JP7169785B2 - Chlorinated polyolefin composition - Google Patents

Description

The present invention relates to chlorinated polyolefin compositions. More specifically, the present invention relates to a chlorinated polyolefin composition excellent in flex crack resistance and a molded product obtained by cross-linking the composition.

Chlorinated polyolefin is a chlorine-containing polymer that does not have unsaturated bonds in its main chain. It is used as a molding material for wire coating materials and rollers.
Japanese Patent Application Laid-Open No. 2017-014480 (Patent Document 1) discloses a vinyl chloride resin composition for automotive interiors containing a vinyl chloride resin and an epoxycyclohexanedicarboxylic acid diester and using an organic peroxide as an epoxidizing agent. wherein the epoxycyclohexanedicarboxylic acid diester is 4,5-epoxycyclohexane-1,2-dicarboxylic acid diester, and the ratio of linear alkyl groups to the total amount of alkyl groups constituting the dicarboxylic acid diester ( (molar ratio) is 50 to 99% for automotive interiors.

Japanese Patent Application Laid-Open No. 9-317701 (Patent Document 2) discloses that a chlorinated polyethylene composition comprising chlorinated polyethylene having a chlorine content of about 20 to 50% by mass and hydrotalcite is mixed with an organic peroxide (dicumyl peroxide ), which is excellent in water resistance, bleaching resistance, bending resistance, gas permeation resistance and water contamination resistance, is disclosed.

JP 2017-014480 A JP-A-9-317701

In Patent Documents 1 and 2, an organic peroxide is used as a cross-linking agent. In particular, flex cracks are likely to occur in molded articles obtained by cross-linking chlorinated polyolefins with organic peroxides.

Accordingly, it is an object of the present invention to provide a chlorinated polyolefin composition having excellent flex crack resistance without lowering mechanical strength and abrasion resistance, and a molded article obtained by cross-linking the composition. aim.

As a result of extensive studies, the inventors of the present invention have found that a composition comprising chlorinated polyolefin blended with a cyclohexenecarboxylic acid ester and an organic peroxide can achieve the object, and completed the present invention.
That is, the present invention relates to the following chlorinated polyolefin compositions [1] to [13], molded articles [14], and methods for producing molded articles [15].

[1] A chlorinated polyolefin composition comprising a chlorinated polyolefin (A), a cyclohexenecarboxylic acid ester (B) and an organic peroxide (F).
[2] The chlorinated polyolefin composition as described in [1] above, wherein the chlorinated polyolefin (A) is chlorinated polyethylene.
[3] The chlorinated polyolefin composition as described in [1] or [2] above, wherein the cyclohexene carboxylate (B) is a compound in which two hydrogen atoms of cyclohexene are substituted with a carboxylate.
[4] The chlorinated polyolefin composition as described in any one of [1] to [4] above, wherein the cyclohexenecarboxylic acid ester (B) is 4-cyclohexene-1,2-dicarboxylic acid bis(2-ethylhexyl).
[5] The chlorinated polyolefin composition according to any one of [1] to [4] above, containing 5 to 50 parts by mass of the cyclohexenecarboxylic acid ester (B) with respect to 100 parts by mass of the chlorinated polyolefin (A).
[6] Any one of claims 1 to 5, wherein the organic peroxide (F) is contained in an amount of 0.4 parts by mass or more and 8.0 parts by mass or less with respect to the chlorinated polyolefin (A) in terms of 100% purity. A chlorinated polyolefin composition as described.
[7] The chlorinated polyolefin composition as described in any one of the preceding Items 1 to 6, further comprising a curing agent (D).
[8] The chlorinated polyolefin composition as described in [7] above, wherein the curing agent (D) is diallyl 1,2-benzenedicarboxylate or bis(2-propenyl) 1,2-cyclohexanedicarboxylate.
[9] The chlorinated polyolefin composition according to any one of the preceding Items 1 to 8, further comprising an acid acceptor (E).
[10] The chlorinated polyolefin composition as described in [9] above, wherein the acid acceptor (E) is hydrotalcite, an oxide of a Group II metal of the periodic table or a hydroxide of a Group II metal of the periodic table.
[11] The organic peroxide (F) is 2,5-bis(t-butylperoxy)-2,5-dimethyl-3-hexyne or 2,5-di(t-butylperoxy)-2,5 - The chlorinated polyolefin composition according to any one of the preceding items 1 to 10, which is dimethyl-hexane.
[12] The chlorinated polyolefin composition as described in any one of the preceding Items 1 to 11, further comprising a reinforcing material (G).
[13] The chlorinated polyolefin composition as described in [12] above, wherein the reinforcing material (G) is carbon black or silica.
[14] A molded article obtained by molding and cross-linking the chlorinated polyolefin composition according to any one of [1] to [13] above.
[15] A method for producing a molded article, which comprises molding and crosslinking the chlorinated polyolefin composition according to any one of [1] to [13] above.

