JP2021123623A - Crosslinking composition - Google Patents

Abstract

To provide a crosslinking composition that allows for crosslinking not only at high temperature but also at relatively low temperature, or can accommodate a wide range of crosslinking temperatures.SOLUTION: A crosslinking composition has a polymer having a maleimide-derived constitutional unit, and a polyfunctional organic compound having at least two desorption groups in each molecule.SELECTED DRAWING: None

Description

The present invention relates to a cross-linking composition, and more specifically, a cross-linking composition capable of providing a cross-linking material having excellent cross-linking properties and normal physical characteristics at a wide range of cross-linking temperatures, and particularly having excellent cross-linking properties at low temperatures. It is possible to provide a cross-linked material having excellent normal physical properties at the time of cross-linking.

Generally, in order to use an elastomer as a final rubber product, a complicated operation called a cross-linking operation is required. Recently, in order to avoid these complicated cross-linking operations, it has been developed as an effective method to give the elastomeric copolymer itself a reactive group.

Examples of the elastomeric copolymer having a reactive group include an acrylic elastomer copolymerized with an acrylic acid ester, and active chlorine groups, epoxy groups, carboxyl groups and the like are known as reactive groups. ..

However, as seen in Patent Document 1 and Patent Document 2, acrylic elastomers also require not only primary cross-linking at high temperature but also secondary cross-linking for a long time, and in order to produce an efficient rubber product, it is necessary. Cross-linking operation under more mild conditions is required.

Patent No. 3599962 Patent No. 3617120

An object of the present invention is to provide a cross-linking composition capable of not only cross-linking at a high temperature but also at a relatively low temperature, that is, capable of cross-linking in a wide range of cross-linking temperatures.

As a result of diligent studies, the present inventors have solved the problem by cross-linking a polymer having a structural unit derived from maleimide with a polyfunctional organic compound containing at least two or more leaving groups in the molecule. Can be done.

Aspects of the present invention are as follows.
Item 1 A cross-linking composition containing a polymer having a structural unit derived from maleimide and a polyfunctional organic compound containing at least two or more leaving groups in the molecule.
Item 2. The cross-linking composition according to Item 1, wherein the polyfunctional organic compound containing at least two or more leaving groups in the molecule is an organic halogen compound containing two halogen atoms in the molecule.
Item 3. The cross-linking composition according to Item 1, wherein the polyfunctional organic compound containing at least two or more leaving groups in the molecule is an organic compound containing two sulfonyl groups in the molecule.
Item 4 Any of Items 1 to 3 in which the polymer having a structural unit derived from maleimide contains a structural unit derived from a (meth) acrylic acid alkyl ester and / or a structural unit derived from a (meth) acrylic acid alkoxyalkyl ester. The cross-linking composition described in Crab.
Item 5. A cross-linking material produced from the cross-linking composition according to any one of Items 1 to 4.

The cross-linking composition of the present invention can be used not only for cross-linking at high temperatures but also for a wide range of cross-linking temperatures that enable cross-linking at relatively low temperatures, and is particularly excellent in normal physical properties at low temperatures. It will be possible to industrially produce industrial rubber materials such as engine gaskets, oil hoses, air hoses, and O-rings, and rubber materials for automobiles that are manufactured more efficiently and with lower energy than before.

The present invention is made from a cross-linking composition containing a polymer having a structural unit derived from maleimide, a polyfunctional organic compound containing at least two or more leaving groups in the molecule, and a cross-linking composition. It is a cross-linking material.

In all the structural units of the polymer having the structural unit derived from maleimide, the content of the structural unit derived from maleimide is preferably 0.1% by mass or more, preferably 0.2% by mass or more. Is more preferably 0.3% by mass or more, the upper limit is preferably 10% by mass or less, more preferably 5% by mass or less, and 2.5% by mass or less. Especially preferable.

In the polymer having a structural unit derived from maleimide of the present invention, as another polymerization component, a monomer that can be generally produced by radical polymerization can be contained as a structural unit. Specifically, a structural unit derived from (meth) acrylic acid ester can be exemplified. The term "(meth) acrylic acid ester" means "acrylic acid ester or methacrylic acid ester", and the same applies to similar expressions in the present application.

