JP5010448B2 - Polyolefin resin molded body and method for producing the same - Google Patents

Description

  The present invention relates to a polyolefin resin molded article obtained by heating, kneading and molding a polyolefin resin composition, and more specifically, a polyolefin resin molded article having improved long-term mechanical properties and production thereof. Regarding the method.

  Polyolefin resins are relatively inexpensive and have good moldability, heat resistance, solvent resistance, mechanical properties, appearance, and the like, and thus are processed into various molded products and used in many fields. In addition, since polyolefin resins are also excellent in earthquake resistance, their use in pipe fields such as gas pipes and water pipes has been increasing in recent years.

  Polyolefin resin used for gas pipes, water pipes, and the like needs to satisfy excellent long-term mechanical properties such as PE80 (MRS: Minimum Required Strength = 8 MPa) and PE100 (MRS = 10 MPa) defined by ISO 9080 and ISO 12162. There is.

The polyolefin resin is produced by copolymerizing ethylene and α-olefin by multistage polymerization in the presence of an appropriate polymerization catalyst. Polyolefin resin polymerization techniques are described in many documents including Patent Document 1 below. Since the polymerization technology of polyolefin resin has already been sufficiently matured technically, it has been very difficult to improve the long-term mechanical properties of polyolefin resin more than the present by the polymerization technology of polyolefin resin.
JP-A-8-301933

  An object of the present invention is to provide a polyolefin resin molded article having improved long-term mechanical properties and a method for producing the polyolefin resin molded article without depending on the polymerization technology of the polyolefin resin in view of the current state of the prior art described above. It is to provide.

  According to the present invention, a polyolefin resin molded product obtained by heating, kneading and molding a polyolefin resin composition, wherein the polyolefin resin composition comprises a polyolefin thermoplastic resin and 1 minute. A polyolefin-based resin molded article comprising an organic peroxide having a half-life temperature in the range of 140 to 220 ° C. and a layered silicate treated with an organic compound having an unsaturated double bond. Provided.

  In a specific aspect of the present invention, the organic compound having an unsaturated double bond is a vinylsilane compound represented by the following formula (1).

_{CH 2 = CH-SiR n X} 3-n (1)
In the above formula (1), R represents hydrogen or an alkyl group having 3 or less carbon atoms, X represents an alkoxy group having 3 or less carbon atoms, and n represents an integer of 0 to 2. When n is 2, a plurality of R may be the same or different. When n is 0 or 1, a plurality of X may be the same or different.

  In another specific aspect of the present invention, the vinylsilane compound is trimethoxyvinylsilane and / or triethoxyvinylsilane.

In the polyolefin resin molded body according to the present invention , the layered silicate treated with the organic compound having an unsaturated double bond includes a suspension (A) obtained by dispersing the layered silicate in water and It is a layered silicate obtained by stirring and mixing an organic compound having an unsaturated double bond or its aqueous solution (B) to obtain a mixed solution, and then drying a precipitate separated from the mixed solution. .

  In another specific aspect of the present invention, an organic cation is present between the layers of the layered silicate.

  In still another specific aspect of the present invention, the polyolefin-based thermoplastic resin is polyethylene.

Further, according to the present invention, there is provided a method for producing a polyolefin resin molded body according to the present invention, wherein the polyolefin resin composition is kneaded at a temperature not lower than the melting point of the polyolefin thermoplastic resin and not higher than the melting point + 150 ° C. A step of decomposing the organic peroxide and dispersing the layered silicate, and a step of molding the polyolefin resin composition in which the organic peroxide is decomposed and the layered silicate is dispersed. wherein the layered silicate is characterized Oh Rukoto water swellable mica, producing a polyolefin resin molded article is provided. In the method for producing a polyolefin-based resin molded body according to the present invention, the layered silicate treated with the organic compound having an unsaturated double bond is a suspension obtained by dispersing the layered silicate in water ( A) and an organic compound having an unsaturated double bond or an aqueous solution thereof (B) are mixed by stirring to obtain a mixed solution, and then the precipitated silicic acid produced from the mixed solution is dried to obtain a layered silicic acid. Salt.

  The polyolefin resin molded body according to the present invention is obtained by heating and kneading and molding a polyolefin resin composition containing a polyolefin thermoplastic resin, the specific organic peroxide, and the specific layered silicate. Therefore, it has excellent long-term mechanical properties.