A molded article obtained by cross-linking the chlorinated polyolefin composition of the present invention containing cyclohexene carboxylic acid ester and organic peroxide exhibits excellent flex crack resistance without lowering mechanical strength and abrasion resistance. have.

Hereinafter, embodiments of the present invention will be described in detail.
First, each component of the chlorinated polyolefin composition of the present embodiment will be described.
The chlorinated polyolefin composition comprises (A) a chlorinated polyolefin, (B) a cyclohexene carboxylic acid ester and (F) an organic peroxide. It may also contain (C) a plasticizer, (D) a curing agent, (E) an acid acceptor, and (G) a reinforcing material.

(A) Chlorinated polyolefin Chlorinated polyolefin (A) is obtained by chlorinating polyolefin. Polyolefins include homopolymers of α-olefins having 2 to 10 carbon atoms such as polyethylene and polypropylene (hereinafter sometimes abbreviated as PP), or copolymers of two or more α-olefins, such as Block copolymerized PP, random PP and the like can be mentioned. Among these, polyethylene is particularly preferred in terms of productivity, mechanical strength, flexibility and crosslinkability during chlorination.

Chlorination of the polyethylene can be carried out, for example, by a method of introducing chlorine gas into an aqueous suspension of polyethylene. The lower limit of the chlorine content of chlorinated polyethylene is 20% by mass or more, preferably 25% by mass or more, and more preferably 28% by mass or more. Also, the upper limit of the chlorine content is 50% by mass or less, preferably 40% by mass or less, and more preferably 35% by mass or less. Flexibility is obtained when the chlorine content is 20% by mass or more. On the other hand, good flexibility and heat resistance can be obtained at 50% by mass or less.

The chlorinated polyethylene has a Mooney viscosity ML ₍₁₊₄₎ at 121° C. that is preferably 30 or higher, more preferably 50 or higher, and even more preferably 55 or higher. The upper limit of the Mooney viscosity ML ₍₁₊₄₎ at 121° C. of chlorinated polyethylene is preferably 140 or less, more preferably 120 or less, still more preferably 110 or less.
If the Mooney viscosity ML ₍₁₊₄₎ of the chlorinated polyethylene at 121°C is within the above range, it is easy to obtain molded articles that are excellent in workability, mechanical strength, wear resistance, flex crack resistance, etc. .

The chlorinated polyethylene in the present invention is preferably amorphous. Here, the term “amorphous” means that the heat of crystal fusion measured by heating a measurement sample from room temperature at a rate of 10° C. per minute using a differential scanning calorimeter is 2.0 J/g or less. means

(B) Cyclohexene carboxylate The chlorinated polyolefin composition of the present invention contains a cyclohexene carboxylate (B) as a plasticizer. Cyclohexenecarboxylic acid ester (B) is preferably a compound in which at least one hydrogen atom of cyclohexene is substituted with a carboxylic acid ester, more preferably a cyclohexene dicarboxylic acid ester in which two hydrogen atoms are substituted with a carboxylic acid ester. be.
Compounds in which one of the hydrogen atoms of cyclohexene is substituted with a carboxylic acid ester include, for example, nonyl 2-cyclohexene-1-carboxylate, nonyl 3-cyclohexene-1-carboxylate, 2-cyclohexene-1-carboxylic acid (2- ethylhexyl), 3-cyclohexene-1-carboxylic acid (2-ethylhexyl).