Examples of the structural unit derived from the (meth) acrylic acid ester include a structural unit derived from the (meth) acrylic acid alkyl ester and / or a structural unit derived from the (meth) acrylic acid alkoxyalkyl ester, and carbon. A structural unit derived from a (meth) acrylic acid alkyl ester having an alkyl group of several 1 to 8, and a structural unit derived from a (meth) acrylic acid alkoxyalkyl ester having an alkoxyalkyl group having 2 to 8 carbon atoms. Preferably, a structural unit derived from a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 6 carbon atoms and / or a configuration derived from a (meth) acrylic acid alkoxyalkyl ester having an alkoxyalkyl group having 2 to 6 carbon atoms. It is more preferable to have a unit, and a structural unit derived from a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 4 carbon atoms and / or an alkoxyalkyl (meth) acrylic acid having an alkoxyalkyl group having 2 to 4 carbon atoms. It is particularly preferable to have a structural unit derived from an alkyl ester. The structural unit derived from the (meth) acrylic acid ester may be a structural unit derived from one or more (meth) acrylic acid esters.

Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, n-propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, and n- (meth) acrylic acid. Butyl, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, (meth) acrylate (Meta) acrylic acid esters such as 2-ethylhexyl and cyclohexyl (meth) acrylate can be exemplified, and ethyl (meth) acrylate and n-butyl (meth) acrylate are preferable.
Specific examples of the (meth) acrylic acid alkoxyalkyl ester include methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, and (meth). ) 2-propoxyethyl acrylate, 2-butoxyethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, 2-ethoxypropyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, (meth) ) (Meta) acrylic acid esters such as 3-ethoxypropyl acrylate, 4-methoxybutyl (meth) acrylate, 4-ethoxybutyl (meth) acrylate can be exemplified, and methoxyethyl (meth) acrylate can be used. It is preferable to have.

In all the structural units of the polymer having the structural unit derived from maleimide of the present invention, the content of the structural unit derived from the structural unit derived from acrylic acid ester is preferably 45% by mass or more, preferably 50% by mass or more. It is more preferably mass% or more, particularly preferably 60 mass% or more, and may be 75 mass% or more, 80 mass% or more, 85 mass% or more, 90 mass% or more. The upper limit is preferably 99.5% by mass or less, more preferably 99% by mass or less, and particularly preferably 98.5% by mass or less.

Further, the polymer having a structural unit derived from maleimide of the present invention may contain a structural unit derived from other monomers copolymerizable with these structural units in addition to the above structural units. Other structural units include a structural unit derived from an ethylenically unsaturated nitrile, a structural unit derived from a (meth) acrylamide-based monomer, a structural unit derived from an aromatic vinyl-based monomer, and a structural unit derived from a conjugated diene-based monomer. , Constituent units derived from non-conjugated diene, other structural units derived from olefins and the like.

Examples of the structural unit derived from the ethylenically unsaturated nitrile include a structural unit derived from a compound such as acrylonitrile, methacrylonitrile, α-methoxyacrylonitrile, and vinylidene cyanide.

The structural units derived from the (meth) acrylamide-based monomer include acrylamide, methacrylicamide, diacetoneacrylamide, diacetonemethacrylate, N-butoxymethylacrylamide, N-butoxymethylmethacrylate, N-butoxyethylacrylamide, and N-butoxy. Ethylmethacrylate, N-methoxymethylacrylamide, N-methoxymethylmethacrylate, N-propioxymethylacrylamide, N-propioxymethylmethacrylate, N-methylacrylamide, N-methylmethacrylate, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N, N-diethylacrylamide, N, N-diethylmethacrylate, N-methylolacrylamide, N-methylolmethacrylate, ethanecrylamide, crotonamide, silicic acid amide, maleindiamide, itacondiamide, Examples thereof include structural units derived from compounds such as methylmaleinamide, methylitaconamide, maleinimide, and itaconimide.

