WO2021261216A1

WO2021261216A1 - Acrylic rubber bale having excellent banbury processability and injection moldability

Info

Publication number: WO2021261216A1
Application number: PCT/JP2021/021354
Authority: WO
Inventors: 浩文増田; 孝文川中
Original assignee: 日本ゼオン株式会社
Priority date: 2020-06-23
Filing date: 2021-06-04
Publication date: 2021-12-30
Also published as: CN116057073A; KR20230027027A; JPWO2021261212A1; WO2021261212A1; JPWO2021261215A1; JPWO2021261216A1; CN116034118A; KR20230027021A; KR20230026335A; CN116157424A; CN116113646A; WO2021261214A1; WO2021261215A1; KR20230027044A; JPWO2021261214A1

Abstract

Provided is an ancrylic rubber bale having excellent Banbury processability and injection moldability. An acrylic rubber bale according to the present invention is composed of acrylic rubber having at least one sort of reactive group selected from the group consisting of carboxyl groups, epoxy groups and chlorine atoms, wherein, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is in a range of 1.5 to 3, the gel content of a methyl ethyl ketone-insoluble fraction is 50 wt% or less, the ash content is 0.3 wt% or less, and the total content of sodium, sulfur, calcium, magnesium and phosphorus in the ash is 80 wt% or more.

Description

Acrylic rubber veil with excellent Banbury workability and injection moldability

The present invention relates to an acrylic rubber bale, a method for producing the same, a rubber composition and a crosslinked rubber, and more specifically, an acrylic rubber bale having excellent Banbury processability, injection moldability, strength characteristics, compression set resistance and water resistance. The present invention relates to a method for producing the same, a rubber composition containing the acrylic rubber veil, and a rubber crosslinked product obtained by cross-linking the rubber composition.

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 (Japanese Unexamined Patent Publication No. 11-12427) describes carbon-carbon double bonds such as ethyl acrylate, butyl acrylate, methoxyethyl acrylate, acrylonitrile, and allyl methacrylate and cyclopentenyloxyethyl acrylate. 100 parts of monomer component containing the monomer to be introduced into the chain, 4 parts of sodium lauryl sulfate, 0.25 part of p-menthane hydroperoxide as an organic radical generator, 0.01 part of ferrous sulfate, 0.025 parts of sodium ethylenediamine tetraacetate, 0.04 parts of sodium formaldehyde sulfoxylate, and 0.01 to 0.05 parts of t-dodecyl mercaptan as a chain transfer agent were charged into an autoclave substituted with nitrogen, and the reaction temperature was 30 ° C. The reaction was carried out until the conversion of the monomer mixture reached 100%, the obtained latex was added to a 0.25% aqueous solution of calcium chloride to coagulate, and the coagulated product was thoroughly washed with water at about 90 ° C. for 3 hours. Acrylic rubber and a cross-linking composition having excellent extrudability and scorch properties, which are dried and cross-linked with an organic peroxide such as 1,3-bis (t-butylperoxyisopropyl) benzene, are disclosed. However, the acrylic rubber obtained by this method has problems that the injection moldability and the Banbury processability are not sufficient, and the storage stability, the compression resistance permanent strain property, the water resistance and the strength property are inferior. Further, Patent Document 1 does not describe that acrylic rubber is veiled.

Further, Patent Document 2 (Japanese Unexamined Patent Publication No. 5-86137) discloses a method for producing acrylic rubber, in which polymerization is started with an organic radical generator, a chain transfer agent is added to a monomer emulsified solution, and the acrylic rubber is continuously administered. ing. Specifically, an appropriate amount of a monomer mixture containing crosslinkable monomers such as 2- (2-cyanoethoxy) ethyl acrylate, ethyl acrylate, n-butyl acrylate, and vinyl chloroacetate and allyl glycidyl ether. One-fifth of the mixture of n-dodecyl mercaptan is 1 part by weight of polyoxyethylene lauryl ether, 4 parts by weight of sodium lauryl sulfate, 0.7 part by weight of disodium hydrogen phosphate, and 0.3 part by weight of sodium dihydrogen phosphate. Mix and stir with half of the emulsion to make an emulsion, and after heating to 15 ° C, 0.005 part by weight of ethylene diamine tetraacetate sodium iron (II), 0.02 part by weight of ethylene diamine tetraacetate tetraacetic acid, and Longalit 0.02. 0.02 part by weight and 0.02 part by weight of sodium hydrosulfite were added, and a 0.2 wt% aqueous solution of tert-butyl hydroperoxide, which is an organic radical generator, was added dropwise at a rate of 1.5 parts per hour to initiate polymerization. While maintaining the temperature at 15 ° C., an emulsion consisting of a mixture of the remaining monomer and n-dodecyl mercaptan and an aqueous emulsifier was added dropwise over 3 hours to carry out a polymerization reaction with a monomer conversion rate of 96 to 99%. Further, the obtained copolymer latex can be put into an aqueous solution of calcium chloride at 85 ° C. to isolate the copolymer, thoroughly washed and then dried to obtain the desired copolymer rubber, which can be crosslinked with sulfur. Has been described. However, the acrylic rubber obtained by this method has problems that the injection moldability is not sufficient and the storage stability, water resistance and strength characteristics are inferior.

Further, Patent Document 3 (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, and dehydrating and drying with an extrusion dryer having a screw. However, the acrylic rubber obtained by this method has problems of inferior injection moldability, storage stability, and water resistance.

Further, Patent Document 4 (International Publication No. 2018/110703) is charged with a monomer component composed of ethyl acrylate and mono-n-butyl fumarate, water and sodium dodecyl sulfate, and is subjected to vacuum degassing and nitrogen substitution. After sufficiently removing oxygen by performing 3 degrees, azobis (isobutyronitrile) and ethyl-2-methyl-2-phenylteranylpropinate, which are organic radical generators, are added, and the temperature is 50 degrees under normal pressure. A method of initiating a polymerization reaction, polymerizing until the polymerization conversion rate reaches 89%, coagulating with a calcium chloride solution, washing with water, and drying to produce acrylic rubber is disclosed. However, the acrylic rubber obtained by this method has problems of inferior injection moldability, Banbury processability, storage stability, and water resistance.

As a method for producing an acrylic rubber using an inorganic radical generator, for example, Patent Document 5 (Japanese Unexamined Patent Publication No. 2019-11977) comprises ethyl acrylate, butyl acrylate, methoxyethyl acrylate and monobutyl maleate. After making a monomer emulsion using pure water, sodium lauryl sulfate and polyoxyethylene dodecyl ether as the monomer component as an emulsifier, a part of the monomer emulsion is put into a polymerization reaction tank and under a nitrogen stream. After cooling to 12 ° C., the remaining monomer emulsion, ferrous sulfate, sodium ascorbate and potassium persulfate aqueous solution as an inorganic radical generator are continuously added dropwise over 3 hours, and then. After the polymerization conversion rate reached 97% by weight, the temperature was raised to 85 ° C., and then sodium sulfate was continuously added to separate the water-containing crumbs by coagulation filtration. After the water-containing crumb was washed 4 times with water, 1 time with acid and 1 time with pure water, acrylic rubber was continuously produced into a sheet in an extrusion dryer having a screw, and a fat such as hexamethylene diamine carbamate was continuously produced. A method of cross-linking with a group polyvalent amine compound is disclosed. However, the sheet-shaped acrylic rubber obtained by this method has problems that it is inferior in injection moldability and storage stability, and that the water resistance of the crosslinked product is inferior.

Patent Document 6 (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 problems of inferior injection moldability, storage stability, and water resistance.

Patent Document 7 (Japanese Unexamined Patent Publication No. 62-64809) describes a compound of at least one of an acrylic acid alkyl ester and an acrylic acid alkoxyalkyl ester in an amount of 50 to 99.9% by weight, dihydrodicyclopentenyl as an unsaturated carboxylic acid. A copolymer having a monomer composition consisting of 0.1 to 20% by weight of a group-containing ester and 0 to 20% by weight of at least one of other monovinyl-based, monovinylidene-based and monovinylene-based unsaturated compounds. The number average molecular weight (Mn) in terms of polystyrene using tetrahydrofuran as a developing solvent is 200 to 1.2 million, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 10 or less. Acrylic rubber capable of sulfur sulfurization is disclosed. 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 regulator. 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. Acrylate rubber having a ratio (Mw / Mn) to (Mn) of 4.7 to 8 is disclosed. When the amount of the chain transfer agent is small, the number average molecular weight (Mw) is as large as 5 million and the ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) is as narrow as 1.4. When the amount of the chain transfer agent is large, the number average molecular weight (Mn) is as small as 200,000, and the ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) may be extremely wide as 17. Examples are shown in Comparative Examples. However, the acrylic rubber obtained by this method is inferior in injection moldability, and in the crosslinking reaction, sulfur as a crosslinking agent and a vulcanization accelerator are added and kneaded with a roll, and then in a vulcanization press at ^{100 kg / cm 2 170.} There is a problem that long-term cross-linking is required at ° C for 15 minutes and further at 175 ° C for 4 hours in a gear oven, and the obtained cross-linked product is inferior in water resistance, compression resistance permanent strain characteristics and strength characteristics, and There were problems such as inferior change in physical properties after thermal deterioration.

On the other hand, regarding the veiled acrylic rubber, for example, in Patent Document 8 (Japanese Unexamined Patent Publication No. 2006-328239), a crumb slurry containing a crumb-like rubber polymer is obtained by contacting the polymer latex with a coagulating liquid. A step of crushing the crumb-shaped rubber polymer contained in the crumb slurry with a mixer having a stirring / crushing function having a stirring power of 1 kW / m ^{3 or more, and a crumb slurry in which the crumb-shaped rubber polymer is crushed.} Disclosed is a method for producing a rubber polymer, which comprises a dehydration step of removing water from the material 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. , It is described that it is introduced into a baler in the form of flakes, 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, the acrylic rubber veil composed only of acrylate has a problem that the crosslinked rubber characteristics such as heat resistance and compression set resistance are inferior.

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 9 (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-solidified water-containing crumbs are generated in the coagulation reaction, which causes a large amount of adhesion to the coagulation tank, problems such as insufficient removal of coagulants and emulsifiers by washing, and acrylic rubber itself. It is inferior in injection moldability and emulsifier workability, and even if a bale is made, it cannot sufficiently remove air and is inferior in storage stability. There was a problem such as.