Compounds in which two of the hydrogen atoms are substituted with carboxylic acid esters include, for example, bis(2-ethylhexyl) 4-cyclohexene-1,2-dicarboxylate (hereinafter sometimes abbreviated as DOTH), 3-cyclohexene- bis(2-ethylhexyl) 1,2-dicarboxylate, bis(2-ethylhexyl) 4-cyclohexene-1,3-dicarboxylate, bis(nonyl) 4-cyclohexene-1,2-dicarboxylate, 3-cyclohexene-1 , 2-dicarboxylic acid bis(nonyl) and 4-cyclohexene-1,3-dicarboxylic acid bis(nonyl).
Among these compounds, DOTH and bis(nonyl) 4-cyclohexene-1,2-dicarboxylate are preferred, and DOTH is more preferred.

In the composition of the present invention, the amount of the cyclohexene carboxylate (B) compounded is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, relative to 100 parts by mass of the chlorinated polyolefin (A). and more preferably 15 parts by mass or more. Moreover, the upper limit is preferably 50 parts by mass or less, more preferably 35 parts by mass or less, and still more preferably 30 parts by mass or less with respect to 100 parts by mass of the chlorinated polyolefin (A). When (B) the cyclohexenecarboxylic acid ester is within this range, a molded article having appropriate hardness can be obtained.

(C) Plasticizer The chlorinated polyolefin composition in one embodiment of the present invention may contain a plasticizer (C) other than the cyclohexenecarboxylic acid ester (B). Plasticizers commonly used for polyvinyl chloride can be used as the plasticizer (C). Specifically, alkylsulfonic acid phenyl ester (trade name Mesamoll (registered trademark)); dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, 2-ethylhexyl phthalate (hereinafter sometimes abbreviated as DOP), isononyl phthalate, octyldecyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate, n-octyl tetrahydrophthalate, di-2-ethylhexyl tetrahydrophthalate, tetrahydrofuranic acid Phthalate plasticizers such as diisodecyl; aliphatic monobasic ester plasticizers such as butyl oleate and chrycerin monooleate; dibutyl adipate, di-n-hexyl adipate, di-2-adipate Fats such as ethylhexyl, diisononyl adipate, diisodecyl adipate, dialkyl adipate 610, dibutyl diglycol adipate, di-2-ethylhexyl azelate, di-n-hexyl azelate, dibutyl sebacate, di-2-ethylhexyl sebacate Group dibasic ester plasticizers; trimellitate ester plasticizers such as trialkyl trimellitate (C4-11) and trioctyl trimellitate; dibasic acids such as adipic acid, azelaic acid, sebacic acid, and phthalic acid Polyester plasticizers such as propylene glycol adipate and -1,3-butylene glycol adipate, which are polymers of glycol, glycerol, monobasic acid, etc.; triethyl phosphate, tributyl phosphate, tri-2-phosphate Ethylhexyl, triphenyl phosphate, tricresyl phosphate, trichloroethyl phosphate, trisdichloropropyl phosphate, tributoxyethyl phosphate, tris(β-chloropropyl) phosphate, octyldiphenyl phosphate, tris(isopropylphenyl) phosphate, cresyl phosphate Phosphate plasticizers such as diphenyl phosphate; chlorinated paraffin plasticizers and the like can be used.

The blending amount of the plasticizer (C) is preferably 50 parts by mass or less, more preferably 35 parts by mass or less, and still more preferably 30 parts by mass or less with respect to 100 parts by mass of the chlorinated polyolefin (A). be.
If the mixing ratio of the plasticizer (C) to 100 parts by mass of the chlorinated polyolefin (A) is 50 parts by mass or less, a molded article with appropriate hardness can be obtained.

(D) Curing Agent The chlorinated polyolefin composition in one embodiment of the present invention comprises a curing agent (D). A compound having two or more ethylenic double bonds is preferable as the curing agent (D). For example, trimethylolpropane trimethacrylate, triallyl cyanurate, divinylbenzene, 2,4,6-tris(allyloxy)-1,3,5-triazine, 1,3,5-triallyl-1,3,5-triazine -2,4,6(1H,3H,5H)-trione (TAIC; registered trademark), diallyl phthalate (hereinafter sometimes abbreviated as DAP), diallyl isophthalate, diallyl terephthalate, 2-ethyl- 2-hydroxymethyl-1,3-propanediol trimethacrylate, 1,3-butylene glycol dimethacrylate, trimethylolpropane trimethacrylate, diallyl 1,2-cyclohexanedicarboxylate (hereinafter abbreviated as DAC) There is.), etc.