The structural units derived from aromatic vinyl-based monomers include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, α-fluorostyrene, and p-trifluoromethyl. Styrene, p-methoxystyrene, p-aminostyrene, p-dimethylaminostyrene, p-acetoxystyrene, styrene sulfonic acid or a salt thereof, α-vinylnaphthalene, 1-vinylnaphthalene-4-sulfonic acid or a salt thereof, 2- Examples thereof include structural units derived from compounds such as vinylfluorene, 2-vinylpyridine, 4-vinylpyridine, divinylbenzene, diisopropenylbenzene, and vinylbenzyl chloride.

The structural units derived from the conjugated diene-based monomer include 1,3-butadiene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,2-dichloro-1,3-butadiene, 2,3-Dichloro-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-neopentyl-1,3-butadiene, 2-bromo-1,3-butadiene, 2-cyano-1, Examples thereof include structural units derived from compounds such as 3-butadiene, 1,3-pentadiene, 1,3-hexadiene, chloroprene, and piperylene.

Examples of the structural unit derived from the non-conjugated diene include a structural unit derived from a compound of the non-conjugated diene such as 1,4-pentadiene, 1,4-hexadiene, etylidene norbornene, norbornadiene, and dicyclopentadiene. ..

As structural units derived from other olefin-based monomers, esters such as dicyclopentadienyl acrylate, dicyclopentadienyl methacrylate methacrylate, dicyclopentadienylethyl acrylate, and dicyclopentadienylethyl methacrylate Kinds, ethylene, propylene, vinyl chloride, vinylidene chloride, 1,2-dichloroethylene, vinyl acetate, vinyl fluoride, vinylidene fluoride, 1,2-difluoroethylene, vinyl bromide, vinylidene bromide, 1,2-dibromoethylene , Ethylene vinyl ether, butyl vinyl ether and other constituent units derived from compounds.

When a polymer having a structural unit derived from maleimide of the present invention contains a structural unit derived from these other copolymerizable monomers, the content in all the structural units is 0 to 15% by mass. It may be 0 to 10% by mass, and may be 0 to 5% by mass.

In a polymer having a structural unit derived from maleimide of the present invention, the content of the structural unit can be determined from the nuclear magnetic resonance spectrum of the obtained polymer.

<Method for producing a polymer having a structural unit derived from maleimide>
The polymer having a structural unit derived from maleimide used in the present invention can be obtained by polymerizing various monomers. Any of the monomers used may be a commercially available product, and there are no particular restrictions.

As the form of the polymerization reaction, any of an emulsion polymerization method, a suspension polymerization method, a massive polymerization method, and a solution polymerization method can be used, but from the viewpoint of ease of control of the polymerization reaction, conventionally known acrylic copolymers can be used. It is preferable to use an emulsion polymerization method under normal pressure, which is generally used as a method for producing a polymer.

In the case of polymerization by emulsion polymerization, a usual method may be used, and conventionally known polymerization initiators, emulsifiers, chain transfer agents, polymerization terminators and the like can be used.

The emulsifier used in the present invention is not particularly limited, and nonionic emulsifiers, anionic emulsifiers and the like generally used in the emulsion polymerization method can be used. Nonionic emulsifiers include, for example, polyoxyethylene alkyl ethers, polyoxyethylene alcohol ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polycyclic phenyl ethers, polyoxyalkylene alkyl ethers, sorbitan fatty acid esters, polyoxyethylene fatty acid esters and Examples thereof include polyoxyethylene sorbitan fatty acid ester, and examples of the anionic emulsifier include alkylbenzene sulfonate, alkyl sulfate ester salt, polyoxyethylene alkyl ether sulfate ester salt, polyoxyalkylene alkyl ether phosphate ester or its salt, and fatty acid salt. Etc., and one or more of these may be used. Typical examples of anionic emulsifiers include sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and triethanolamine dodecyl sulfate.

The amount of the emulsifier used in the present invention may be any amount generally used in the emulsion polymerization method. Specifically, it is preferably in the range of 0.01 to 10% by mass, more preferably 0.03% by mass or more, still more preferably 0.05% by mass or more, and more preferably, with respect to the amount of the charged monomer. It is 7% by mass or less, more preferably 5% by mass or less. When a reactive surfactant is used as the monomer component, it is not always necessary to add an emulsifier.