Regarding the amount of gel of acrylic rubber, for example, Patent Document 10 (Japanese Patent No. 3599962) contains radically reactive unsaturated groups having different reactivity from 95 to 99.9% by weight of alkyl acrylate or alkoxyalkyl acrylate. Acrylic rubber having a gel content of 5% by weight or less, which is an acetone-insoluble component obtained by copolymerizing 0.1 to 5% by weight of a polymerizable monomer having two or more in the presence of a radical polymerization initiator. Disclosed are acrylic rubber compositions which are composed of a reinforcing filler and an organic peroxide-based sulfide and have excellent extrusion processability such as extrusion speed, die well, and surface skin. The acrylic rubber having a very small gel content used here is an acrylic rubber having a high gel content (60%) obtained in a normal acidic region (prepolymerization pH 4, post-polymerization pH 3.4). On the other hand, it is obtained by adjusting the pH of the polymerization solution to 6 to 8 with sodium hydrogen carbonate or the like. Specifically, after adding water, sodium lauryl sulfate and polyoxyethylene nonylphenyl ether, sodium carbonate and boric acid as emulsifiers and adjusting the temperature to 75 ° C., t-butyl hydroperoxide and longalit, which are organic radical generators, are used. Ethylenediamine disodium tetraacetate and ferrous sulfate were added (pH at this time was 7.1), and then the monomer components of ethyl acrylate and allyl methacrylate were added dropwise to carry out emulsion polymerization, and the obtained emulsion ( pH7) is salted using an aqueous sodium sulfate solution, washed with water and dried to obtain an acrylic rubber. However, acrylic rubber containing (meth) acrylic acid ester as a main component decomposes in the neutral to alkaline region, and even if the processability is improved, there is a problem that the storage stability and strength characteristics are inferior, and the injection moldability is also good. There is also a problem that the Banbury processability, water resistance, cross-linking property and compression set resistance are inferior.

Further, in Patent Document 11 (International Publication No. 2018/143101 pamphlet), a (meth) acrylic acid ester and an ion-crosslinkable monomer are emulsion-polymerized and have a complex viscosity at 100 ° C. ([η] 100 ° C.). Is 3,500 Pa · s or less, and the ratio of the complex viscosity at 60 ° C. ([η] 60 ° C.) to the complex viscosity at 100 ° C. ([η] 100 ° C.) ([η] 100 ° C./[η] 60 Disclosed is a technique for improving the extrusion moldability, particularly the discharge amount, the discharge length and the surface texture of a rubber composition containing a reinforcing agent and a cross-linking agent by using acrylic rubber having a ° C.) of 0.8 or less. The amount of gel, which is a THF (tetrahydrofuran) insoluble component of acrylic rubber used in the same technique, is 80% by weight or less, preferably 5 to 80% by weight, and preferably exists as much as possible in the range of 70% or less. It is stated that when the amount of gel is less than 5%, the extrudability deteriorates. The weight average molecular weight (Mw) of the acrylic rubber used is 200,000 to 1,000,000, and when the weight average molecular weight (Mw) exceeds 1,000,000, the viscoelasticity of the acrylic rubber is high. It is stated that it is too much to be preferable. However, there is no description of a method for improving processability, strength characteristics, water resistance, etc. such as injection moldability and Banbury.

Japanese Unexamined Patent Publication No. 11-12427 Japanese Unexamined Patent Publication No. 2019-11977 International Publication No. 2019/188709 Pamphlet International Publication No. 2018/110703 Pamphlet Japanese Unexamined Patent Publication No. 2019-11977 Japanese Unexamined Patent Publication No. 1-135811 Japanese Unexamined Patent Publication No. 62-64809 Japanese Unexamined Patent Publication No. 2006-328239 International Publication No. 2018/116828 Pamphlet Japanese Patent No. 3599962 International Publication No. 2018/143101 Pamphlet

The present invention has been made in view of the actual conditions of the prior art, and is an acrylic rubber bale excellent in Banbury workability, injection moldability, strength characteristics, compression set resistance and water resistance, a method for producing the same, and the acrylic rubber. It is an object of the present invention to provide a rubber composition containing a veil and a rubber crosslinked product obtained by cross-linking the rubber composition.

As a result of diligent research in view of the above problems, the present inventors have at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom, and have a weight average molecular weight (Mw) and a number average molecular weight (Mw). It is made of acrylic rubber having a ratio (Mw / Mn) to Mn) in the range of 1.5 to 3, and the gel amount of the insoluble methyl ethyl ketone is 50% by weight or less, the ash content is 0.3% by weight or less, and the ash content is Acrylic rubber veil having a total amount of sodium, sulfur, calcium, magnesium and phosphorus of 80% by weight or more has excellent Banbury processability, injection moldability, strength characteristics, compression set resistance and water resistance. Found to be highly balanced.

The present inventors have found that the smaller the gel amount of the methyl ethyl ketone insoluble matter in the acrylic rubber veil, the better the Banbury processability. The amount of gel of the insoluble methyl ethyl ketone in the acrylic rubber veil is generated during the polymerization reaction of acrylic rubber, and in particular, when the polymerization conversion rate is increased in order to improve the strength characteristics, it rapidly increases and is difficult to control. It can be suppressed to some extent by emulsion polymerization in the presence of a chain transfer agent in the latter half of the polymerization reaction. It has been found that by melt-kneading and drying acrylic rubber, the amount of gel in which the methyl ethyl ketone is insoluble disappears and there is no variation, and the Banbury processability of the acrylic rubber veil can be significantly improved. The present inventors also have a screw-type twin-screw extruder, and the acrylic rubber veil manufactured by melt-kneading and drying with almost water removed has a high degree of Banbury workability without impairing the strength characteristics. I found that it could be improved.

In order to highly balance the injection moldability and strength characteristics of the acrylic rubber veil, the present inventors consider the weight average molecular weight (Mw), the weight average molecular weight (Mw), and the number average molecular weight (Mn) of the acrylic rubber. We have found that it is important to keep the ratio (Mw / Mn) in a specific region. In order to produce such acrylic rubber, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is narrow and injection moldability is achieved only by emulsion polymerization using an organic radical generator. Although inferior, it was found that this can be achieved by adding a chain transfer agent in batches during the polymerization. The injection moldability was remarkably excellent in all of the characteristics of shape forming property, fusion property and mold releasability. On the other hand, it was found that the acrylic rubber emulsion-polymerized using an inorganic radical generator has a too wide ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) and is inferior to injection molding.

The present inventors also dry the acrylic rubber by using a specific extrusion dryer, and by melt-kneading and drying the acrylic rubber under the optimum share conditions using the specific extrusion drying. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is widened without impairing the weight average molecular weight (Mw). We have found that an acrylic rubber veil with a highly balanced permanent strain characteristic can be manufactured.

The present inventors have an acrylic rubber veil having at least one reactive group consisting of a group consisting of a carboxyl group, an epoxy group and a chlorine atom, preferably an (meth) acrylic acid alkyl ester and a (meth) acrylic acid alkoxyalkyl. Acrylic rubber veil made of at least one (meth) acrylic acid ester selected from the group consisting of esters, acrylic rubber obtained by copolymerizing the reactive group-containing monomer and, if necessary, other monomers, is resistant to acrylic rubber veil. It was found that the normal physical properties including the compression set characteristics and the strength characteristics are highly balanced.

The present inventors copolymerize at least one reactive group consisting of the group consisting of such a carboxyl group, an epoxy group and a chlorine atom, or a monomer having a reactive group when they are an ionic reactive group. In the GPC measurement of the reactive acrylic rubber that reacts with the cross-linking agent or the like, the tetrahydrofuran used for the GPC measurement of the radically reactive acrylic rubber obtained by copolymerizing the ethyl acrylate and the dihydrodicyclopentenyl acrylate of the above-mentioned prior art can be sufficiently dissolved. 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 was possible to dissolve cleanly and measure with good reproducibility, and each characteristic value was specified. It was found that the injection moldability, solventy workability, strength characteristics, compression set resistance property and water resistance of the acrylic rubber veil can be highly controlled within the range.

The present inventors have found that the water resistance is greatly affected by the ash content and the ash content component in the acrylic rubber veil. In addition, reducing the amount of ash in the acrylic rubber veil is particularly difficult to remove ash from acrylic rubber produced using a large amount of emulsifier or coagulant, but the water-containing crumb produced in the coagulation process. It was found that by controlling the particle size of the acrylic rubber veil, the cleaning efficiency of the hydrous crumb and the ash removal efficiency at the time of dehydration can be remarkably improved, and the water resistance of the acrylic rubber veil can be remarkably improved. Further, the present inventors have not only the above-mentioned ash content and ash component amount, but also when a phosphate ester salt or a sulfate ester salt is used as an emulsifier, and / or an alkali metal salt or a Group 2 metal of the periodic table as a coagulant. It has been found that the water resistance of the acrylic rubber veil can be significantly improved and the injection moldability is also excellent when salt is used.

The present inventors also, after emulsifying a monomer component containing a specific reactive group-containing monomer with water and an emulsifier, a redox consisting of an organic radical generator such as diisopropylbenzenehydroperoxide and a reducing agent. Emulsion polymerization is started in the presence of a catalyst, and the emulsion polymerization is carried out by adding the chain transfer agent in batches during the polymerization without adding the chain transfer agent at the initial stage. By dehydrating, drying and molding with a specific screw type twin-screw extruder after cleaning the water-containing crumbs generated by solidification, injection moldability, Banbury workability, strength characteristics, compression permanent strain resistance and water resistance It was found that an excellent acrylic rubber veil can be efficiently produced.

The present inventors have also found that the larger the specific gravity of the acrylic rubber bale, the better the injection moldability, the Banbury workability, the strength property, the compression set resistance and the water resistance, and the storage stability is remarkably excellent. The acrylic rubber of the present invention, which has a specific ion-reactive group such as a carboxyl group, an epoxy group, and a chlorine atom, is adhesive and has a high affinity with air, so that once air is entrained, it is difficult to remove, and a water-containing crumb. The directly dried crumb-shaped acrylic rubber entrained a large amount of air (the specific gravity became smaller) and deteriorated the storage stability. The present inventors can remove some air and improve the storage stability of the acrylic rubber by compressing the crumb-shaped acrylic rubber with a high-pressure baler or the like to form a veil. We have found that it is possible to produce an acrylic rubber veil that is dried under reduced pressure and extruded into an air-free sheet by using a shaft extruder dryer to produce an acrylic rubber veil that contains almost no air (high specific gravity) and has extremely excellent storage stability. .. 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. The present inventors also have an acrylic rubber veil that has been dried under reduced pressure or melted and extruded under reduced pressure by a screw-type twin-screw extruder, and has characteristics of storage stability, injection moldability, and strength characteristics. We have found that it is particularly excellent and highly balanced.

The present inventors also have a monomer composition of acrylic rubber, a type of ionic reactive group, a molecular weight distribution focusing on a high molecular weight region (Mz / Mw), and a complex viscosity ratio at 100 ° C. ([η] 100. By specifying the ratio ([η] 100 ° C / [η] 60 ° C) between the complex viscosity ([η] 60 ° C) at 60 ° C (° C) and the water content, further, Banbury workability and injection moldability , Strength characteristics, compression set resistance, and water resistance have been found to be highly enhanced.

The present inventors have found that by using an ionic crosslinkable organic compound as a crosslinking agent, each property of a rubber crosslinked product having excellent crosslinkability and obtained is further improved.

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 Banbury processability, the injection moldability, and the short time can be shortened. 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, and for example, the ionic reactivity of acrylic rubber 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 groups, it is excellent in Banbury processability, injection moldability, short-time cross-linking property, and water resistance, strength characteristics and compression resistance permanent of the cross-linked product. We have found that the 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 a weight average molecular weight (Mw) to a number average molecular weight (Mn) ratio (Mw). / Mn) is made of acrylic rubber in the range of 1.5 to 3, the gel amount of methyl ethyl ketone insoluble content is 50% by weight or less, the ash content is 0.3% by weight or less, and sodium, sulfur, calcium in the ash content. , An acrylic rubber veil having a total amount of magnesium and phosphorus of 80% by weight or more is provided.