Among these curing agents, specifically, 2,4,6-tris(allyloxy)-1,3,5-triazine, TAIC (registered trademark), 2-ethyl- 2-hydroxymethyl-1,3-propanediol trimethacrylate, 1,3-butylene glycol dimethacrylate, DAP, diallyl isophthalate, diallyl terephthalate, DAC are preferred.
These curing agents (D) may be used alone or in combination of two or more.

In one embodiment of the present invention, when the curing agent (D) blended in the chlorinated polyolefin composition is trifunctional, the amount of the curing agent (D) per 100 parts by mass of the chlorinated polyolefin (A) is the lower limit. is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, still more preferably 2.0 parts by mass or more, the upper limit is preferably 7.0 parts by mass or less, and more It is preferably 5.0 parts by mass or less, more preferably 4.0 parts by mass or less.
When the curing agent (D) is bifunctional, the lower limit of the amount of the curing agent (D) blended with respect to 100 parts by mass of the chlorinated polyolefin (A) is preferably 2.0 parts by mass or more, more preferably It is 4.0 parts by mass or more, more preferably 5.0 parts by mass or more, and the upper limit is preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and still more preferably 30 parts by mass or less. be.
When the amount of the curing agent (D) is 0.5 parts by mass or more in the case of trifunctionality, and 2.0 parts by mass or more in the case of bifunctionality, the crosslinking reaction of the chlorinated polyolefin composition proceeds rapidly. , a compact having excellent mechanical strength and wear resistance can be easily obtained. On the other hand, if the amount of the curing agent (D) is 7.0 parts by mass or less in the case of trifunctional, and 40 parts by mass or less in the case of bifunctional, a crosslinked molded article can be easily formed from the chlorinated polyolefin composition. Obtainable.

(E) Acid Acceptor The chlorinated polyolefin composition in one embodiment of the present invention comprises an acid acceptor (E). As the acid acceptor (E), hydrotalcite, tribasic lead sulfate, oxides, hydroxides, carbonates, carboxylates, silicates, borates, or periodic Examples include oxides, basic carbonates, basic carboxylates, basic phosphites, basic sulfites, etc. of Table IV metals. Specific examples include synthetic hydrotalcite, magnesium oxide, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, slaked lime, quicklime, calcium carbonate, calcium silicate, calcium stearate, barium stearate, magnesium phosphite, and phosphorous acid. calcium, tin oxide, litharge, red lead, white lead, dibasic lead phthalate, dibasic lead carbonate, basic lead phosphite, basic lead sulfite, tribasic lead sulfate, etc., preferably hydro It is talcite.

The lower limit of the mixing ratio of the acid acceptor (E) to 100 parts by mass of the chlorinated polyolefin (A) is preferably 2.0 parts by mass or more, more preferably 5.0 parts by mass or more, and still more preferably 7. 0 parts by mass or more, and the upper limit is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and still more preferably 15 parts by mass or less. If the blending ratio is 2.0 parts by mass or more, desired heat resistance is obtained, and if it is 30 parts by mass or less, mechanical strength is obtained.

(F) organic peroxide
The type of organic peroxide (F) to be blended in the chlorinated polyolefin composition of the present invention is not particularly limited as long as the composition can undergo a cross-linking reaction. For example, stearoyl peroxide, lauroyl peroxide, benzoyl peroxide, 4-methylbenzoyl peroxide, 1,1-bis(t-butylperoxy) 2-methylcyclohexane, 1,1-bis(t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1- Bis(t-butylperoxy)cyclohexane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxyisopropylmonocarbonate, t-butylperoxy- 2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxybenzoate, n-butyl-4,4-bis(t- butylperoxy)valerate, di-t-butylperoxyisophthalate, α,α'-bis(t-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(t -butylperoxy)hexane, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxyl)hexyne-3 (trade name: Perhexyne (registered trademark) 25B-40), 2 ,5-di(t-butylperoxy)-2,5-dimethyl-hexane (trade name: Perhexa (registered trademark) 25B). These organic peroxides may be used singly or in combination of two or more.

Among these organic peroxides, those having a 1-minute half-life temperature of 130° C. or higher are preferred. If the 1-minute half-life temperature is 130° C. or higher, a crosslinked molded product can be easily obtained.
Here, the 1-minute half-life temperature of the organic peroxide is the temperature at which the organic peroxide (F) decomposes and the initial amount of active oxygen halves in 1 minute. The measurement method is not particularly limited, but for example, the half-life of an organic peroxide at a peroxide concentration of 0.10 mol/L is determined at multiple temperatures in a solvent (such as benzene) that is relatively inert to radicals. , can be determined by the method of plotting those data.