The polymerization initiator used in the present invention is not particularly limited, and a polymerization initiator generally used in the emulsion polymerization method can be used. Specific examples thereof include inorganic polymerization initiators typified by persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate, 2,2-di (4,5-di- (t-butylperoxy)). Cyclohexyl) propane, 1-di- (t-hexyl peroxy) 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, p-menthanhydroperoxide, 1,1,3,3-tetramethyl Butylhydroperoxide, t-butylcumyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, di (2-t-butylperoxyisopropyl) benzene, dicumyl peroxide, diisobutyryl peroxide , Di (3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, disuccinate peroxide, dibenzoyl peroxide, di (3-methylbenzoyl) peroxide, benzoyl (3-methylbenzoyl) peroxide , Diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, di-sec-butylperoxydi Carbonate, cumylperoxyneodecanate, 1,1,3,3-tetramethylbutylperoxyneodecanate, t-hexylperoxyneodecanate, t-butylperoxyneodecanate, t-hexylperoxypi Valate, t-butylperoxypivalate, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexa Nate, t-hexyl peroxy-2-ethylhexanate, t-butylperoxy-2-ethylhexanate, t-butylperoxylaurate, t-butylperoxy-3,5,5-trimethylhexanate, t-Hexyl peroxyisopropyl monocarbonate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy2-ethylhexyl monocarbonate, 2,5-dimethyl-2 , 5-Di (benzoylperoxy) hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxybenzoate, 2,5-dimethyl-2,5-di (t-butylperoxy) Organic peroxide-based polymerization initiator such as hexane, hydroperoxide, azobisisobutyronitrile, 4-4'-azobis (4-cyanovaleric acid), 2-2'-azobis [2- (2- (2-) Imidazoline-2-yl) Propane, 2-2'-azobis (Propane-2-carboamidine) 2-2'-azobis [N- (2-carboxyethyl) -2-methylpropaneamide, 2-2'-azobis {2- [1- (2-Hydroxyethyl) -2-imidazolin-2-yl] propane}, 2-2'-azobis (1-imino-1-pyrrolidino-2-methylpropane) and 2-2'- Examples thereof include azo-based initiators such as azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propanamide}. These polymerization initiators may be used alone or in combination of two or more.

The amount of the polymerization initiator used in the present invention may be any amount generally used in the emulsion polymerization method. Specifically, 0.01 to 5% by mass is preferable, more preferably 0.01% by mass or more, still more preferably 0.02% by mass or more, and more preferably 4% by mass or less with respect to the amount of the charged monomer. , More preferably 3% by mass or less.

Further, the organic peroxide and the inorganic peroxide as the polymerization initiator can be used as a redox-based polymerization initiator by combining with a reducing agent. The reducing agent used in combination is not particularly limited, but is not particularly limited, but is a compound containing a metal ion in a reduced state such as ferrous sulfate and ferrous naphthenate, a methane compound such as sodium methanesulfonate, and an amine such as dimethylaniline. Examples thereof include compounds, ascorbic acid and salts thereof, and reducing inorganic salts such as alkali metal salts of sulfurous acid and thiosulfate. These reducing agents can be used alone or in combination of two or more. The amount of the reducing agent used is preferably 0.0003 to 10.0 parts by mass with respect to 100 parts by mass of the charged monomer.

Chain transfer agents can be used as needed. Specific examples of the chain transfer agent include alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and n-stearyl mercaptan, 2,4-diphenyl-4. Xanthogen compounds such as −methyl-1-pentene, 2,4-diphenyl-4-methyl-2-pentene, dimethylxanthogen disulfide, diisopropylxanthogen disulfide, turpinolene, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiurammono Thiol compounds such as sulfides, phenolic compounds such as 2,6-di-t-butyl-4-methylphenol and styrated phenol, allyl compounds such as allyl alcohol, halogens such as dichloromethane, dibromomethane and carbon tetrabromide. Hydrocarbon compounds, vinyl ethers such as α-benzyloxystyrene, α-benzyloxyacrylonitrile, α-benzyloxyacrylamide, triphenylethane, pentaphenylethane, achlorine, metaacrolein, thioglycolic acid, thioallic acid, 2-ethylhexylthio Glycolate and the like can be mentioned, and one or more of these may be used. The amount of these chain transfer agents is not particularly limited, but is usually used in an amount of 0 to 5 parts by mass with respect to 100 parts by mass of the charged monomer.

