubber (M) was obtained, each characteristic was evaluated, and the results are shown in Table 3-2. Table 3-1 shows the water content, maximum torque, specific power, specific power, shear rate and shear viscosity of the screw type twin-screw extruder after dehydration (drainage).

[Example 12]
The monomer component is 28 parts of ethyl acrylate, 38 parts of n-butyl acrylate, 27 parts of methoxyethyl acrylate, 5 parts of acrylonitrile and 2 parts of allylglycidyl ether, and the operating conditions of the screw type twin-screw extruder are high. The procedure was the same as in Example 10 except that the share (maximum torque was changed to 45 Nm), acrylic rubber (N) was obtained, each characteristic (the compounding agent was changed to "formulation 3") was evaluated, and they were evaluated. The results are shown in Table 3-2. Table 3-1 shows the water content, maximum torque, specific power, specific power, shear rate and shear viscosity of the screw type twin-screw extruder after dehydration (drainage).

[Example 13]
Acrylic rubber (O) was carried out in the same manner as in Example 12 except that the monomer component was changed to 48.5 parts of ethyl acrylate, 50 parts of n-butyl acrylate and 1.5 parts of mono-n-butyl fumarate. Each characteristic (the compounding agent was changed to "formulation 1") was evaluated, and the results are shown in Table 3-2. Table 3-1 shows the water content, maximum torque, specific power, specific power, shear rate and shear viscosity of the screw type twin-screw extruder after dehydration (drainage).

[Example 14]
The same procedure as in Example 12 was carried out except that the monomer component was changed to 48.25 parts of ethyl acrylate, 50 parts of n-butyl acrylate and 1.75 parts of n-butyl fumarmonoate, and acrylic rubber (P) was added. Each characteristic (the compounding agent was changed to "formulation 2") was evaluated, and the results are shown in Table 3-2. Table 3-1 shows the water content, maximum torque, specific power, specific power, shear rate and shear viscosity of the screw type twin-screw extruder after dehydration (drainage).

[Example 15]
The monomer component is 28 parts of ethyl acrylate, 38 parts of n-butyl acrylate, 27 parts of methoxyethyl acrylate, 5 parts of acrylonitrile and 2 parts of allylglycidyl ether, and the operating conditions of the screw type twin-screw extruder are high. The procedure was the same as in Example 11 except that the share (maximum torque was changed to 45 Nm), acrylic rubber (Q) was obtained, each characteristic (the compounding agent was changed to "formulation 3") was evaluated, and they were evaluated. The results are shown in Table 3-2. Table 3-1 shows the water content, maximum torque, specific power, specific power, shear rate and shear viscosity of the screw type twin-screw extruder after dehydration (drainage).

[Example 16]
Acrylic rubber (R) was carried out in the same manner as in Example 15 except that the monomer component was changed to 48.5 parts of ethyl acrylate, 50 parts of n-butyl acrylate and 1.5 parts of mono-n-butyl fumarate. Each characteristic (the compounding agent was changed to "formulation 1") was evaluated, and the results are shown in Table 3-2. Table 3-1 shows the water content, maximum torque, specific power, specific power, shear rate and shear viscosity of the screw type twin-screw extruder after dehydration (drainage).

[Example 17]
The same procedure as in Example 15 was carried out except that the monomer component was changed to 48.25 parts of ethyl acrylate, 50 parts of n-butyl acrylate and 1.75 parts of mono-n-butyl fumarate, and the acrylic rubber (S) was used. Each characteristic (the compounding agent was changed to "formulation 2") was evaluated, and the results are shown in Table 3-2. Table 3-1 shows the water content, maximum torque, specific power, specific power, shear rate and shear viscosity of the screw type twin-screw extruder after dehydration (drainage).