In the chlorinated polyolefin composition of the present invention, the lower limit of the amount of the organic peroxide (F) blended with respect to 100 parts by mass of the chlorinated polyolefin (A) is preferably 0.4 parts by mass or more in terms of 100% purity, It is more preferably 0.8 parts by mass or more, still more preferably 1.6 parts by mass or more, and the upper limit is preferably 8.0 parts by mass or less, more preferably 4.0 parts by mass or less, and further Preferably, it is 2.4 parts by mass or less. When the amount of the organic peroxide (F) is 0.4 parts by mass or more in terms of 100% purity, the cross-linking reaction of the composition proceeds rapidly, and a molded article having excellent mechanical strength and abrasion resistance can be obtained. Cheap. On the other hand, if the blending amount of the organic peroxide (F) in terms of 100% purity is 8.0 parts by mass or less, a molded article can be easily obtained from the composition.
In the chlorinated polyolefin composition of the present invention, the amount of the organic peroxide (F) blended with respect to 100 parts by mass of the cyclohexene carboxylate (B) is 0.8 parts by mass or more and 160 parts by mass or less in terms of 100% purity. , preferably 2.3 to 40 parts by mass, more preferably 5.3 to 16 parts by mass.

(G) Reinforcing material The reinforcing material (G) blended in the chlorinated polyolefin composition in one embodiment of the present invention is not particularly limited, but specific examples include carbon black, silica, calcium carbonate, talc, clay, and water. Examples include aluminum oxide, magnesium hydroxide, magnesia, and the like. These reinforcing materials may be surface-treated for the purpose of antistatic or the like. Among these, reinforcing materials having excellent abrasion resistance are preferable, and carbon black and silica are more preferable.

The lower limit of the mixing ratio of the reinforcing material (G) to 100 parts by mass of the chlorinated polyolefin (A) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 20 parts by mass or more. , the upper limit is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less. The hardness of the molded article obtained when the blending ratio is 5 parts by mass or more and 100 parts by mass or less is good.

The chlorinated polyolefin composition of the present invention may contain various additives such as stabilizers, anti-aging agents, processing aids, thickeners, flame retardants, pigments, etc. in the technical field, as long as they do not impair the properties of the present invention. can be added

[Chlorinated polyolefin composition and molded article thereof]
The chlorinated polyolefin composition of the present invention can be produced by using a known mixer such as an open roll mixer, a Banbury mixer, a pressurized kneader, an intermixer, etc., which are commonly used for rubber mixing. .

The chlorinated polyolefin composition of the present invention can be molded by various molding methods such as compression molding, injection molding, transfer molding, extrusion molding, etc., and crosslinked to obtain a molded product. Moreover, various methods such as hot air crosslinking, microwave crosslinking, and electron beam crosslinking can be used as the method for crosslinking the extruded product.
The cross-linking temperature of the molded article of the present invention depends on the thermal decomposition temperature of the organic peroxide used, but the lower limit thereof is preferably 130° C. or higher, more preferably 140° C. or higher, and still more preferably 150° C. or higher. is. The upper limit of the cross-linking temperature of the molded article of the present invention is preferably 200° C. or lower, more preferably 190° C. or lower, and still more preferably 180° C. or lower. If the temperature is 140° C. or higher, appropriate cross-linking can be achieved. Also, if the temperature is 190° C. or lower, the generated acid can be trapped by the acid acceptor, and appropriate cross-linking can be achieved.
The crosslinking time condition of the molded article of the present invention depends on the thermal decomposition temperature of the organic peroxide used, but the lower limit is preferably 10 minutes or more, more preferably 15 minutes or more, and still more preferably 20 minutes. That's it. The upper limit of the crosslinking time condition for the molded article of the present invention is preferably 50 minutes or less, more preferably 45 minutes or less, and still more preferably 40 minutes or less. If the cross-linking time is 10 minutes or longer, cross-linking can be performed appropriately. Also, if the cross-linking time is 50 minutes or less, cross-linking can be performed appropriately.