  According to the method for producing a polyolefin resin molded body according to the present invention, the polyolefin resin composition is kneaded at the specific temperature, the organic peroxide is decomposed and the layered silicate is dispersed, and then the polyolefin resin is dispersed. Since the resin composition is molded, it is possible to provide a polyolefin resin molded article having excellent long-term mechanical properties. Moreover, in this invention, the long-term mechanical physical property of the molded object containing a polyolefin-type thermoplastic resin can be improved effectively, without resorting to the polymerization technique of polyolefin-type resin.

  Details of the present invention will be described below.

  The polyolefin resin molding according to the present invention is a molding containing a polyolefin resin obtained by heating, kneading and molding a polyolefin resin composition.

  The polyolefin resin composition is treated with a polyolefin thermoplastic resin, an organic peroxide having a one-minute half-life temperature in the range of 140 ° C. to 220 ° C., and an organic compound having an unsaturated double bond. And lamellar silicate.

(Polyolefin thermoplastic resin)
Although it does not specifically limit as said polyolefin-type thermoplastic resin contained in the said polyolefin-type resin composition, For example, a low density polyethylene, a linear low density polyethylene, a medium density polyethylene, a high density polyethylene, an ethylene-alpha olefin copolymer , Propylene-α olefin copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, polypropylene and the like. These may be used alone or in combination of two or more.

  Among these, high-density polyethylene or medium-density polyethylene is preferable because long-term mechanical properties are further improved. In addition, since long-term mechanical properties are further enhanced, high-density polyethylene or medium-density polyethylene is obtained by copolymerizing ethylene and α-olefin by multistage polymerization in the presence of an appropriate polymerization catalyst. Is preferred.

(Organic peroxide)
The organic peroxide contained in the polyolefin resin composition has a one-minute half-life temperature in the range of 140 to 220 ° C. The 1-minute half-life temperature indicates a decomposition temperature at which the half-life of the organic peroxide is 1 minute.

  The organic peroxide is blended in an amount of preferably 0.01 to 3.0 parts by weight, more preferably 0.03 to 2.0 parts by weight with respect to 100 parts by weight of the polyolefin-based thermoplastic resin. If the amount of the organic peroxide is too small, the dispersibility of the layered silicate may not be sufficiently improved. If the amount is too large, crosslinking of the polyolefin-based thermoplastic resin may proceed.

  The organic peroxide having a one-minute half-life temperature in the range of 140 to 220 ° C. is not particularly limited, but includes diacyl peroxide compounds, dialkyl peroxide compounds, peroxyketal compounds, alkyl perester compounds, percarbonate compounds, and the like. Is mentioned. Specifically, 1,1-di (t-butylperoxy) -2-methylcyclohexane, 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (T-hexylperoxy) cyclohexane, 1,1-di (t-butylperoxy) cyclohexane, 2,2-di (4,4-di- (t-butylperoxy) cyclohexyl) propane, t-hexylper Oxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyisopropylmonocarbonate, t-butyl Peroxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2 5-di (benzoylperoxy) hexane, t-butylperoxyacetate, 2,2-di (t-butylperoxy) butane, t-butylperoxycybenzoate, n-butyl-4,4-di (t -Butylperoxy) valerate, di- (2-t-butylperoxyisopropyl) benzene, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxide) Oxy) hexane, di-t-butyl peroxide, t-butylcumyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 and the like It is done. These organic peroxides may be used alone or in combination of two or more.

  As said organic peroxide, a dialkyl peroxide compound, a diacyl peroxide compound, a carbonate compound or an alkyl perester compound is preferable, a dialkyl peroxide compound or a carbonate compound is more preferable, and a dialkyl peroxide compound is more preferable.

(Layered silicate)
The layered silicate contained in the polyolefin resin composition is treated with an organic compound having an unsaturated double bond.

  Examples of the layered silicate include smectite clay minerals such as montmorillonite, hectorite, saponite, beidellite, stevensite and nontronite, water-swellable mica, vermiculite, and halloysite. These may be natural or synthesized. Among these, montmorillonite and / or water-swellable mica is preferable and water-swellable mica is more preferable because it is efficiently treated with an organic compound having an unsaturated double bond. These layered silicates may be used alone or in combination of two or more.