From Tables 3-1 and 3-2, the acrylic rubbers (N) to (S) of the present invention are in a normal state including Banbury workability, water resistance, storage stability, cross-linking property, compression set resistance property and strength property. It can be seen that the physical properties are excellent and the roll workability is remarkably improved (comparison between Examples 12 to 17 and Examples 10 to 11). This is because acrylic rubber consisting of a high molecular weight component and a low molecular weight component that has been emulsion-polymerized by adding a chain transfer agent is dried with a high share using a screw-type twin-screw extruder to further increase the molecular weight and molecular weight distribution. It becomes a balanced acrylic rubber and can significantly improve roll workability.

Furthermore, for each rubber sample, the variation in the amount of methyl ethyl ketone insoluble content was evaluated by the above-mentioned method. That is, the variation evaluation of the amount of insoluble methyl ethyl ketone in the rubber sample was evaluated by measuring the insoluble amount of methyl ethyl ketone at 20 points arbitrarily selected from 20 parts (20 kg) of the rubber sample and evaluating based on the above-mentioned criteria.

Using the acrylic rubber veils (L) to (S) obtained in Examples 10 to 17 and the crumb-shaped acrylic rubber (J) obtained in Comparative Example 1 as rubber samples, the variation in the amount of methyl ethyl ketone insoluble is evaluated. The results of the acrylic rubber veils (L) to (S) of Examples 10 to 17 according to the present invention were all "◎", but the result of the crumb-shaped acrylic rubber (J) of Comparative Example 1 was ". It was "x".

This is because the acrylic rubber veils (L) to (S) are melt-kneaded in a screw-type twin-screw extruder and dried by melting-kneading and drying in a state where there is virtually no water content (water content less than 1% by weight). As a result, the amount of insoluble methyl ethyl ketone is almost eliminated and the amount of insoluble methyl ethyl ketone is almost eliminated, so that the vanbury workability can be improved without impairing the normal physical properties including crosslinkability, roll processability, compression resistance permanent strain property and strength property. It is presumed that it was significantly improved.

On the other hand, the hydrous crumb produced after performing emulsion polymerization and solidification washing under the conditions for producing the crumb-shaped acrylic rubber (J) of Comparative Example 1 is put into a screw type twin-screw extruder under the same conditions as in Example 10. It was found that the variation in the amount of methyl ethyl ketone insoluble and the amount of methyl ethyl ketone insoluble measured for the acrylic rubber obtained by extrusion drying was almost the same as that of the acrylic rubber veil (L), and the Banbury processability was also improved. Gender remained an "x" rating.

For the acrylic rubber compositions containing the acrylic rubber veils (L) to (S) of Examples 10 to 17, the Mooney scorch time t5 (minutes) at a temperature of 125 ° C. was set by the above-mentioned method for evaluating the processing stability by suppressing Mooney scorch. Measurements were made according to JIS K 6300, and Mooney Scorch storage stability was evaluated according to the following criteria. As a result, all of them were good results of "◎".
⊚: Mooney scorch time t5 exceeds 2.0 minutes 〇: Mooney scorch time t5 is 1.5 to 2.0 minutes ×: Mooney scorch time t5 is less than 1.5 minutes These acrylics Regarding the rubber veil (L) to (S), the cooling rate of the sheet-shaped dry rubber extruded from the screw type twin-screw extruder is as fast as about 200 ° C./hr as in Example 1, and both are as fast as 40 ° C./hr or more. Is.

[Releasability to mold]
The rubber compositions of the acrylic rubber veil (L) to (S) obtained in Examples 10 to 17 are press-fitted into a mold having a size of 10 mmφ × 200 mm, and the rubber crosslinked product after cross-linking at a mold temperature of 165 ° C. for 2 minutes is obtained. When the mold was taken out and the mold releasability was evaluated according to the following criteria, all of the acrylic rubber veils (L) to (S) were evaluated as "◎", which was a good evaluation.
◎: Easy to release from the mold and no mold residue 〇: Easy to release from the mold but only a small amount of mold residue is observed △: Easy to release from the mold but there is a small amount of mold residue ×: Difficult to remove from the mold