Examples of the polymerization terminator include hydroxylamine, hydroxyamine sulfate, diethylhydroxyamine, hydroxyamine sulfonic acid and alkali metal salts thereof, and quinone compounds such as sodium dimethyldithiocarbamate and hydroquinone. The amount of the polymerization inhibitor used is not particularly limited, but is usually 0 to 2 parts by mass with respect to 100 parts by mass of all the monomers.

Further, the pH of the polymer obtained by the above method can be adjusted by using a base as a pH adjusting agent, if necessary. Specific examples of the base include sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, an inorganic ammonium compound, an organic amine compound and the like. The pH range is preferably pH 1 to 11, more preferably pH 1.5 or higher, further preferably pH 2 or higher, more preferably pH 10.5 or lower, still more preferably pH 10 or lower.

In addition to this, if necessary, polymerization auxiliary materials such as a particle size adjusting agent, a chelating agent, and an oxygen scavenger can be used.

The emulsion polymerization may be a batch type, a semi-batch type, or a continuous type. The polymerization time and polymerization temperature are not particularly limited. It can be appropriately selected from the type of polymerization initiator used, but generally, the polymerization temperature is 10 to 100 ° C. and the polymerization time is 0.5 to 100 hours.

The method for recovering the polymer obtained by the above method is not particularly limited, and a generally used method can be adopted. As an example of the method, a method of continuously or batch-supplying the polymerization solution to an aqueous solution containing a coagulant can be mentioned, and a coagulated slurry can be obtained by this operation. At that time, the temperature of the aqueous solution containing the coagulant is affected by the coagulation conditions such as the type and amount of the monomer used and the shearing force due to stirring, etc., so this cannot be specified uniformly, but in general, it is 50 ° C. The above is preferably in the range of 60 ° C to 100 ° C.

The coagulated slurry obtained by the above method is preferably washed with water in order to remove the coagulant. If the washing with water is not performed at all, or if the washing is insufficient, the ion residue derived from the coagulant may be precipitated in the molding process.

A polymer having a structural unit derived from maleimide can be obtained by removing water from the solidified slurry after washing with water and drying. The drying method is not particularly limited, but is generally dried using a flash dryer, a fluidized dryer, or the like. Further, a dehydration step using a centrifuge or the like may be performed before the drying step.

<Crosslink composition>
The cross-linking composition of the present invention contains at least a polymer having a structural unit derived from the above-mentioned maleimide and a cross-linking agent.

The cross-linking agent is a polyfunctional organic compound containing at least two or more leaving groups in the molecule, and must contain two or more leaving groups that can be eliminated in the nucleophilic substitution reaction. Can exemplify halogen groups (atoms) such as chlorine, bromine, and iodine, and sulfonic acid groups. Examples of the polyfunctional organic compound containing at least two or more elimination groups in the molecule include 1,6-dibromohexane, 1,6-dibromopropane, 1,6-diiodohexane, and 1,6-dichlorohexane. Dihaloalkyl compounds such as 1,9-dibromononane, 1,4-dibromopentane, 2,5-dibromohexane, dihaloorganic compounds containing aromatic rings such as p-xylene dibromid and p-xylene chloride chloride, and 1,2. It has two sulfonyl groups such as 1,4-butanediol dimethanesulfonate and organic compounds containing three or more leaving groups such as 5-tribromohexane and 1,2,5,6-tetrabromohexane. Compounds and the like can be exemplified. Specific examples of the sulfonyl group include a methanesulfonyl group, a p-toluenesulfonyl group, an o-nitrobenzenesulfonyl group, a trifluoromethanesulfonyl group and the like.
From the viewpoint of the vulcanization rate, a dihaloalkyl compound or a sulfonyl group-containing compound in which at least two or more leaving groups are in the primary position in the molecule is more preferable. The dihaloalkyl compound preferably has 1 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.