  The crystal form of the layered silicate is not particularly limited. The average length of the layered silicate is preferably 0.01 to 3 μm, and more preferably 0.05 to 2 μm. The thickness of the layered silicate is preferably 0.001 to 1 μm, and more preferably 0.01 to 0.5 μm. The aspect ratio of the layered silicate is preferably 20 to 500, more preferably 50 to 200.

  The layered silicate is preferably blended at a ratio of 0.1 to 100 parts by weight, more preferably 0.3 to 20 parts by weight, with respect to 100 parts by weight of the polyolefin-based thermoplastic resin. If the amount of layered silicate is too small, the physical properties such as creep strength may not be sufficiently improved. If too much, it is necessary to add a large amount of organic peroxide to disperse. In this case, the polyolefin-based thermoplastic resin Crosslinking may proceed.

  Exchangeable metal cations are present between the layered silicate layers. The exchangeable metal cation means a metal ion such as sodium or calcium existing on the surface of the lamellar crystal of the layered silicate. Since these metal ions have cation exchange with a cationic substance, various cationic substances such as organic cations can be inserted (intercalated) between the crystal layers of the layered silicate.

  Although it does not specifically limit as a cation exchange capacity | capacitance of the said layered silicate, It is 50-200 milliequivalent / 100g. When the cation exchange capacity is less than 50 milliequivalents / 100 g, the amount of the cationic substance intercalated between the crystal layers of the layered silicate by cation exchange is reduced, so that the crystal layers are sufficiently depolarized ( May not be hydrophobized). When the cation exchange capacity exceeds 200 milliequivalents / 100 g, the bonding force between the crystal layers of the layered silicate becomes too strong, and the crystal flakes may be difficult to peel off.

  Organic cations may be present between the layered silicate layers. In order to allow organic cations to exist between the layers of the layered silicate, the layered silicate may be chemically treated. However, the molecular weight of the organic cation is smaller than the molecular weight of the polyolefin-based thermoplastic resin. For this reason, depending on the type of organic cation, the long-term mechanical properties of the molded product may be lowered, so care must be taken in selecting the organic cation.

  The chemical treatment can be performed, for example, by a chemical modification method called a cation exchange method. Specifically, it is a method of exchanging cations between layered silicate layers with an organic cation such as a cationic surfactant.

  The cationic surfactant is not particularly limited, and examples thereof include quaternary ammonium salts and quaternary phosphonium salts. Of these, alkyl ammonium ions, aromatic quaternary ammonium ions, or heterocyclic quaternary ammonium ions having 6 or more carbon atoms are preferred because the crystal layers of the layered silicate can be sufficiently hydrophobized.

  The quaternary ammonium salt is not particularly limited. For example, trimethylalkylammonium salt, triethylalkylammonium salt, tributylalkylammonium salt, dimethyldialkylammonium salt, dibutyldialkylammonium salt, methylbenzyldialkylammonium salt, dibenzyldialkylammonium salt. , Trialkylmethylammonium salt, trialkylethylammonium salt, trialkylbutylammonium salt; benzylmethyl {2- [2- (p-1,1,3,3-tetramethylbutylphenoxy) ethoxy] ethyl} ammonium chloride A quaternary ammonium salt having an aromatic ring such as: a quaternary ammonium salt derived from an aromatic amine such as trimethylphenylammonium; an alkylpyridinium salt, an imidazoli A quaternary ammonium salt having a heterocyclic ring such as a dimethyl salt; a dialkyl quaternary ammonium salt having two polyethylene glycol chains, a dialkyl quaternary ammonium salt having two polypropylene glycol chains, and a trialkyl quaternary having one polyethylene glycol chain Examples include ammonium salts and trialkyl quaternary ammonium salts having one polypropylene glycol chain. Among them, lauryl trimethyl ammonium salt, stearyl trimethyl ammonium salt, trioctyl methyl ammonium salt, distearyl dimethyl ammonium salt, di-cured tallow dimethyl ammonium salt, distearyl dibenzyl ammonium salt, N-polyoxyethylene-N-lauryl-N N-dimethylammonium salt and the like are preferable. These quaternary ammonium salts may be used alone or in combination of two or more.