Molded bodies manufactured by this method have excellent resistance to flex cracking, and can be used in various applications such as wire coating materials, motor pump stator materials, industrial rubber rollers, automotive dust boots, and automotive hoses. is.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.
Various physical properties of molded articles (sheets) prepared in Examples and Comparative Examples were evaluated by the following methods.

[Mooney viscosity]
For the unvulcanized composition, using a Mooney viscometer (SMV-300RT manufactured by Shimadzu Corporation) as a measuring device, using an L rotor in the method specified in JIS K6300-2: 2001, 121 ° C. The Mooney viscosity ML ₁₊₄ (121° C.) was measured (after 1 minute of preheating and 4 minutes of rotation).

[Crystal amount]
Using a DSC (DSC7020 manufactured by Hitachi High-Tech Science Co., Ltd.), the measurement was performed according to the method specified in JIS K7122:2012. The term “amorphous” as used herein means that the heat of crystal fusion measured by heating a measurement sample from room temperature at a rate of 10° C. per minute using a differential scanning calorimeter is 2.0 J/g or less. means

[hardness]
It was carried out by the method (type A) specified in JIS K6253-3:2012. The durometer was measured using an Asker rubber durometer type A manufactured by Kobunshi Keiki Co., Ltd.

[Elongation and tensile strength]
Using a Shopper-type tensile tester Model 5 manufactured by Ueshima Seisakusho Co., Ltd., the test was performed according to the method specified in JIS K6251:2005. The test piece was measured with a No. 3 dumbbell, a distance between chucks of 20 mm, a tensile speed of 500 mm/min, and a measurement temperature of 23°C.

[Flexion crack growth]
The flex crack initiation test (flex crack growth) was performed by a method specified in JIS K6260: 2017 using a 20-hang flex tester and constant elongation fatigue tester with a special constant temperature bath manufactured by Ueshima Seisakusho Co., Ltd.

[Taber wear]
Using a Taber abrasion tester manufactured by Toyo Seiki Seisakusho Co., Ltd., it was carried out according to the method specified in JIS K6264-2:2005. A H22 grindstone was used, and the wear volume (cm ³ ) was measured under a load of 9.8N and 1000 times of testing.

Examples 1-11, Comparative Examples 1-5:
The ingredients used in Examples 1 to 11 and Comparative Examples 1 to 5 are as follows.
(A) Chlorinated polyolefin (A) 75% by mass of chlorinated polyethylene having a chlorine content of 32% by mass (Elaslen (registered trademark) 301MA manufactured by Showa Denko) obtained by chlorinating high-density polyethylene as the component (A), and high-density polyethylene A mixture of 25% by mass of chlorinated polyethylene having a chlorinated chlorine content of 32% by mass (Elaslen (registered trademark) 303A manufactured by Showa Denko) was used. All chlorinations were carried out by an aqueous suspension method.
(1) Eraslen (registered trademark) 301MA manufactured by Showa Denko K.K.
(2) Eraslen (registered trademark) 303A manufactured by Showa Denko K.K. (chlorine content: 32% by mass, amount of crystals (heat of crystal melting): 2 J/g or less).

(B) Cyclohexene carboxylic acid ester
(1) Bis(2-ethylhexyl) 4-cyclohexene-1,2-dicarboxylate (Cysocizer (registered trademark) DOTH, manufactured by Shin Nippon Rika Co., Ltd.).

(C) a plasticizer
(1) Mesamoll (registered trademark) (manufactured by Lanxess Corporation, alkylsulfonic acid phenyl ester),
(2) 1,2-benzenedicarboxylic acid-1,2-isodecyl ester (Sanso Cizer (registered trademark) DIDP, manufactured by Shin Nippon Rika Co., Ltd.),
(3) bis(2-ethylhexyl) 1,4-benzenedicarboxylate (D-810, manufactured by ADEKA Corporation),
(4) 7-oxabicyclo[4.1.0]heptane-3,4-dicarboxylic acid di(2-ethylhexyl) (Cysocizer (registered trademark) E-PS, manufactured by Shin Nippon Rika Co., Ltd.),
(5) tri-2-ethylhexyl trimellitate (TOTM);

(D) curing agent
(1) Diallyl phthalate (DAP, manufactured by Osaka Soda Co., Ltd.)
(2) Diallyl 1,2-cyclohexanedicarboxylate (DAC, manufactured by Osaka Soda Co., Ltd.)
(3) triallyl isocyanurate (TAIC (registered trademark), manufactured by Nippon Kasei Co., Ltd.).