These cross-linking agents may be used alone or in combination of two or more. The amount of the cross-linking agent is preferably 0.1 part by mass or more, and more preferably 0.3 part by mass or more with respect to 100 parts by mass of the polymer having a structural unit derived from maleimide of the present invention. , 0.5 parts by mass or more, preferably 20 parts by mass or less, more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less.

In addition, a base can be added to the cross-linking composition of the present invention as needed.

Specific examples of the base include inorganic bases such as alkaline earth metals or alkali metal hydroxides, carbonates and acetates, and organic bases such as amines, such as potassium carbonate, sodium carbonate and cesium carbonate. , Inorganic bases such as potassium tert-butoxide and sodium tert-butoxide and organic bases such as triethylamine, N, N-diisopropylethylamine and diazabicycloundecene can be used. It is more preferable to use a base having low nucleophilicity as the type of base.

The amount of the base is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and 3 parts by mass with respect to 100 parts by mass of the polymer having a structural unit derived from maleimide of the present invention. It is particularly preferably parts or more, preferably 20 parts by mass or less, more preferably 18 parts by mass or less, and particularly preferably 15 parts by mass or less. In particular, if the amount of base is too small, the cross-linking reaction may not proceed sufficiently.

In addition, the cross-linking composition of the present invention includes other additives usually used in the art, such as lubricants, softeners, antistatic agents, light stabilizers, fillers, reinforcing agents, plasticizers, and processing aids. Agents, pigments, colorants, antistatic agents, foaming agents and the like can be arbitrarily blended.

As the filler, a known filler can be used, and specifically, calcium carbonate, talc, silica, clay, carbon fiber, glass fiber, carbon black, titanium oxide, magnesium oxide, hydrotalcite, and hydroxide. Examples thereof include magnesium, antimony oxide, zinc oxide and carbon black, and silica and carbon black are preferable.

The blending amount of the filler may be 15 to 100 parts by mass with respect to 100 parts by mass of the polymer having a structural unit derived from maleimide. It is preferably 20 to 80 parts by mass.

Examples of the softener include lubricating oil, process oil, coal tar, castor oil, stearic acid, calcium stearate and the like.

The blending amount of the softener may be 0.3 to 10 parts by mass with respect to 100 parts by mass of the polymer having a structural unit derived from maleimide. It is preferably 0.5 to 5 parts by mass.

Examples of the antiaging agent include amines, phosphates, quinolines, cresols, phenols, dithiocarbamate metal salts and the like, and amines such as diphenylamine derivatives and phenylenediamine derivatives are preferable.

The blending amount of the antiaging agent may be 0.3 to 10 parts by mass with respect to 100 parts by mass of the polymer having a structural unit derived from maleimide. It is preferably 0.5 to 5 parts by mass.

Further, it is also possible to blend with rubber, resin, etc., which are usually performed in the art, without departing from the spirit of the present invention. Examples of the rubber used in the present invention include butadiene rubber, styrene-butadiene rubber, isoprene rubber, natural rubber, acrylonitrile-butadiene rubber, acrylonitrile-butadiene-isoprene rubber, ethylene-propylene-diene rubber, epichlorohydrin rubber and the like. Examples of resins include PMMA (polymethylmethacrylate) resin, PS (polystyrene) resin, PUR (polyurethane) resin, PVC (polyvinyl chloride) resin, EVA (ethylene / vinyl acetate) resin, and AS (styrene / acrylonitrile). ) Resin, PE (polyethylene) resin and the like.

The total amount of the rubber and the resin to be blended is 50 parts by mass or less, preferably 10 parts by mass or less, and more preferably 1 part by mass or less with respect to 100 parts by mass of the polymer having the structural unit derived from the maleimide of the present invention. be.

As a method for blending the cross-linking composition of the present invention, any means conventionally used in the field of polymer processing, for example, an open roll, a Banbury mixer, various kneaders and the like can be used.