  The quaternary phosphonium salt is not particularly limited. For example, dodecyltriphenylphosphonium salt, methyltriphenylphosphonium salt, lauryltrimethylphosphonium salt, stearyltrimethylphosphonium salt, trioctylmethylphosphonium salt, distearyldimethylphosphonium salt, distearyl And dibenzylphosphonium salts. These quaternary phosphonium salts may be used alone or in combination of two or more.

  The layered silicate is treated with an organic compound having an unsaturated double bond. The organic compound having an unsaturated double bond may be bonded to the interlayer portion of the layered silicate or may be bonded to the end face. The layered silicate may be a laminate in which a plurality of layers are laminated, and an organic compound having an unsaturated double bond may be bonded to the surface layer of the laminate. An organic compound having an unsaturated double bond may be mixed with the layered silicate.

  Although it does not specifically limit as an organic compound which has the said unsaturated double bond, A vinylsilane compound, unsaturated fatty acid, vinyl chloride, acrylic ester, styrene, vinyl acetate, etc. are mentioned. Among these, vinylsilane compounds that can be easily bonded to the layered silicate by silanol condensation are preferable.

  As the vinyl silane compound, a vinyl silane compound represented by the following formula (1) is preferable. Since the vinylsilane compound is efficiently bonded to the layered silicate, the layered silicate to which the vinylsilane compound is bonded can be obtained more easily.

_{CH 2 = CH-SiR n X} 3-n (1)
In the above formula (1), R represents hydrogen or an alkyl group having 3 or less carbon atoms, X represents an alkoxy group having 3 or less carbon atoms, and n represents an integer of 0 to 2. When n is 2, a plurality of R may be the same or different. When n is 0 or 1, a plurality of X may be the same or different.

  Specific examples of the vinyl silane compound include trimethoxy vinyl silane, triethoxy vinyl silane, tripropoxy vinyl silane, triisopropoxy vinyl silane, dimethoxy vinyl silane, diethoxy vinyl silane, dimethoxy methyl vinyl silane, diethoxy ethyl vinyl silane, ethyl dimethoxy vinyl silane, diethoxy methyl vinyl silane. , Methoxyvinylsilane, ethoxyvinylsilane, methoxydimethylvinylsilane, ethoxydiethylvinylsilane, diethylmethoxyvinylsilane, ethoxydimethylvinylsilane, and the like. Among these, trimethoxyvinylsilane and / or triethoxyvinylsilane are preferable because a layered silicate to which a vinylsilane compound is bonded can be more easily obtained.

  The method for obtaining the layered silicate treated with the organic compound having an unsaturated double bond is not particularly limited. For example, the layered silicate in a powder state or the like is used as a stock solution of an organic compound having an unsaturated double bond or A method in which a diluted solution is added directly; obtained by sedimentation separation, centrifugation, etc. from a stock solution of an organic compound having an unsaturated double bond or a mixed solution obtained by adding a diluted solution to a suspension in which layered silicate is dispersed in water. A method of purifying, drying, and crushing the obtained material; a cationic surfactant in a mixed solution obtained by adding a stock solution or diluted solution of an organic compound having an unsaturated double bond to a suspension obtained by dispersing a layered silicate in water Etc., and the resulting precipitate is purified, dried, and pulverized; from a mixture of a layered silicate dispersed in water with a cationic surfactant added by sedimentation, centrifugation, etc. Tired of the resulting material A method in which purified, dried and ground to those obtained by adding a stock solution or a dilute solution of an organic compound having a double bond.

  As the layered silicate treated with the organic compound having an unsaturated double bond, the suspension (A) obtained by dispersing the layered silicate in water and the organic compound having an unsaturated double bond Alternatively, a solution obtained by stirring and mixing the aqueous solution (B) to obtain a mixed solution, and then drying a precipitate separated from the mixed solution is preferable.

  The method for preparing the suspension (A) is not particularly limited. Preferably, the suspension (A) is prepared by blending 0.1 to 10.0 parts by weight of layered silicate with 100 parts by weight of water. It is obtained by dispersing layered silicate in water. When the layered silicate is dispersed in water, the layered silicate swells and the interlayer distance of the layered silicate increases. As the water, ion exchange water, pure water, ground water, tap water, industrial water, or the like is used.