In the acrylic rubber veil of the present invention, the acrylic rubber is a bonding unit composed of at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester, carboxyl. It is preferably composed of a bonding unit consisting of at least one reactive group-containing monomer selected from the group consisting of a group, an epoxy group and a chlorine atom, and, if necessary, a bonding unit from another monomer. ..

In the acrylic rubber veil of the present invention, it is preferable that the values obtained by arbitrarily measuring the gel amount of the insoluble matter of methyl ethyl ketone at 20 points are all within the range of (average value ± 5)% by weight.

In the acrylic rubber veil of the present invention, the reactive group is preferably an ionic reactive group.

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

In the acrylic rubber veil of the present invention, the ratio (Mz / Mw) of the z average molecular weight (Mz) of the acrylic rubber to the weight average molecular weight (Mw) is preferably 1.3 or more.

In the acrylic rubber veil of the present invention, it is preferable that the solvent for measuring the molecular weight of the acrylic rubber is a dimethylformamide-based solvent.

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

In the acrylic rubber veil of the present invention, the water content is preferably less than 1% by weight.

The acrylic rubber veil of the present invention is preferably emulsion-polymerized using a phosphate ester salt or a sulfate ester salt as an emulsifier.

In the acrylic rubber veil of the present invention, it is preferable that the emulsion polymerized solution is coagulated by using an alkali metal salt or a metal salt of Group 2 of the periodic table as a coagulant and dried.

The acrylic rubber veil of the present invention is preferably melt-kneaded and dried after solidification.

According to the present invention, also from at least one (meth) acrylic acid ester, carboxyl group, epoxy group and chlorine atom selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester. An emulsion step of emulsifying a monomer component consisting of at least one reactive group-containing monomer selected from the above group and, if necessary, other monomers with water and an emulsifier.
An emulsion polymerization step in which polymerization is started in the presence of a redox catalyst consisting of an organic radical generator and a reducing agent, and a chain transfer agent is added in batches during the polymerization to continue the polymerization to obtain an emulsion polymerization solution.
A coagulation step of contacting the obtained emulsion polymerization solution with a coagulant to form a hydrous crumb,
A cleaning process to clean the generated hydrous crumbs,
The process of dehydrating the washed water-containing crumbs,
The drying process to dry the dehydrated hydrous crumb,
The veiling process to veil the dried rubber after drying,
Provided is a method for producing an acrylic rubber veil, which comprises the above-mentioned acrylic rubber veil.

In the method for producing an acrylic rubber veil of the present invention, the proportion of the hydrous crumb produced in the solidification step in the range of 710 μm to 6.7 mm is preferably 30% by weight or more.

In the method for producing an acrylic rubber veil of the present invention, it is preferable that the contact between the emulsion polymerization solution and the coagulant in the coagulation step is to add the emulsion polymerization solution to the agitated coagulation solution.

In the method for producing an acrylic rubber veil of the present invention, the stirring number of the stirred coagulant is preferably 100 rpm or more.

In the method for producing an acrylic rubber veil of the present invention, it is preferable that the peripheral speed of the agitated coagulant is 0.5 m / s or more.

In the method for producing an acrylic rubber veil of the present invention, it is preferable to carry out emulsion polymerization using a phosphoric acid ester salt or a sulfate ester salt as an emulsifier in the emulsion polymerization step, and the polymerization solution produced in the emulsion polymerization step is an alkali metal salt or It is preferable to coagulate by contacting with a coagulant containing a Group 2 metal salt in the periodic table.
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 corroded with a coagulant to coagulate, and then melt-kneaded and dried.

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 acrylic rubber, 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 veil having highly excellent injection moldability, Banbury processability, strength characteristics, compression set resistance and water resistance, an efficient manufacturing method thereof, and high quality including the acrylic rubber veil. A rubber composition and a rubber crosslinked product obtained by cross-linking the rubber composition 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 has a weight average molecular weight (Mw) to a number average molecular weight (Mn) ratio (Mw). / Mn) is made of acrylic rubber in the range of 1.5 to 3, the gel amount of methyl ethyl ketone insoluble content is 50% by weight or less, the ash content is 0.3% by weight or less, and sodium, sulfur, calcium in the ash content. , Magnesium and phosphorus are characterized in that the total amount is 80% by weight or more.

<Reactive group>
The acrylic rubber veil of the present invention is characterized by having at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom, and is involved in a crosslinking reaction to significantly improve compression resistance permanent strain resistance. There is. Among these reactive groups, it is preferably an ion-reactive group that reacts with an ion-reactive cross-linking agent.
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 such a reactive group of the present invention may be one in which a reactive group such as a carboxyl group, an epoxy group or a chlorine atom is introduced into acrylic rubber by a post-reaction, but the reactive group-containing single amount is preferable. It is an acrylic rubber veil made of acrylic rubber in which the body is copolymerized.

<Polymer component>
The monomer component 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 (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxy. At least one (meth) acrylic acid ester selected from the group consisting of alkyl esters, at least one reactive group-containing monomer selected from the group consisting of carboxyl groups, epoxy groups and chlorine atoms, and optionally. When it is made of other copolymerizable monomers, it is suitable because the properties such as short-time cross-linking property, compression set resistance, weather resistance, heat resistance, and oil resistance are highly balanced. In the present invention, "(meth) acrylic acid ester" is used as a general term for esters of acrylic acid and / or methacrylic acid.

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 veil has highly excellent weather resistance, heat resistance and oil resistance.

As the at least one reactive group-containing monomer selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom, there is no particular limitation as long as it is a functional group involved in the crosslinking reaction, and it is appropriately selected according to the purpose of use. However, when it is preferably a monomer having a carboxyl group and an epoxy group, and more preferably a monomer having a carboxyl group, the short-time crosslinkability of the acrylic rubber veil and the compression set resistance and water resistance of the crosslinked product are desired. It is suitable because it can greatly improve the sex.

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 veil 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.

These reactive group-containing monomers are used alone or in combination of two or more, and the ratio in the total components of the monomer 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% by weight.

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

These other monomers are used alone or in combination of two or more, and the 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 the above-mentioned carboxyl group, epoxy group and chlorine atom, preferably composed of the above-mentioned monomer component, and The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is within a specific range.

The monomer of the acrylic rubber constituting the acrylic rubber veil 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. It consists of a bonding unit from at least one reactive group-containing monomer selected from the group consisting of a carboxyl group, an epoxy group and a chlorine atom and other monomers contained as necessary, and each of them in the acrylic rubber. The ratio is such that the bond unit derived from at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester is usually 50 to 99.99% by weight. It is preferably in the range of 62 to 99.95% by weight, more preferably 74 to 99.9% by weight, particularly preferably 80 to 99.5% by weight, and most preferably 87 to 99% by weight, and has a carboxyl group or an epoxy group. And the bond unit derived from at least one reactive group-containing monomer selected from the group consisting of an ester atom is usually 0.01 to 10% by weight, preferably 0.05 to 8% by weight, and more preferably 0. It is in the range of 1 to 6% by weight, particularly preferably 0.5 to 5% by weight, most preferably 1 to 3% by weight, and the binding unit derived from other monomers is usually 0 to 40% by weight, preferably 0 to 40% by weight. It is in the range of 0 to 30% by weight, more preferably 0 to 20% by weight, particularly preferably 0 to 15% by weight, and most preferably 0 to 10% by weight. When the monomer composition of acrylic rubber is in this range, the properties such as short-time crosslinkability, compression set 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 usually 1 million to 5 million, preferably 1.1 million to 4 million, and more preferably 1.2 million to. Highly balanced injection moldability, molecular workability, strength properties, and compression set resistance properties of acrylic rubber veils when in the range of 3 million, particularly preferably 1.5 million to 2.5 million, most preferably 1.6 million to 2.2 million. It is suitable.

The number average molecular weight (Mn) of the acrylic rubber constituting the acrylic rubber veil of the present invention is not particularly limited, but is usually 300,000 to 1,500,000, preferably 350,000 to 1,300,000, and more preferably 400,000 to. The Banbury workability, injection moldability, strength characteristics and compression set resistance characteristics of the acrylic rubber veil are highly balanced when it is in the range of 1.1 million, particularly preferably 500,000 to 1,000,000, and most preferably 550,000 to 750,000. It is 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 according to the purpose of use, but is usually 1.5 million or more, preferably 2 million or more. It is preferably 2.5 million or more, and particularly preferably 3 million or more. The z average molecular weight (Mz) of the acrylic rubber constituting the acrylic rubber veil of the present invention is also usually 1.5 million to 6 million, preferably 1.8 million to 5.5 million, more preferably 2 million to 5 million, and particularly preferably 220. When it is in the range of 10,000 to 4.5 million, most preferably 2.5 million to 4 million, the injection moldability, molecular workability, strength characteristics, and compression set resistance characteristics 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 is 1.5 to 3, preferably 1.8 to 2.7. , More preferably in the range of 2 to 2.6, particularly preferably in the range of 2.2 to 2.6, the injection moldability of the acrylic rubber veil and the strength characteristics and compression resistance permanent strain characteristics when crosslinked are highly balanced. It is suitable. In particular, when 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 in this range, the injection moldability of the acrylic rubber veil is high. All of the properties of shape formability, fusion property and mold releasability are remarkably excellent, and the strength property as a crosslinked product and the compression resistance permanent strain property are highly balanced and suitable.

The molecular weight distribution focusing on the high molecular weight region of the acrylic rubber constituting the acrylic rubber veil of the present invention is not particularly limited, but the ratio of z average molecular weight (Mz) to weight average molecular weight (Mw) (Mz). / Mw), the weight average molecular weight is usually 1.3 or more, preferably 1.4 or more, more preferably 1.5 or more, particularly preferably 1.6 or more, and most preferably 1.7 or more. It is suitable because it can prevent deterioration of releasability and shape formability (burr generation) when (Mw) becomes excessively small. The molecular weight distribution (Mz / Mw) focusing on the high molecular weight region of the acrylic rubber constituting the acrylic rubber veil of the present invention is also usually 4 or less, preferably 3 or less, more preferably 2.5 or less, particularly preferably. When it is 2.2 or less, most preferably 2 or less, it is preferable because it can prevent deterioration of shape formability (insufficient shape) and fusion when the weight average molecular weight (Mw) becomes excessively large. be. The molecular weight distribution (Mz / Mw) focusing on the high molecular weight region of the acrylic rubber constituting the acrylic rubber veil of the present invention is further usually 1.3 to 3, preferably 1.4 to 2.5, more preferably. When it is in the range of 1.5 to 2.2, particularly preferably 1.6 to 2, and most preferably 1.7 to 1.9, injection moldability and Banbury processing are performed without impairing the strength characteristics of the acrylic rubber veil. It is suitable because the property can be highly improved.

The measurement of the molecular weight (Mn, Mw, Mz) and the molecular weight distribution (Mw / Mn, Mz / Mw) of the acrylic rubber constituting the acrylic rubber veil of the present invention is not particularly limited, but the absolute molecular weight by the GPC-MALS method. (Mn, Mw, Mz) and absolute molecular weight distribution (Mw / Mn, Mz / Mw) are suitable because each characteristic can be accurately obtained.