As the compounding procedure, it can be carried out by a usual procedure performed in the field of polymer processing. For example, it can be carried out by first kneading only the polymer, then preparing an A kneading compound containing a compounding agent other than the cross-linking agent, and then performing B-kneading by adding the cross-linking agent and the cross-linking accelerator.

The cross-linking composition of the present invention can be made into a cross-linked product by heating. The cross-linking time varies depending on the temperature, but is usually between 0.5 and 300 minutes. Cross-linking molding is performed in the case of integrally performing cross-linking and molding, in the case of forming a cross-linked product by heating the previously molded acrylic copolymer-containing composition again, or for molding the cross-linked product by heating first. It may be any of the cases where the processing is applied to. As a specific method of cross-linking molding, any method such as compression molding by a mold, injection molding, steam can, air bath, infrared rays, or heating by microwave can be used.

In order to obtain a crosslinked product in which cross-linking has proceeded sufficiently using a general acrylic elastomer, it is necessary to heat at 160 to 200 ° C., but the cross-linking composition of the present invention has a wide temperature range ( For example, it can be obtained as a crosslinked product at (100 ° C. to 200 ° C.), and is also preferable in that it can be obtained as a crosslinked product in which cross-linking is sufficiently advanced even at a relatively low temperature (100 to 150 ° C.). It can also be described as a method for producing a crosslinked material at a low temperature (100 to 150 ° C.) using a material.

The present invention will be specifically described with reference to Examples and Comparative Examples. However, the present invention is not limited thereto.
In this example and the comparative example, the production of a polymer having a structural unit derived from maleimide, the cross-linking composition containing the obtained polymer having a structural unit derived from maleimide and a cross-linking agent, and the cross-linking composition. The physical properties of the crosslinked material produced using the above were evaluated.

[Examples 1 to 4, Comparative Examples 1 to 4]
(Production of Polymer A)
In a polymerization reactor equipped with a thermometer, agitator, nitrogen introduction tube and decompression device, 200 parts by mass of water, 1.7 parts by mass of polyoxyalkylene alkyl ether phosphate, 49.2 parts by mass of ethyl acrylate as a monomer, After 49.2 parts by mass of n-butyl acrylate and 1.6 parts by mass of maleimide were charged, degassing under reduced pressure and substitution with nitrogen were repeated to sufficiently remove oxygen, 0.1 part by mass of sodium ascorbate and potassium persulfate 0. 1 part by mass was added to start the emulsion polymerization reaction at normal pressure and normal temperature, the reaction was continued until the polymerization conversion rate reached 95%, and 0.0075 parts by mass of hydroquinone was added to terminate the polymerization. The obtained emulsion polymerization solution was coagulated with an aqueous sodium sulfate solution, washed with water and dried to obtain a polymer A.

[Comparative Example 2]
(Production of Acrylic Copolymer B)
From Example 1, the monomer to be charged and the amount thereof were changed to 49.2 parts by mass of ethyl acrylate, 49.2 parts by mass of n-butyl acrylate, and 1.4 parts by mass of monoethyl fumarate. The same procedure was carried out to obtain an acrylic copolymer B.

[Comparative Example 3]
(Manufacture of Acrylic Copolymer C)
From Example 1, the monomer to be charged and the amount thereof were changed to 79.2 parts by mass of ethyl acrylate, 19.0 parts by mass of n-butyl acrylate and 1.4 parts by mass of vinyl monochloroacetate. The same procedure was carried out to obtain an acrylic copolymer C.

[Comparative Example 4]
(Manufacture of Acrylic Copolymer D)
From Example 1, the amount of the monomer to be charged is 52.1 parts by mass of ethyl acrylate, 23.0 parts by mass of 2-methoxyethyl acrylate, 23.0 parts by mass of n-butyl acrylate and 1.9 parts of allyl glycidyl ether. Acrylic copolymer D was obtained in the same manner as in Example 1 except that the parts were changed to parts by mass.

(Manufacturing of cross-linking composition)
First, each of the compounding agents shown in Tables 1 and 2 was kneaded with a kneader at 120 ° C. to prepare an A kneading compound. This A kneading compound was kneaded with an open roll at room temperature to prepare a B kneading compound. In the table, A is a raw material for the A kneading compound, and B is a raw material to be blended with the A kneading compound when the B kneading compound is prepared. The unit for the compounding agents in Tables 1 and 2 is parts by mass.