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

Claims

It has at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom, and has a weight average molecular weight (Mw) of an absolute molecular weight distribution measured by the GPC-MALS method using a dimethylformamide-based solvent as a developing solvent. ) And the ratio (Mw / Mn) of the number average molecular weight (Mn) is 3.4 or more, and the methyl ethyl ketone insoluble content is 50% by weight or less and the ash content is 0.4% by weight or less. A certain acrylic rubber veil.
The acrylic rubber veil according to claim 1, wherein the amount of methyl ethyl ketone insoluble is 10% by weight or less.
The acrylic rubber veil according to claim 1 or 2, wherein the values obtained by measuring the insoluble amount of methyl ethyl ketone at 20 points are all within the range of (average value ± 5)% by weight.
The acrylic rubber veil according to any one of claims 1 to 3, which has a specific gravity of 0.8 or more.
The acrylic rubber veil according to any one of claims 1 to 4, wherein the ash content is in the range of 0.001 to 0.2% by weight.
The acrylic rubber veil according to any one of claims 1 to 5, wherein the total amount of sodium, magnesium, calcium, phosphorus and sulfur in the ash is 50% by weight or more.
The acrylic rubber veil according to any one of claims 1 to 6, wherein the total amount of magnesium and phosphorus in the ash is 50% by weight or more.
The acrylic rubber veil according to any one of claims 1 to 7, wherein the weight average molecular weight (Mw) of the absolute molecular weight measured by the GPC-MALS method is 1 million or more.
Any one of claims 1 to 8 in which the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the absolute molecular weight distribution measured by the GPC-MALS method is 3.5 or more. Acrylic rubber veil as described in the section.
Any one of claims 1 to 8 in which the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the absolute molecular weight distribution measured by the GPC-MALS method is 3.8 or more. Acrylic rubber veil as described in the section.
Any one of claims 1 to 10 in which the ratio (Mz / Mw) of the z average molecular weight (Mz) and the weight average molecular weight (Mw) of the absolute molecular weight distribution measured by the GPC-MALS method is 1.3 or more. Acrylic rubber veil as described in the section.
The acrylic rubber veil according to any one of claims 1 to 11, wherein the acrylic rubber is emulsion-polymerized using a phosphate ester salt or a sulfate ester salt as an emulsifier.
13. Acrylic rubber veil.
The acrylic rubber veil according to any one of claims 1 to 13, wherein the acrylic rubber is melt-kneaded and dried after solidification.
The acrylic rubber veil according to claim 14, wherein the melt kneading and drying were carried out in a state of substantially no moisture.
The acrylic rubber veil according to claim 14 or 15, wherein the melt kneading and drying were performed under reduced pressure.
The acrylic rubber veil according to any one of claims 14 to 16, wherein the acrylic rubber is cooled at a cooling rate of 40 ° C./hr or more after the above-mentioned melt kneading and drying.
The acrylic rubber veil according to any one of claims 1 to 17, which is obtained by washing, dehydrating, and drying a water-containing crumb having a particle size in the range of 710 μm to 6.7 mm and having a proportion of 50% by weight or more.
Emulsion process in which an acrylic rubber monomer component containing a monomer containing at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom is emulsionized with water and an emulsifier. Inorganic radical generator In the presence of a redox catalyst containing a radical and a reducing agent, polymerization is started, a chain transfer agent is added in batches during the polymerization, and the polymerization is continued to obtain an emulsion polymerization solution.
A coagulation step of adding the obtained emulsion polymerization solution to the stirring coagulation liquid to coagulate and generate a hydrous crumb,
A cleaning process that cleans the generated hydrous crumb with warm water,
A dehydration process to dehydrate the washed water-containing crumbs,
A drying process that dries the dehydrated hydrous crumb to less than 1% by weight,
A veiling process for veiling dried dried rubber,
Manufacturing method of acrylic rubber veil including.
The method for manufacturing an acrylic rubber veil according to claim 19, wherein the acrylic rubber veil according to any one of claims 1 to 18 is manufactured.