The measuring solvent of the GPC-MALS method for measuring the molecular weight (Mn, Mw, Mz) and the molecular weight distribution (Mw / Mn, Mz / Mw) of the acrylic rubber constituting the acrylic rubber veil of the present invention is the acrylic rubber veil of the present invention. There is no particular limitation as long as it can be dissolved and measured, but a dimethylformamide-based solvent is suitable. The dimethylformamide-based solvent used is not particularly limited as long as it contains dimethylformamide as a main component, but it can be used with 100% dimethylformamide or by adding a polar substance to dimethylformamide. The proportion of dimethylformamide in the dimethylformamide-based solvent is 90% by weight or more, preferably 95% by weight or more, and more preferably 97% by weight or more. 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. The solution 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 more excellent in oil resistance and heat resistance, and by setting it to the above upper limit or lower, the acrylic rubber bale can be processed, crosslinked and cold resistant. Can be made better.

<Acrylic rubber veil>
The acrylic rubber veil of the present invention is made of the above acrylic rubber. Moreover, the gel amount of the insoluble methyl ethyl ketone is 50% by weight or less, the ash content is 0.3% by weight or less, and the total amount of sodium, sulfur, calcium, magnesium and phosphorus in the ash content is 80% by weight or more. It is a feature.

The gel amount of the methyl ethyl ketone insoluble content 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. When the following, the processability and injection moldability at the time of kneading such as Banbury are highly improved and are suitable.

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

The acrylic rubber veil of the present invention has the Banbury workability and strength characteristics of the acrylic rubber veil when the acrylic rubber is melt-kneaded and dried in a state where almost water is removed by a screw type twin-screw extruder. Highly balanced and suitable.

The ash content of the acrylic rubber veil of the present invention is 0.3% by weight or less, preferably 0.2% by weight or less, more preferably 0.18% by weight or less, particularly preferably 0.15% by weight or less, and most preferably. When it is 0.13% by weight or less and is in this range, the fusion of water resistance, storage stability, strength characteristics, processability and injection moldability of the acrylic rubber veil is 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, 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, the workability is excellent, and the injection moldability is excellent. It is particularly suitable because it has excellent releasability.

When the acrylic rubber veil of the present invention has a high balance between water resistance, storage stability, strength characteristics, workability, workability, injection moldability, and releasability, the amount of ash is usually 0.0001 or more. 0.3% by weight, preferably 0.0005 to 0.2% by weight, more preferably 0.001 to 0.18% by weight, particularly preferably 0.005 to 0.15% by weight, most preferably 0.01. It is in the range of ~ 0.13% by weight.

When the total amount of sodium, magnesium, calcium, phosphorus and sulfur in the ash content of the acrylic rubber veil of the present invention is 80% by weight or more, preferably 90% by weight or more, more preferably 95% by weight or more, the acrylic rubber veil The water resistance and the fusion property and mold releasability of injection molding are highly improved, which is 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, injection molding fusion and releasability and processability of the acrylic rubber veil are improved. Highly balanced 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. In this case, the water resistance and strength characteristics of the acrylic rubber veil, the fusion property of injection molding, the mold releasability and the processability 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.

In order to achieve a high balance between water resistance, strength characteristics, injection molding fusion, releasability and processability of acrylic rubber veil, anionic emulsifiers and cations, which will be described later, are particularly used as emulsifiers for emulsion polymerization of acrylic rubber. It is preferable to use a sex emulsifier or a nonionic emulsifier, preferably an anionic emulsifier, more preferably a phosphate ester salt or a sulfate ester salt. 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. Water resistance, strength characteristics, fusion of injection molding, mold releasability and workability can be further balanced, which is suitable.

In order to achieve a high balance between the water resistance and strength characteristics of the acrylic rubber veil, the fusion property of injection molding, and the releasability and processability, a metal salt described later, preferably an alkali metal salt or a periodic table No. 1 is particularly used as a coagulant. It is preferable to use a group 2 metal salt. The water resistance of acrylic rubber is uniquely correlated with the amount of ash in the acrylic rubber veil and the total amount of sodium, magnesium, calcium, phosphorus and sulfur in the ash. The water resistance and strength characteristics of the bale, the fusion property of injection molding, the mold releasability and the processability are more highly balanced and 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 15,000 [Pa · s] or less. , Preferably 1,000 to 10,000 [Pa · s], more preferably 2,000 to 8,000 [Pa · s], particularly preferably 3,000 to 5,000 [Pa · s], most preferably. Is excellent in processability, oil resistance, injection moldability and shape retention when it is in the range of 3,500 to 4,000 [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, and more preferably 0.7 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 0.55 to 0.95, more preferably 0.6 to 0.9, particularly preferably 0.65 to 0.85, most preferably 0. When the range is in the range of 7 to 0.8, workability, oil resistance, and shape retention 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 0.8 or more, more preferably 0.9 or more, particularly preferably 0.95 or more, most preferably. When it is 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 the cross-linked product, 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 veil is large, and it is not preferable because it greatly affects the storage stability including oxidative deterioration.
The specific gravity of the acrylic rubber 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-method A for density measurement. It is measured according to.

Further, the acrylic rubber bale of the present invention is an acrylic rubber bale in which acrylic rubber is dried under reduced pressure by a screw type twin-screw extruder, or melted under reduced pressure and extruded and dried. It is suitable because the characteristics of the strength characteristics are particularly excellent and highly balanced.

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 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 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 manufacturing the acrylic rubber veil is not particularly limited, but for example,
At least one selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester, at least one selected from the group consisting of (meth) acrylic acid ester, carboxyl group, epoxy group and chlorine atom. In the emulsification step of emulsifying a monomer component consisting of the reactive group-containing monomer and, if necessary, other monomers with water and an emulsifier.
An emulsion polymerization step in which polymerization is started in the presence of a redox catalyst consisting of an organic radical generator and a reducing agent, and a chain transfer agent is added in batches during the polymerization to continue the polymerization to obtain an emulsion polymerization solution.
A coagulation step of contacting the obtained emulsion polymerization solution with a coagulant to form a hydrous crumb,
A cleaning process to clean the generated hydrous crumbs,
The process of dehydrating the washed water-containing crumbs,
The drying process to dry the dehydrated hydrous crumb,
The veiling process to veil the dried rubber after drying,
It can be efficiently manufactured by a manufacturing method including.

(Emulsification process)
In the emulsification step in the method for producing an acrylic rubber veil of the present invention, at least one (meth) acrylic acid ester and a carboxyl group selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester A step of emulsifying a monomer component consisting of at least one reactive group-containing monomer selected from the group consisting of an epoxy group and a chlorine atom and, if necessary, another monomer, with water and an emulsifier. Is.

(Polymer component)
The monomer component used in the present invention is at least one (meth) acrylic acid ester, a carboxyl group, or an epoxy group selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester. It is composed of at least one reactive group-containing monomer selected from the group consisting of and a chlorine atom, and other monomers that can be copolymerized as necessary, and examples of the above-mentioned monomer components. 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 constituting the acrylic rubber veil 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 injection of the obtained acrylic rubber veil are preferable. It is possible to highly balance molding fusion, mold releasability and processability. 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 phosphoric acid ester, tridecyloxyoctaoxyethylene phosphoric acid ester, tetradecyloxyoctaoxypropylene phosphoric acid ester, hexadecyloxyoctaoxypropylene phosphoric acid ester, octadecyloxyoctaoxypropylene phosphoric acid ester 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.

(Emulsion polymerization process)
In the emulsion polymerization step in the method for producing an acrylic rubber veil of the present invention, polymerization is started in the presence of a redox catalyst composed of a radical generator and a reducing agent, and a chain transfer agent is sequentially post-added during the polymerization to carry out the polymerization. This is a step of continuously obtaining an emulsion polymerization solution.

(Radical generator)
The polymerization catalyst used in the present invention is characterized by using a redox catalyst composed of an organic radical generator and a reducing agent. In particular, it is suitable because the injection moldability of the acrylic rubber veil produced by using an organic radical generator can be highly improved.

The organic radical generator is not particularly limited as long as it is usually used in emulsion polymerization, and examples thereof include organic peroxides and azo compounds.

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

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

These organic radical generators can be used alone or in combination of two or more, and the amount used is usually 0.0001 to 5 parts by weight, preferably 0.0001 to 5 parts by weight, based on 100 parts by weight of the monomer component. Is in the range of 0.0005 to 1 part by weight, more preferably 0.001 to 0.5 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. The acrylic rubber veil, which can be combined with other reducing agents, is suitable because it has a higher balance between the Banbury processability, the injection moldability, and the strength characteristics.

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. It is in the range of ~ 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 and injection moldability of the manufactured acrylic rubber veil 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 injection moldability 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. Banbury workability, strength characteristics and injection moldability are highly balanced and suitable.

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, and high molecular weight components and low molecular weight components of the acrylic rubber to be produced are produced and the molecular weight distribution is distributed. It is suitable because it can highly balance the molecular workability, strength characteristics, and injection moldability of the acrylic rubber veil 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. It is particularly preferable that the acrylic rubber veil produced when the number of times is twice can be highly balanced between the Banbury workability, the strength characteristics and the injection moldability.

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 Banbury processability, strength characteristics and injection of the acrylic rubber veil produced more preferably in the range of 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. It is suitable because the moldability can be highly balanced.

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 it can highly balance the Banbury workability, strength characteristics, and injection moldability of the acrylic rubber veil manufactured when the weight is in the range of ~ 0.02 parts by weight.

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 and the injection moldability of the acrylic rubber veil produced by doing so can be highly balanced, which is preferable. be.

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 it is in the range of 05 parts by weight, the productivity of acrylic rubber production is excellent, and the strength characteristics and injection moldability of the produced acrylic rubber veil 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 after the initial stage of polymerization 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 production is excellent, and the strength characteristics and injection moldability of the produced acrylic rubber veil 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 it is in the range of 5 to 2.5 hours, the productivity of acrylic rubber production is excellent, and the strength characteristics and injection moldability of the produced acrylic rubber veil 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. Acrylic produced in the range of 0.5 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 rubber veil and the injection moldability.

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 90% by weight or more, preferably 95% by weight or more, and the acrylic rubber veil produced at this time is suitable because it has excellent strength characteristics and no monomeric odor. A polymerization inhibitor may be used to terminate the polymerization.

(Coagulation process)
The coagulation step in the method for producing an acrylic rubber veil of the present invention is a step of contacting the obtained emulsion polymerization solution with a coagulant to form a hydrous crumb.

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 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, fusion property of injection molding, releasability and processability of the acrylic rubber veil obtained when the salt is 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 preferable because the acrylic rubber veil can be sufficiently coagulated, and the compression-resistant permanent strain resistance and water resistance when the acrylic rubber is crosslinked can be highly improved.

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 agitated (coagulation). It can be carried out by adding it to the agent aqueous solution), or by setting the coagulant concentration of the coagulant, the number of agitated coagulants and the peripheral speed within a specific range.