(E) an acid acceptor
(1) Synthetic hydrotalcite (DHT-4A (registered trademark), manufactured by Kyowa Chemical Industry Co., Ltd.)

(F) organic peroxide
(1) Perhexyne (registered trademark) 25B-40: 2,5-bis(t-butylperoxy)-2,5-dimethyl-3-hexyne manufactured by NOF Corporation, purity 40%
(2) Perhexa (registered trademark) 25B: 2,5-di(t-butylperoxy)-2,5-dimethyl-hexane manufactured by NOF Corporation with a purity of 90% or more

(G) Reinforcing material Carbon black (manufactured by Cabot Japan Co., Ltd., Show Black (registered trademark) N330

Each component other than (F) was kneaded for 2.5 minutes at 60 rpm in a Banbury (registered trademark) mixer at the compounding amounts (parts by mass) shown in Table 1.
The resulting kneaded product was wound around two open rolls, and (F) was added, uniformly dispersed, and taken out in the form of a sheet.
The obtained sheet was placed in a mold and compression molded at 160° C. for 30 minutes to prepare an evaluation sheet having a thickness of 2 mm. The molds used were those specified in JIS K-6299:2012 for samples for elongation and tensile strength, and those specified in JIS K-6260:2017 for flex crack growth.
The properties of each sheet thus obtained were evaluated, and the results are shown in Table 1 at the bottom.

From Examples 1 to 11, the composition of the present invention has a good flex crack generation frequency and an excellent elongation rate. In Comparative Examples 1 to 5, in which bis(2-ethylhexyl) 4-cyclohexene-1,2-dicarboxylate (DOTH) was not added and other plasticizers were added, the number of times flex cracks occurred and the elongation rate were low.
Therefore, it can be seen that the composition containing DOTH has a good flex crack generation frequency and an excellent elongation rate, and can achieve the object of the present invention.

Claims (13)

Chlorinated polyolefin (A), cyclohexene carboxylic acid ester (B) and organic peroxide (F) ,
The cyclohexenecarboxylic acid ester (B) is 4-cyclohexene-1,2-dicarboxylic acid bis(2-ethylhexyl),
A chlorinated polyolefin composition. 2. The chlorinated polyolefin composition according to claim 1, wherein said chlorinated polyolefin (A) is chlorinated polyethylene. 3. The chlorinated polyolefin composition according to claim 1 or 2 , comprising 5 to 50 parts by mass of the cyclohexenecarboxylic acid ester (B) with respect to 100 parts by mass of the chlorinated polyolefin (A). The chlorine according to any one of claims 1 to 3 , which contains 0.4 parts by mass or more and 8.0 parts by mass or less of the organic peroxide (F) with respect to the chlorinated polyolefin (A) in terms of 100% purity. polyolefin composition. 5. The chlorinated polyolefin composition according to any one of claims 1 to 4 , further comprising a curing agent (D). 6. The chlorinated polyolefin composition according to claim 5 , wherein the curing agent (D) is diallyl 1,2-benzenedicarboxylate or bis(2-propenyl) 1,2-cyclohexanedicarboxylate. 7. The chlorinated polyolefin composition according to any one of claims 1 to 6 , further comprising an acid acceptor (E). 8. The chlorinated polyolefin composition according to claim 7 , wherein the acid acceptor (E) is hydrotalcite, an oxide of a Group II metal of the periodic table or a hydroxide of a Group II metal of the periodic table. The organic peroxide (F) is 2,5-bis(t-butylperoxy)-2,5-dimethyl-3-hexyne or 2,5-di(t-butylperoxy)-2,5-dimethyl- The chlorinated polyolefin composition according to any one of claims 1 to 8 , which is hexane. 10. The chlorinated polyolefin composition according to any one of claims 1 to 9 , further comprising a reinforcing material (G). 11. The chlorinated polyolefin composition according to claim 10 , wherein said reinforcing material (G) is carbon black or silica. A molded article obtained by molding and crosslinking the chlorinated polyolefin composition according to any one of claims 1 to 11 . A method for producing a molded article, which comprises molding and crosslinking the chlorinated polyolefin composition according to any one of claims 1 to 11 .