(Crosslink test)
For the obtained cross-linking composition, the maximum torque (MH) was calculated by measuring the vulcanization curve for 10 minutes at 180 ° C and 130 ° C using a curast meter "Curast Meter 7" (manufactured by JSR Trading Co., Ltd.). bottom. The results are shown in Tables 1 and 2.

(Preparation of uncrosslinked sheet)
Using each of the cross-linking compositions obtained above, an uncross-linked sheet having a thickness of 2 to 2.5 mm was prepared.

(Preparation of cross-linked material (cross-linked product))
The uncrosslinked sheet obtained above was pressed at 130 ° C. for 30 minutes to obtain a crosslinked product.

(Test of normal physical characteristics)
Using the obtained crosslinked product, a tensile test and a hardness test were evaluated using AGS-5KNY manufactured by Shimadzu Corporation. The tensile test was performed according to the method described in JIS K 6251, and the hardness test was performed according to the method described in JIS K 6253. The results are shown in Tables 1 and 2.

Table 1 shows the results of the examples obtained by each of the above test methods, and Table 2 shows the test results of the comparative examples.
In each table, the cross-linking test is the maximum torque by the curast meter, 100% modulus is the stress when stretched 100%, TB is the strength specified in the tensile test of JIS K6251, HS is the type A durometer specified in the hardness test of JIS K6253. It means hardness respectively.

The compounding agents in the table are described below.
* 1 Kao Chemical Co., Ltd. "Semi-cured beef tallow fatty acid potassium soap"
* 2 Kao Chemical Co., Ltd. "Semi-cured beef tallow fatty acid soda soap"
* 3 "Ferric dimethyldithiocarbamate" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
* 4 "Zinc dimethyldithiocarbamate" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.

As shown in Table 1, the cross-linking composition of the present invention has a large maximum torque (MH) at 130 ° C. at a low temperature in the curastometer test, and the cross-linking proceeds faster than in the comparative example. It was shown in Examples 1 to 4 that the crosslinked product is excellent in normal physical properties because it has excellent properties and its crosslinked product has a large 100% modulus and hardness (Hs).
In Comparative Example 1, even when a polymer having a structural unit derived from maleimide was used, cross-linking did not proceed unless a cross-linking agent was added.
In Comparative Example 2, the maximum torque (MH) at 130 ° C. as the cross-linking composition is small, and the cross-linking material has high strength (TB) but low 100% modulus and hardness (Hs), and the cross-linking proceeds sufficiently. It is presumed that it has not been done.
In Comparative Examples 3 and 4, the maximum torque (MH) at 130 ° C. as the cross-linking composition was small, and 100% modulus, strength (TB) and hardness (Hs) were low as the cross-linking material, and the cross-linking proceeded sufficiently. It is presumed that it has not been done.

The cross-linking composition containing the polymer having a structural unit derived from maleimide of the present invention and the polyfunctional organic compound containing at least two or more desorbing groups in the molecule and the cross-linked product thereof can be obtained at a low temperature for a short time. It is possible to efficiently manufacture various rubber products and resin product materials with low energy due to the excellent normal physical properties at the time of cross-linking.

Claims (5)

A cross-linking composition containing a polymer having a structural unit derived from maleimide and a polyfunctional organic compound containing at least two or more leaving groups in the molecule. The cross-linking composition according to claim 1, wherein the polyfunctional organic compound containing at least two or more leaving groups in the molecule is an organic halogen compound containing two halogen atoms in the molecule. The cross-linking composition according to claim 1, wherein the polyfunctional organic compound containing at least two or more leaving groups in the molecule is an organic compound containing two sulfonyl groups in the molecule. Any of claims 1 to 3, wherein the polymer having a structural unit derived from maleimide contains a structural unit derived from a (meth) acrylic acid alkyl ester and / or a structural unit derived from a (meth) acrylic acid alkoxyalkyl ester. The cross-linking composition according to. A cross-linking material produced from the cross-linking composition according to any one of claims 1 to 4.