The coagulant used is usually used as an aqueous solution, and the coagulant concentration in the aqueous solution is usually 0.1 to 20% by weight, preferably 0.5 to 15% by weight, more preferably 1 to 10% by weight. Particularly preferably, the particle size of the hydrous crumb generated when the range is in the range of 1.5 to 5 can be uniformly focused in a specific region, which is preferable.

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.

As a method of contacting the emulsified heavy liquid and the coagulating liquid, a method of adding the emulsion polymerization liquid to the agitated coagulating liquid is selected, and the acrylic rubber which can obtain remarkably excellent cleaning efficiency and dehydration efficiency of the produced hydrous crumb. It is suitable because it can greatly improve the water resistance and storage stability of the veil.

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 such that the water-containing crumb particle size is small and uniform, and the crumb particle size is excessively large and small by setting the rotation speed to be equal to or higher than the above lower limit. It is possible to suppress the formation of a substance, and by setting it to the upper limit or less, it is possible to more easily control the solidification 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 (contact 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 a step of cleaning the water-containing crumb produced above.

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

The amount of 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 water used is not particularly limited, but it is preferable to use hot water, usually 40 ° C. or higher, preferably 40 to 100 ° C., more preferably 50 to 90 ° C., and particularly when 60 to 80 ° C. It is optimal because it can significantly improve the cleaning efficiency. 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 washed water-containing crumb can be provided with a dehydration step of dehydrating if necessary before the drying step.

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 veil 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 water-containing crumb that has been dehydrated after washing as needed.

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 Banbury workability, injection moldability 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, the water-containing crumb is melt-kneaded and dried under reduced pressure in a screw-type twin-screw extruder, and the storage stability is improved without impairing the strength characteristics and injection moldability of the acrylic rubber veil. It is suitable because it is enhanced to. 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, the water-containing crumb is melt-kneaded and dried with almost no water removed by a screw-type twin-screw extruder, without impairing the strength characteristics and injection moldability of the acrylic rubber veil. 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 the range is within m, the Banbury workability, injection moldability and strength characteristics of the manufactured 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 vanbury workability, injection moldability 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 vanbury workability, injection moldability 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, injection moldability, Banbury processability 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, injection moldability, 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.

In the present invention, the cooling rate after melt kneading and drying 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. Particularly preferably, the scorch stability when the acrylic rubber veil is used as a rubber composition when rapidly cooled to 150 ° C./hr or more is significantly improved, which is preferable.

(Veiling process)
The veiling step in the method for producing an acrylic rubber veil 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 using sheet-shaped dry rubber)
In the method for producing an acrylic rubber veil of the present invention,
After dehydrating the water-containing crumb after washing to a water content of 1 to 40% by weight in a dehydration barrel using a dehydration barrel having a dehydration slit, a drying barrel under reduced pressure, and a screw-type twin-screw extruder having a die at the tip. Dehydration / drying / molding process that dries to less than 1% by weight in a drying barrel and extrudes sheet-shaped dry rubber from the die.
A laminating process of laminating and veiling extruded sheet-shaped dry rubber,
The banbury workability, injection moldability and storage stability of the acrylic rubber veil obtained by the above can be remarkably improved, which is suitable.

(Draining process)
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.

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 / drying: molding process)
In the dehydration / drying / molding process, the water-containing crumb that has been washed and drained as needed is used in a dehydration barrel with a dehydration slit, a drying barrel under reduced pressure, and a screw-type twin-screw extruder with a die at the tip. This is the process of dehydrating to a water content of 1 to 40% by weight in a dehydration barrel, then drying to less than 1% by weight in a drying barrel, and extruding the sheet-shaped dry rubber from the die.

(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, ash content, water content, operating conditions, etc. of the acrylic rubber, 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 ° C. 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 35% by weight, and more preferably 10 to 35% by weight. Sometimes productivity and ash removal efficiency are well balanced and suitable.

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, the water content can be reduced to this extent by using a screw type twin-screw extruder having a dehydration slit and forcibly squeezed with a screw.

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)
Drying of the hydrous crumb after dehydration is characterized in that it is performed 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 of the acrylic rubber veil 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 veil. It is suitable because it can significantly improve the storage stability of acrylic rubber.

The set temperature of the drying barrel may be appropriately selected, but when it is usually in the range of 100 to 250 ° C., preferably 110 to 200 ° C., more preferably 120 to 180 ° C., there is no discoloration or deterioration of the acrylic rubber. It is suitable because it can be dried efficiently and the amount of gel of the insoluble matter of methyl ethyl ketone 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 to raise the temperature of (1) because the drying efficiency can be improved.

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 methyl ethyl ketone insoluble in sheet-shaped or veil-shaped acrylic rubber is melt-extruded with the water content of the dried rubber set to this value (with almost all water removed), especially in a screw-type twin-screw extruder. It is suitable because the amount of gel can be reduced. 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 5 [1 / s]. As described above, the storage stability, injection moldability, Banbury processability, and strength characteristics of the acrylic rubber veil obtained preferably in the range of 10 to 400 [1 / s], more preferably 20 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, injection moldability, 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 portions 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 extruder and operating conditions)
The screw length (L) 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 3000 to 15000 mm, preferably 4000 to 10000 mm, and more preferably 4500 to 8000 mm. Is.

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 used may be appropriately selected according to various conditions, but is usually 10 to 1000 rpm, preferably 50 to 750 rpm, more preferably 100 to 500 rpm, and most preferably. It is preferable that the water content of the acrylic rubber veil and the gel amount of the insoluble 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 1500 kg / hr, preferably 300 to 1200 kg / hr, more preferably 400 to 1000 kg / hr, and most preferably. It is in the range of 500 to 800 kg / hr.

The ratio (Q / N) of the extrusion amount (Q) to the rotation speed (N) of the screw type 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 5 to 125 Nm, preferably 10 to 100 Nm, more preferably 10 to 50 Nm, and particularly preferably. Is suitable because it can highly balance the injection moldability, Banbury processability and strength characteristics of the produced acrylic rubber veil when it is in the range of 15 to 45 Nm.

The specific power of the screw type twin-screw extruder used is not particularly limited, but is usually 0.01 to 0.3 [kW · h / kg] or more, preferably 0.05 to 0.2 [kW]. -H / kg], more preferably in the range of 0.1 to 0.2 [kW-h / kg], the injection moldability, Banbury processability and strength characteristics of the acrylic rubber veil obtained are highly balanced. Suitable.

The specific power of the screw type twin-screw extruder used is not particularly limited, but is usually 0.1 to 0.6 [A · h / kg] or more, preferably 0.15 to 0.55 [A]. · H / kg], more preferably in the range of 0.2 to 0.5 [A · h / kg], the injection moldability, 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 5 to 150 [1 / s] or more, preferably 10 to 100 [1 / s], and more preferably 25 to 75. The storage stability, injection moldability, Banbury processability 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, injection moldability, Banbury processability 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 dry 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 4500 [Pa · s], and most preferably 3000 to 4000 [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 2,500 to 7,000 [Pa · s], most preferably 2,700 to 5,500 [Pa · s] without entraining air and continuously cutting. Is suitable.

The ratio ([η] 100 ° C / [η] 60 ° C) between the complex viscosity ([η] 100 ° C) at 100 ° C and the complex viscosity ([η] 60 ° C) at 60 ° C of the sheet-shaped dried rubber 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, and the complex viscosity of the sheet-shaped dried rubber at 100 ° C. The ratio ([η] 100 ° C./[η] 60 ° C.) of ([η] 100 ° C.) to the complex viscosity ([η] 60 ° C.) at 60 ° C. is also usually 0.5 to 0.99. It is preferably in the range of 0.55 to 0.95, more preferably 0.6 to 0.9, particularly preferably 0.65 to 0.85, and most preferably 0.7 to 0.8. 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 cut when it is 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. Is easy and suitable. 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 acrylic rubber composition is excellent in scorch stability 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.

(Laminating process)
The laminating step is a step of laminating the above-mentioned sheet-shaped dry rubber to obtain an acrylic rubber veil having excellent storage stability with less air entrainment.

The laminating temperature of the sheet-shaped dry rubber is not particularly limited, but is suitable because air entrained during laminating can be released when it is usually 30 ° C. or higher, preferably 35 ° C. or higher, and more preferably 40 ° C. or higher. 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.

The acrylic rubber veil of the present invention thus obtained is superior in operability as compared with crumb-shaped acrylic rubber, and is also excellent in Banbury workability, cross-linking property, strength property, compression permanent strain resistance and water resistance, as well as storage stability and injection. It has excellent moldability 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 rubber composition vanbury is preferably a reinforcing filler. It is suitable because it is excellent in processability, injection moldability and cross-linking property in a short time, 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 Banbury processability, injection moldability and short-time cross-linking property, and the water resistance and strength of the cross-linked product are excellent. It is particularly suitable because it has 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, based on 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 an acrylic rubber veil according to an embodiment of the present invention will be described. FIG. 1 is a diagram schematically showing an example of an acrylic rubber manufacturing system having an apparatus configuration used for manufacturing an acrylic rubber veil according to an embodiment of the present invention. For the production of the acrylic rubber veil 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 organic 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 process 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 liquid 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 an optimum 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 as long as it is a shape required for each

barrel portion

52, 53, 54, and is not particularly limited.

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

The dehydration barrel portion 53 is a region for separating and discharging a liquid (serum water) containing a coagulant or the like from the 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 ° C. to 120 ° C., preferably 70 to 110 ° C., more preferably 80 to 100 ° C., and the set temperature of the dehydration barrel to be dehydrated in the exhausted steam state is usually 100 to 150 ° C. It 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 5 to 125 Nm, preferably 10 to 100 Nm, more preferably 10 to 50 Nm, and particularly preferably 15 to 45 Nm. Is the range of.

The specific power in the barrel unit 51 is not particularly limited, but is usually 0.01 to 0.3 [kW · h / kg] or more, preferably 0.05 to 0.25 [kW · h / kg]. More preferably, it is in the range of 0.1 to 0.2 [kW · h / kg].

The specific power in the barrel unit 51 is not particularly limited, but is usually 0.1 to 0.6 [A ・ h / kg] or more, preferably 0.15 to 0.55 [A ・ h / kg]. More preferably, it is in the range of 0.2 to 0.5 [A.h / kg].

The shear rate in the barrel unit 51 is not particularly limited, but is usually 5 to 150 [1 / s] or more, preferably 10 to 100 [1 / s], and more preferably 25 to 75 [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 bale-shaped acrylic rubber 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-forming device 7 may be provided with, for example, a bale, and the bale-shaped acrylic rubber may be manufactured by compressing the cooled dried rubber with the bale.

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

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

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

[Polymer 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 the 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 sample (acrylic rubber veil) 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]
For the amount (%) of each component in the acrylic rubber veil ash content, the ash content collected during the above ash content measurement was pressure-bonded to a Φ20 mm drip filter paper, and the component amount (ppm) was determined using ZSX Primus (manufactured by Rigaku). It was measured by XRF and calculated as the ratio in the above ash content.