The method for producing an acrylic rubber veil according to claim 19 or 20, wherein in the emulsion polymerization step, a phosphate ester salt or a sulfate ester salt is used as an emulsifier to carry out emulsion polymerization.
The acrylic rubber veil according to any one of claims 19 to 21, wherein the polymerization solution produced in the emulsion polymerization step is coagulated by using an alkali metal salt or a group 2 metal salt of the periodic table as a coagulant and dried. Manufacturing method.
The method for producing an acrylic rubber veil according to claim 22, wherein the polymerization solution produced in the emulsion polymerization step is added to an aqueous solution containing a coagulant containing an alkali metal salt or a metal salt of Group 2 of the periodic table and stirred to coagulate. ..
The method for producing an acrylic rubber veil according to any one of claims 19 to 23, wherein the polymerization liquid produced in the emulsion polymerization step is brought into contact with a coagulant to coagulate, and then melt-kneaded and dried.
The method for producing an acrylic rubber veil according to claim 24, wherein the melt kneading and drying are performed in a state where the moisture is substantially free.
The method for producing an acrylic rubber veil according to claim 24 or 25, wherein the melt kneading and drying are performed under reduced pressure.
The method for producing an acrylic rubber veil according to any one of claims 24 to 26, wherein the acrylic rubber after melt kneading and drying is cooled at a cooling rate of 40 ° C./hr or more.
The method for producing an acrylic rubber veil according to any one of claims 19 to 27, wherein a water-containing crumb having a particle diameter in the range of 710 μm to 6.7 mm and having a proportion of 50% by weight or more is washed, dehydrated, and dried.
A rubber composition comprising a rubber component containing the acrylic rubber veil according to any one of claims 1 to 18, a filler and a cross-linking agent.
The rubber composition according to claim 29, wherein the filler is a reinforcing filler.
The rubber composition according to claim 29, wherein the filler is carbon blacks.
The rubber composition according to claim 29, wherein the filler is silica.
The rubber composition according to any one of claims 29 to 32, wherein the cross-linking agent is an organic cross-linking agent.
The rubber composition according to any one of claims 29 to 33, wherein the cross-linking agent is a polyvalent compound.
The rubber composition according to any one of claims 29 to 34, wherein the cross-linking agent is an ionic cross-linking compound.
The rubber composition according to claim 35, wherein the cross-linking agent is an ionic cross-linking organic compound.
The rubber composition according to claim 35 or 36, wherein the cross-linking agent is a polyvalent ion organic compound.
At least one ionic reactive group in which the ion of the ionic crosslinkable compound, the ionic crosslinkable organic compound or the polyvalent ion organic compound as the crosslinking agent is selected from the group consisting of an amino group, an epoxy group, a carboxyl group and a thiol group. The rubber composition according to any one of claims 35 to 37.
The rubber composition according to claim 37, wherein the cross-linking agent is at least one polyvalent ion compound selected from the group consisting of a polyvalent amine compound, a polyvalent epoxy compound, a polyvalent carboxylic acid compound and a polyvalent thiol compound. ..
The rubber composition according to any one of claims 29 to 39, wherein the content of the cross-linking agent is in the range of 0.001 to 20 parts by weight with respect to 100 parts by weight of the rubber component.
The rubber composition according to any one of claims 29 to 40, further comprising an anti-aging agent.
The rubber composition according to claim 41, wherein the anti-aging agent is an amine-based anti-aging agent.
A method for producing a rubber composition in which a rubber component containing an acrylic rubber veil according to any one of claims 1 to 18, a filler and, if necessary, an antiaging agent are mixed, and then a cross-linking agent is mixed.
A rubber crosslinked product obtained by cross-linking the rubber composition according to any one of claims 29 to 42.
The rubber crosslinked product according to claim 44, wherein the cross-linking of the rubber composition is performed after molding.
The rubber crosslinked product according to claim 44 or 45, wherein the cross-linking of the rubber composition is for performing primary cross-linking and secondary cross-linking.