[Molecular weight and molecular weight distribution]
The molecular weight (Mw, Mn, Mz) and molecular weight distribution (Mw / Mn and Mz / Mw) of acrylic rubber are such that lithium chloride is 0.05 mol / L and 37% concentrated hydrochloric acid is 0.01% in dimethylformamide as a solvent. It is an absolute molecular weight and an absolute molecular weight distribution measured by the GPC-MALS method using the solutions added in 1. Here, the "GPC-MALS method" has the following contents. The GPC (gel permeation chromatography) method is a type of liquid chromatography that separates based on the difference in molecular size. Incorporating a differential refractive index meter (RI), the molecular weight of the solute and its content are sequentially calculated by measuring the light scattering intensity and refractive index difference of the molecular chain solution size-separated by a GPC device in accordance with the melting time. Finally, it is a method for obtaining the absolute molecular weight distribution and the absolute average molecular weight value of the polymer substance.

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).

In this way, the molecular weight of the solute and its content were sequentially calculated and obtained. The measurement conditions and measurement method by the GPC 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 rubber sample, 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.).

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

[specific gravity]
The specific gravity of the acrylic rubber veil was measured according to the method A of JIS K6268 crosslinked rubber-density measurement.
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 acrylic rubber in 100 g of tetrahydrofuran, adding 2.0 ml of distilled water to confirm that it was completely dissolved, and then confirming that it was completely dissolved.

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

[Injection moldability]
The injection moldability was evaluated by observing and scoring shape formability, mold releasability, and fusion property using a small injection molding machine (SLIM15-30: manufactured by Daihan Co., Ltd.), and comprehensively evaluating the total score according to the following criteria. For shape formability and mold releasability, prepare a mold in the shape of three cylindrical shapes (A: 4 mmφ, B: 3 mmφ, C: 2 mmφ) with different diameters with a shaft length of more than 150 mm, and screw temperature to this mold. The rubber composition was flowed in under the conditions of 90 ° C., injection time of 30 seconds, and injection pressure of 7 MPa, and after cross-linking at a mold temperature of 170 ° C. for 1 minute and 30 seconds, the injection-molded cylindrical molded product was taken out, and the cylindrical molded product was taken out. And the mold was observed and scored according to the following criteria. For fusion, prepare a mold in the shape of a fusion observation band with a thickness of 0.5 mm, a width of 5 mm, and a length of 40 mm, in which 5 mmφ pipes are connected to each of both ends in the length direction. The rubber composition was flowed into the fusion observation zone from each of the above under the conditions of a screw temperature of 90 ° C., an injection time of 30 seconds, and an injection pressure of 7 MPa, and the rubber composition in the fusion observation body was crosslinked at a mold temperature of 170 ° C. for 1 minute and 30 seconds. We observed the fusion condition of the above and scored according to the following criteria.

(Shape formability)
5 points: A cylindrical molded product can be manufactured in all of A, B, and C, and the shape of the tip of the molded product is completely followed by the mold in all cases, and no burr formation is observed. 4 points: A, A cylindrical molded product can be manufactured in all of B and C, but in C, only a part of the tip of the molded product cannot completely follow the mold shape. 3 points: Cylindrical molding in A and B The product can be manufactured, and more than half of the molded product can be manufactured in C. 2 points: The cylindrical molded product can be manufactured in A and B, but the molded product cannot be manufactured in half in C. 1 point: Molded product can be manufactured in A, but molded product cannot be completely manufactured in B. 0 point: Molded product cannot be manufactured in A.

(Releasability)
5 points: Easy to release from the mold and no mold residue 4 points: Easy to release from the mold but only a small amount of mold residue is recognized 3 points: Easy to release from the mold but there is no mold residue Slightly present 2 points: Slightly difficult to remove from the mold but no mold residue 1 point: Slightly difficult to remove from the mold and some mold residue 0 point: Difficult to remove from the mold

(Fusionability)
5 points: Fusion is complete 0 points: Fusion is incomplete (fusion failure)

Comprehensive evaluation ◎: Perfect score (15 points)
〇: 14 points □: 13 points △: 11-12 points ×: 10 points or less

[Banbury workability]
For the rubbery processability of the rubber sample, the rubber sample is put into a Banbury mixer heated to 50 ° C., kneaded for 1 minute, and then the compounding agent A containing the rubber mixture shown in Table 1 is added to the rubber mixture in the first stage. The time until the rubber was integrated to show the maximum torque value, that is, BIT (Black Incorporation Time) was measured, and an index with Comparative Example 2 as 100 was calculated and evaluated according to the following criteria.
◎: 20 or less 〇: 20 or more and 40 or less □: 40 or more and 60 or less △: 60 or more and 80 or less ×: 80 or more

[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. An index with 2 as 100 was calculated and evaluated according to the following criteria.
◎: 20 or less 〇: 20 or more and 50 or less □: 50 or more and 90 or less △: 90 or more and 100 or less ×: 100 or more

[Water resistance evaluation]
The water resistance of the rubber sample is determined by immersing the crosslinked product of the rubber sample in distilled water at a temperature of 85 ° C. for 100 hours in accordance with JIS K6258, performing a dipping test, measuring the volume change rate before and after dipping, and referencing Comparative Example 2. An index of 100 was calculated and evaluated according to the following criteria.
◎: 1 or less 〇: 1 or more and 5 or less □: 5 or more and 10 or less △: 10 or more and 50 or less ×: 50 or more

[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 gel amount]
The variation in the gel amount of the rubber sample is evaluated by measuring the gel amount of 20 points arbitrarily selected from 20 parts (20 kg) of the rubber sample and evaluating based on the following criteria.
⊚: Calculate the average value of the measured 20-point gel amount, and include all the measured 20 points within the range of the average value ± 3. 〇: Calculate the average value of the measured 20-point gel amount. 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 is out of the range, but within the range of the average value ± 5 20 (Those that contain all the points)
×: The average value of the gel amount of the measured 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 storage 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, 48.5 parts of ethyl acrylate as a monomer component, 50 parts of n-butyl acrylate and mono n-butyl fumarate. A monomer emulsion was obtained by adding 1.5 parts and 1.8 parts of tridecyloxyhexaoxyethylene phosphate sodium salt as an emulsifier and stirring.

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 parts of sodium ascorbate, and 0.0045 parts of diisopropylbenzene hydroperoxide, which is an organic 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. .012 parts and 0.4 part of sodium L-ascorbate were added after 120 minutes 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 emulsified 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 solidified acrylic rubber crumb. And 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. Table 2-1 shows the water content, maximum torque, specific power, specific power, shear rate and shear viscosity after dehydration (drainage) of the screw type twin-screw extruder.

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: 40N ・ 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, gel amount, pH, specific gravity, glass transition temperature (Tg), water content, molecular weight, molecular weight distribution, and 100 ° C. and 60 of the obtained acrylic rubber veil (A). The complex viscosity at ° 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). At this time, the BIT was measured to evaluate the Banbury workability, 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" shown in Table 1 was mixed and mixed (second-stage mixing) to obtain a rubber composition. The injection moldability of the obtained rubber composition was evaluated, and the results are shown in Table 2-2.

Next, the residual 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 obtain a primary crosslink. The primary crosslinked product was further heated in a gear oven at 180 ° C. for 2 hours for secondary cross-linking to obtain a sheet-shaped rubber crosslinked product. Then, a 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. The results are shown in Table 2-2.

[Example 2]
As shown in Table 2-1, the same as in Example 1 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. To obtain acrylic rubber veil (B), each characteristic (combination agent is "formulation 2" (see Table 1)).
Changed to) was evaluated. The results are shown in Table 2-2.

[Example 3]
The post-addition of n-dodecyl mercaptan was carried out in the same manner as in Example 1 except that the post-addition was changed to 0.008 part after 50 minutes, 0.008 part after 100 minutes and 0.008 part after 120 minutes, for a total of three times. A rubber veil (C) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

[Example 4]
The post-addition of n-dodecyl mercaptan was carried out in the same manner as in Example 2 except that the post-addition was changed to 0.008 part after 50 minutes, 0.008 part after 100 minutes and 0.008 part after 120 minutes, for a total of three times. A rubber veil (D) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

[Example 5]
As shown in Table 2-1 the same procedure as in Example 1 was carried out except that the maximum torque of the screw type twin-screw extruder was changed to 15 Nm, and acrylic rubber veil (E) was obtained and each characteristic was evaluated. .. The results are shown in Table 2-2.

[Example 6]
The same procedure as in Example 2 was performed except that the maximum torque of the screw type twin-screw extruder was changed to 15 N · m, and acrylic rubber veil (F) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

[Example 7]
The same procedure as in Example 5 was carried out except that the water content after dehydration in the dehydration barrel portion of the screw type twin-screw extruder was set to 30% by weight, and acrylic rubber veil (G) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

[Example 8]
The same procedure as in Example 6 was carried out except that the water content after dehydration in the dehydration barrel portion of the screw type twin-screw extruder was set to 30% by weight, and acrylic rubber veil (H) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

[Example 9]
The water-containing crumb after washing is dried to a water content of 0.4% using a hot air dryer at 160 ° C. to obtain a crumb-shaped acrylic rubber (I), which is then filled in a 300 × 650 × 300 mm baler and charged at 3 MPa. Acrylic rubber bale (I) 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 bale-shaped acrylic rubber. Each property of the acrylic rubber veil was evaluated, and the results are shown in Table 2-2.

[Example 10]
Acrylic rubber was carried out in the same manner as in Example 9 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 (J) was obtained and each characteristic (the compounding agent was changed to "formulation 3" (see Table 1)) was evaluated. The results are shown in Table 2-2.

[Example 11]
Example 9 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 (K) was obtained and each characteristic (the compounding agent was changed to "formulation 4" (see Table 1)) was evaluated. The results are shown in Table 2-2.

[Example 12]
The post-addition of n-dodecyl mercaptan was carried out in the same manner as in Example 11 except that the post-addition was changed to 0.008 part after 50 minutes, 0.008 part after 100 minutes and 0.008 part after 120 minutes, for a total of three times. A rubber veil (L) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

[Example 13]
Diisopropylbenzene hydroperoxide was changed to 0.0048 parts, and 0.024 parts of n-dodecyl mercaptan was continuously added to the monomer emulsion and not added afterwards. Veil (M) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

[Comparative Example 1]
The solidification reaction was carried out by adding a 0.7% magnesium sulfate aqueous solution to the stirring emulsion polymer solution (stirring number 100 rpm, peripheral speed 0.5 m / s) after the emulsion polymerization, and the emulsion was not veiled by a baler. In the same manner as in Example 13 except that a crumb-shaped acrylic rubber was obtained, each characteristic was evaluated by obtaining a crumb-shaped acrylic rubber (N). The results are shown in Table 2-2.

[Comparative Example 2]
The diisopropylbenzene hydroperoxide was changed to 0.005 part, and the same procedure as in Comparative Example 1 was carried out except that the chain transfer agent was not added. A crumb-shaped acrylic rubber (O) was obtained and each characteristic was evaluated. The results are shown in Table 2-2.

From Table 2-2, the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) having at least one reactive group selected from the group consisting of the carboxyl group, the epoxy group and the chlorine atom of the present invention (Mw). Mw / Mn) is made of acrylic rubber in the range of 1.5 to 3, the gel amount of methyl ethyl ketone insoluble content is 50% by weight or less, the ash content is 0.3% by weight or less, and sodium and sulfur in the ash content. Acrylic rubber veil (A) to (M) having a total amount of calcium, magnesium and phosphorus of 80% by weight or more have normal physical properties including injection moldability, Banbury processability, water resistance, compression resistance permanent strain property and strength property. It can be seen that the above is excellent and the storage stability is also excellent (Examples 1 to 13).

From Table 2-2, the acrylic rubber veil (A) to (M) and the crumb-shaped acrylic rubber (N) to (O) of Examples and Comparative Examples of the present application have ionic reactivity of a carboxyl group, an epoxy group, or a chlorine atom. It can be seen that having a group is excellent in normal physical properties including compression resistance permanent strain resistance and strength characteristics (Examples 1 to 13 and Comparative Examples 1 to 2). However, the crumb-shaped acrylic rubbers (N) to (O) are inferior in injection moldability, Banbury processability, water resistance and storage stability (Comparative Examples 1 and 2).

From Table 2-2, the injection moldability is strongly influenced by the molecular weight distribution (Mw / Mn) of the acrylic rubber. Comparative Example 2 is Mw / Mn = 1.3 / injection moldability: ×, and Example 13 is Mw. / Mn = 1.55 / Injection moldability: Δ, Example 12 is Mw / Mn = 1.99 / Injection moldability: 〇, Examples 3 to 11 are Mw / Mn 2.39 to 2.45 / Injection moldability : ◎), and the acrylic rubber veil of the present invention when Mw / Mn is around 2.4 as Mw / Mn = 2.91 to 2.94 / injection moldability: 〇 in Examples 1 and 2. It can be seen that the injection moldability of is the best. Further, the molecular weight distribution (Mz / Mw) focusing on the high molecular weight region is sufficiently wide, the number average molecular weight (Mn), the weight average molecular weight (Mw) and the z average molecular weight (Mz) are sufficiently large, and the Mw of the present invention is obtained. It can be seen that the injection moldability can be improved in the range of / Mn without impairing the strength characteristics (comparison between Examples 1 to 13 and Comparative Example 2).

From Tables 2-1 and 2-2, acrylic rubber veils (A) to (M) having a specific range of molecular weight distribution (Mw / Mn) having excellent injection moldability without impairing strength characteristics generate a specific amount of organic radicals. It can be seen that it can be produced by using an agent and a chain transfer agent, particularly n-dodecyl mercaptan as a chain transfer agent (Examples 1 to 13). From Tables 2-1 and 2-2, the chain transfer agent (n-dodecyl mercaptan) is added earlier than the chain transfer agent (n-dodecyl mercaptan) is continuously added (Example 13). It can be seen that the injection moldability can be improved without impairing the strength characteristics by adding the dodecyl batch in batches (Examples 1 to 12). This is because one polymerized chain is extended by reducing the amount of the organic radical generator without adding the chain transfer agent at the initial stage, and by adding the chain transfer agent during the polymerization, it becomes clear in the GPC chart. It is presumed that the high molecular weight component and the low molecular weight component can be produced in a well-balanced manner and the molecular weight distribution (Mw / Mn) can be set in a specific range, and the strength characteristics and the injection moldability are highly balanced. Further, in order to efficiently widen the molecular weight distribution (Mw / Mn), the number of batch post-additions has a great influence, and the number of batch post-additions is 2 times rather than 3 times. Mw / Mn) is wide (comparison between Examples 9 to 11 and Example 12). Although not shown in Tables 2-1 and 2-2, in the examples of the present application, the reducing agent sodium ascorbate was added 120 minutes after the start of the polymerization, whereby the high molecular weight component of the acrylic rubber was added. The formation is facilitated and the effect of widening the molecular weight distribution (Mw / Mn) of the addition after the chain transfer agent is increased.

From Tables 2-1 and 2-2, and if the drying of the hydrous crumb is changed from direct drying to a screw type twin-screw extruder and the operation is performed under normal conditions, the molecular weight distribution (Mw / Mn) does not change (Mw / Mn). Comparison between Examples 5 to 8 and Examples 9 to 11), the molecular weight distribution (Mw / Mn) of the acrylic rubber is expanded by setting the drying conditions of the screw type twin-screw extruder with the optimum share, and the acrylic rubber veil Although the injection moldability can be further improved (comparison between Examples 3 to 4 and Example 12), it can be seen that if the molecular weight distribution (Mw / Mn) is too wide, the effect of the injection moldability is reduced (Examples 1 to 12). Comparison between 2 and Examples 5 to 8). Further, although not shown in the comparative example of the present application, it can be seen that the molecular weight distribution (Mw / Mn) of the acrylic rubber obtained by using the redox catalyst of the inorganic radical generator is too wide and the injection moldability is inferior. In the case of an organic radical generator, the polymerization catalyst is inside the emulsion polymerization micelle and the polymerization is continuously carried out inside the micelle, but in the case of an inorganic radical generator, the polymerization catalyst exists outside the micelle and polymerizes outside the micelle. It is considered that these differences in molecular weight distribution occurred due to the above-mentioned factors, which affected the injection moldability.

From Tables 2-1 and 2-2, it can be seen that the Banbury processability correlates with the amount of gel of the insoluble methyl ethyl ketone (comparison between Examples 1 to 13 and Comparative Examples 1 and 2). The gel amount of the methyl ethyl ketone insoluble component of acrylic rubber can be reduced by emulsion polymerization in the presence of a chain transfer agent (comparison between Examples 9 to 13 and Comparative Example 1 and Comparative Example 2), and in particular, methyl ethyl ketone. Since the amount of insoluble gel is rapidly increased when the polymerization conversion rate is increased in order to enhance the strength characteristics, the amount of methyl ethyl ketone insoluble in Examples 9 to 13 of the post-addition of the chain transfer agent in the latter half of the polymerization reaction. It can be seen that gel formation can be suppressed. The gel amount of the acrylic rubber bale is further significantly reduced by drying the hydrous crumb with a screw type twin-screw extruder, and the Banbury workability of the manufactured acrylic rubber bale is significantly improved (Example). Comparison between 1 to 8 and Examples 9 to 13). In the present invention, although not shown in this example, the amount of gel of the methyl ethyl ketone insoluble content that rapidly increased by emulsion polymerization without adding a chain transfer agent (Comparative Examples 1 and 2) is in the screw type twin-screw extruder. It has been confirmed that it disappears when it is melt-kneaded in a state where it does not contain substantially water (water content is less than 1% by weight), and the Banbury processability can be significantly improved.

From Table 2-2, regarding the water resistance, the acrylic rubber veils (A) to (M) of the present invention are excellent (comparison between Examples 1 to 13 and Comparative Examples 1 and 2), and among them, among them. Acrylic rubber veil (A)-(F)> Acrylic rubber veil (G)-(H)> Acrylic rubber (Veil I)-(J)> Acrylic rubber veil (K)-(M), especially acrylic rubber It can be seen that the veils (A) to (F) are remarkably excellent (comparison in Examples 1 to 13), and that they are greatly affected by the amount of ash in the acrylic rubber (Example 1). Comparison in ~ 13 and Comparative Examples 1 and 2).

From Tables 2-1 and 2-2, the amount of ash in the acrylic rubber veil increases the coagulation liquid concentration (2%) in the coagulation reaction, and the emulsion polymerization solution is added to the agitated coagulation liquid. It can be seen that the weight can be significantly reduced by changing to (Lx ↓) and vigorously stirring the coagulant (stirring number 600 rpm / peripheral speed 3.1 m / s) (comparison between Examples 9 to 13 and Comparative Example 1). .. This is because the emulsion reaction is carried out by adding the emulsion polymerization solution in the coagulation liquid which is particularly vigorously stirred, and the data will be described later. The crumb diameter of the hydrous crumb generated by the coagulation reaction is 710 μm or more. It is focused in a small particle size range of 4.75 mm, which greatly improves the cleaning efficiency with warm water and the removal efficiency of emulsifiers and coagulants during dehydration, reduces the amount of ash in the acrylic rubber veil, and is water resistant. It is presumed that it has improved significantly. Further, regarding water resistance, in Examples 9 to 13, the acrylic rubber veils (I) to (J) are superior to the acrylic rubber veils (K) to (M), although the ash content is about the same. I understand. It can be seen that among the ionic reactive groups, the acrylic rubber veil having a carboxyl group or an epoxy group is superior to the chlorine atom in terms of water resistance (Examples 9 to 10 and Examples 11 to 13). comparison).

From Tables 2-1 and 2-2, and with regard to water resistance, by dehydrating the water-containing crumb before drying (squeezing out the water), the amount of ash in the acrylic rubber veil is further significantly reduced and the water resistance is significantly improved. (Comparison between Examples 1 to 8 and Examples 9 to 13), and the ash content is better when the water content after dehydration is 20% rather than 30% and more water is squeezed out from the water content crumb. It can be seen that the water resistance of the acrylic rubber veil can be significantly improved by reducing the amount of water (comparison between Examples 1 to 6 and Examples 7 to 8).

From Tables 2-1 and 2-2, the ash components of the acrylic rubber veil (A) to (M) of the present invention and the crumb-shaped acrylic rubber (N) to (O) of the comparative example are phosphorus (P). If the total amount of magnesium (Mg), sodium (Na), calcium (Ca) and sulfur (S) is 80% by weight or more or 90% by weight or more and the ash content can be reduced, it can be seen that the water resistance can be improved. Further, when the ash component is these components, the releasability of acrylic rubber is remarkably excellent. From Table 2-2, the ash content of the acrylic rubber veil (A) to (M) of the present invention solidified, washed and dehydrated by the method of the present invention is 80% or more with phosphorus (P) and magnesium (Mg). Or it can be seen that it is 90% or more (Examples 1 to 13 and Comparative Examples 1 to 2). This is because the ash in the acrylic rubber veil does not retain the emulsifier and coagulant used in the production as it is, but the phosphate ester Na salt of the emulsifier exchanges salt with the coagulant magnesium sulfate (00544) during the coagulation reaction. It is contained in the hydrous crumb as a water-resistant phosphate ester Mg salt and cannot be sufficiently removed in the cleaning process, but it can be reduced by dehydrating it in a screw-type twin-screw extruder (squeezing out water from the hydrous crumb) (implemented). Examples 1 to 8) show that the water content of the acrylic rubber veil can be significantly improved by squeezing out 20% of the water content after dehydration from the water-containing crumb to reduce the ash content (). Comparison between Examples 1 to 6 and Examples 7 to 8).

Regarding water resistance, data was omitted in the examples of the present application, but when a phosphate ester salt is used as an emulsifier, it cannot be easily reduced in the cleaning process, and in particular, it can hardly be reduced in cleaning at room temperature no matter how many times the cleaning is performed. It can be improved by washing with warm water, while it has better water resistance than ash containing a large amount of sulfur (S) and sodium (Na) using a sulfate ester salt such as sodium lauryl sulfate as an emulsifier, and in particular, the same amount of ash. If so, it was excellent in water resistance more than 5 times. Further, even when a sulfate ester salt such as sodium lauryl sulfate is used as an emulsifier, the ash content can be reduced to 0.1% by weight or less by performing the coagulation reaction of the present invention, washing with warm water and dehydrating, and the water resistance is remarkably improved. We have confirmed that it can be improved.

From Table 2-2, the acrylic rubber veil (A) to (M) of the present invention are excellent in normal physical properties including injection moldability, Banbury workability, water resistance, compression set resistance and strength property, and storage stability. It turns out that is much better.

From Table 2-2, regarding the storage stability, the specific densities of the acrylic rubber veils (A) to (M) are much larger than those of the crumb-shaped acrylic rubbers (N) to (O). It can be seen that the storage stability depends on the amount of entrainment (comparison with Examples 1 to 8, Examples 9 to 13 and Comparative Examples 1 to 2). Acrylic rubber veils with a large specific density are laminated by compressing crumb-shaped acrylic rubber with a baler to form a veil (Examples 9 to 13), and more preferably extruding into a sheet shape with a screw-type twin-screw extruder. It can be obtained by bale (Examples 1 to 8). It can also be seen that the storage stability of the acrylic rubber veil is more preferable as the amount of ash is smaller (Examples 1 to 13). The acrylic rubber veil (M) of Example 13 is shown in Table 2-2 except that the specific gravity becomes 0.769 when the characteristic value of the crumb-shaped acrylic rubber after direct drying is measured without using a baler. It was the same as the result of Example 13. It was also important that the pH of the acrylic rubber was 6 or less for the storage stability.

[Regarding the particle size of the produced hydrous crumb]
Regarding the hydrous crumbs produced in the solidification steps in Examples 1 to 13 and Comparative Examples 1 and 2, (1) 710 μm to 6.7 mm (passes 6.7 mm without passing through 710 μm), (2) 710 μm to 4.75 mm (2) The ratio to the total amount of water-containing crumbs in the range of (3) 710 μm to 3.35 mm (passing 3.35 mm without passing through 710 μm) was measured using a JIS sieve. The results are shown below.

Example 1: (1) 91% by weight, (2) 91% by weight, (3) 84% by weight
Example 2: (1) 96% by weight, (2) 95% by weight, (3) 89% by weight
Example 3: (1) 91% by weight, (2) 85% by weight, (3) 79% by weight
Example 4: (1) 93% by weight, (2) 90% by weight, (3) 84% by weight
Example 5: (1) 95% by weight, (2) 93% by weight, (3) 90% by weight
Example 6: (1) 89% by weight, (2) 85% by weight, (3) 79% by weight
Example 8: (1) 94% by weight, (2) 93% by weight, (3) 87% by weight
Example 9: (1) 95% by weight, (2) 94% by weight, (3) 91% by weight
Example 10: (1) 89% by weight, (2) 86% by weight, (3) 83% by weight
Example 11: (1) 95% by weight, (2) 94% by weight, (3) 88% by weight
Example 12: (1) 93% by weight, (2) 93% by weight, (3) 90% by weight
Example 13: (1) 93% by weight, (2) 89% by weight, (3) 78% by weight
Comparative Example 1: (1) 17% by weight, (2) 3% by weight, (3) 0% by weight
Comparative Example 2: (1) 10% by weight, (2) 2% 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 9 to 13 in Table 2-2 and Comparative Examples 1 and 2). Further, the water-containing crumbs having a large specific ratio of (1) to (3) have a high ash removal rate at the time of dehydration, and the water-containing crumbs having a dehydration rate (water content) of 20% by weight (Examples 1 to 6) are dehydrated. It can be seen that the ash content is reduced and the water resistance of the acrylic rubber veil is improved as compared with the one having a rate (water content of 30% by weight) (Examples 7 to 8).

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 performed except that the concentration was changed from 0.7% by weight to 2% by weight (Reference Example 2), and the particle size ratios (1) to (3) of the hydrous crumb to be produced and the acrylic rubber veil. The amount of ash (4) was measured.

Reference Example 1: (1) 91% by weight, (2) 57% by weight, (3) 25% by weight, (4) 0.51% by weight
Reference example 2: (1) 92% by weight, (2) 75% by weight, (3) 42% by weight, (4) 0.40% by weight

For the acrylic rubber compositions containing the acrylic rubber veils (A) to (H) of Examples 1 to 8, 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 3.3 minutes 〇: Mooney scorch time t5 is 2 to 3.3 minutes ×: Mooney scorch time t5 is less than 2 minutes These acrylic rubber veils (A) )-(H), the cooling rate of the sheet-shaped dry rubber extruded from the screw type twin-screw extruder is actually as fast as about 200 ° C./hr as in Example 1, and both are 40 ° C./hr or more. Is.

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.

The acrylic rubber veils (A) to (H) obtained in Examples 1 to 8 and the crumb-shaped acrylic rubber (O) obtained in Comparative Example 2 as rubber samples were evaluated for the variation in gel amount. The results of the rubber veils (A) to (H) were all "◎", and the results of the crumb-shaped acrylic rubber (O) were "x".
This is because the acrylic rubber veils (A) to (H) are melt-kneaded and dried in a screw-type twin-screw extruder, so that the amount of gel insoluble in methyl ethyl ketone almost disappears and the amount of gel does not vary. It is presumed that this made it possible to significantly improve the Banbury workability.

On the other hand, the crumb-shaped acrylic rubber that has undergone emulsion polymerization and solidification washing under the conditions for producing the crumb-shaped acrylic rubber (O) of Comparative Example 2 is put into a screw-type twin-screw extruder under the same conditions as in Example 1 and extruded. It was found that the gel amount and the variation in the gel amount measured for the acrylic rubber obtained by drying could be reduced to almost the same level as the acrylic rubber veil (A), and the Banbury workability was remarkably improved.

[Releasability to mold]
The rubber compositions of the acrylic rubber veil (A) to (H) obtained in Examples 1 to 8 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 (A) to (H) 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 the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.5 to. It consists of acrylic rubber in the range of 3, and the gel amount of the insoluble methyl ethyl ketone is 50% by weight or less, the ash content is 0.3% by weight or less, and the total amount of sodium, sulfur, calcium, magnesium and phosphorus in the ash is 50% by weight or less. Acrylic rubber veil of 80% by weight or more.
Acrylic rubber consists of a bond unit consisting of 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, an epoxy group and a chlorine atom. The acrylic rubber veil according to claim 1, which comprises a binding unit composed of at least one type of reactive group-containing monomer selected from the group consisting of the same group and, if necessary, a bonding unit composed of other monomers.
The acrylic rubber veil according to claim 1 or 2, wherein the values obtained by arbitrarily measuring the gel amount of the insoluble matter 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, wherein the reactive group is an ionic reactive group.
The acrylic rubber veil according to any one of claims 1 to 4, wherein the weight average molecular weight (Mw) of the acrylic rubber is in the range of 1 million to 5 million.
The acrylic rubber veil according to any one of claims 1 to 5, wherein the ratio (Mz / Mw) of the z average molecular weight (Mz) and the weight average molecular weight (Mw) of the acrylic rubber is 1.3 or more.
The acrylic rubber veil according to any one of claims 1 to 6, wherein the solvent for measuring the molecular weight of acrylic rubber is a dimethylformamide-based solvent.
The acrylic rubber veil according to any one of claims 1 to 7, which has a specific gravity of 0.7 or more.
The acrylic rubber veil according to any one of claims 1 to 8, which has a water content of less than 1% by weight.
The acrylic rubber veil according to any one of claims 1 to 9, which is emulsion-polymerized using a phosphate ester salt or a sulfate ester salt as an emulsifier.
The acrylic rubber veil according to any one of claims 1 to 10, wherein the emulsion polymerized solution is coagulated by using an alkali metal salt or a metal salt of Group 2 of the periodic table as a coagulant and dried.
The acrylic rubber veil according to any one of claims 1 to 11, which is melt-kneaded and dried after solidification.
At least one selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester, at least one selected from the group consisting of (meth) acrylic acid ester, carboxyl group, epoxy group and chlorine atom. In the emulsification step of emulsifying a monomer component consisting of the reactive group-containing monomer and, if necessary, other monomers with water and an emulsifier.
An emulsion polymerization step in which polymerization is started in the presence of a redox catalyst consisting of an organic radical generator and a reducing agent, and a chain transfer agent is added in batches during the polymerization to continue the polymerization to obtain an emulsion polymerization solution.
A coagulation step of contacting the obtained emulsion polymerization solution with a coagulant to form a hydrous crumb,
A cleaning process to clean the generated hydrous crumbs,
The process of dehydrating the washed water-containing crumbs,
The drying process to dry the dehydrated hydrous crumb,
The veiling process to veil the dried rubber after drying,
The method for producing an acrylic rubber veil according to any one of claims 1 to 12, wherein the acrylic rubber veil is produced.
The method for producing an acrylic rubber veil according to claim 13, wherein the proportion of the hydrous crumb produced in the solidification step in the range of 710 μm to 6.7 mm is 30% by weight or more.
The method for producing an acrylic rubber veil according to claim 13 or 14, wherein the contact between the emulsion polymerization solution and the coagulant in the coagulation step is to add the emulsion polymerization solution to the agitated coagulation solution.
The method for producing an acrylic rubber veil according to any one of claims 13 to 15, wherein the stirred coagulant has a stirring number of 100 rpm or more.
The method for producing an acrylic rubber veil according to any one of claims 13 to 16, wherein the peripheral speed of the agitated coagulant is 0.5 m / s or more.
The method for producing an acrylic rubber veil according to any one of claims 13 to 17, 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 method for producing an acrylic rubber veil according to any one of claims 13 to 18, wherein the polymerization solution produced in the emulsion polymerization step is coagulated by contacting it with a coagulant containing an alkali metal salt or a metal salt of Group 2 of the periodic table. ..
The method for producing an acrylic rubber veil according to any one of claims 13 to 19, wherein the polymerization liquid produced in the emulsion polymerization step is coagulated with a coagulant to coagulate, and then melt-kneaded and dried.
A rubber composition comprising a rubber component containing the acrylic rubber veil according to any one of claims 1 to 12, a filler and a cross-linking agent.
The rubber composition according to claim 21, wherein the filler is a reinforcing filler.
The rubber composition according to claim 21, wherein the filler is carbon blacks.
The rubber composition according to claim 21, wherein the filler is silica.
The rubber composition according to any one of claims 21 to 24, wherein the cross-linking agent is an organic cross-linking agent.
The rubber composition according to any one of claims 21 to 25, wherein the cross-linking agent is a polyvalent compound.
The rubber composition according to any one of claims 21 to 26, wherein the cross-linking agent is an ionic cross-linking compound.
The rubber composition according to claim 27, wherein the cross-linking agent is an ionic cross-linking organic compound.
The rubber composition according to claim 27 or 28, wherein the cross-linking agent is a multivalent 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 27 to 29.
The rubber composition according to claim 29, 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 21 to 31, 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 21 to 32, further comprising an anti-aging agent.
The rubber composition according to claim 33, 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 12, 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 21 to 34.
The rubber crosslinked product according to claim 36, wherein the cross-linking of the rubber composition is performed after molding.
The rubber crosslinked product according to claim 36 or 37, wherein the cross-linking of the rubber composition is for performing primary cross-linking and secondary cross-linking.