  The organic compound having the unsaturated double bond or the aqueous solution (B) thereof is not particularly limited. When the organic compound having an unsaturated double bond or the aqueous solution (B) thereof is an aqueous solution, the aqueous solution is 0.1 to 10.0 weight by weight of an organic compound having an unsaturated double bond in 100 parts by weight of water. An aqueous solution obtained by blending parts and dissolving the organic compound in water is preferred.

  When trimethoxyvinylsilane is used as the organic compound having an unsaturated double bond, it is not necessary to adjust the pH of the aqueous solution (B). On the other hand, when triethoxyvinylsilane is used as the organic compound having an unsaturated double bond, the aqueous solution (B) preferably has a pH adjusted to 2-6. When the pH of the aqueous solution (B) is 2 to 6, the solubility of the vinylsilane compound in water is further enhanced, and the organic compound having an unsaturated double bond is more efficiently bound to the layered silicate. be able to. In particular, when the layered silicate is water-swellable mica or smectite, an organic compound having an unsaturated double bond can be bound to the layered silicate even more efficiently.

  In order to adjust the pH of the aqueous solution (B) to 2 to 6, for example, an acid may be added in advance to water containing an organic compound having an unsaturated double bond. Examples of the acid include organic acids such as oxalic acid, formic acid, maleic acid, fumaric acid, and acetic acid, and inorganic acids such as hydrochloric acid, phosphoric acid, nitric acid, boric acid, sulfuric acid, and hydrofluoric acid.

  The suspension (A) and the organic compound having an unsaturated double bond or an aqueous solution (B) thereof are mixed with stirring. The stirring time is preferably 0.1 to 100 hours. The stirring and mixing may be performed at room temperature (23 ° C.) or may be performed by heating to 60 to 90 ° C., for example, in order to promote the progress of the reaction.

  Layered silicic acid treated with an organic compound having an unsaturated double bond by drying a mixture of the suspension (A) and the organic compound having an unsaturated double bond or an aqueous solution thereof (B) A salt is obtained. In addition, when a sedimentation product is generated in the mixed solution by allowing the mixed solution to stand, the sedimentation product can be easily recovered by, for example, a centrifugal separation process. Although it does not specifically limit as drying conditions of a sedimentation separated material, It is preferable to dry a sedimentation separated material at 10-80 degreeC for 1 to 100 hours.

(Manufacturing method of polyolefin resin molding)
The polyolefin resin composition is obtained by blending the polyolefin thermoplastic resin, the specific organic peroxide, and the specific layered silicate.

  The polyolefin resin molded body according to the present invention can be obtained by heating, kneading and molding the above polyolefin resin composition. For example, the polyolefin resin molded body can be obtained by heating and kneading a polyolefin resin composition, cooling and molding.

  In the production of a polyolefin resin molded product, the polyolefin resin composition is kneaded at a temperature not lower than the melting point of the polyolefin thermoplastic resin and not higher than the melting point + 150 ° C. to decompose the organic peroxide and disperse the layered silicate. It is preferable to make it. Thereby, the said layered silicate can be combined with polyolefin resin. If the kneading temperature is lower than the melting point of the polyolefin-based thermoplastic resin, the polyolefin-based thermoplastic resin does not melt and the moldability may be impaired. If the kneading temperature exceeds 150 ° C, the polyolefin-based thermoplastic resin is decomposed or discolored. Sometimes. The melting point of the polyolefin-based thermoplastic resin indicates the temperature at the peak of the heat of absorption curve measured by differential scanning calorimetry (DSC).

  After kneading at the above temperature, the polyolefin resin composition in which the organic peroxide is decomposed and the layered silicate is dispersed is molded.

  Examples of the molding method of the polyolefin resin composition in which the organic peroxide is decomposed and the layered silicate is dispersed include extrusion molding, injection molding, and press molding.

  In JP-A-2005-113008, (C) organic peroxide is used to graft (B) a compound having an amino group and an unsaturated bond onto (A) a polyolefin resin. (C) The organic peroxide is decomposed when (A) the polyolefin resin is modified to obtain a modified polyolefin resin. Therefore, (C) the organic peroxide is decomposed when the layered silicate is dispersed, and the (C) organic peroxide is not used for bonding the layered silicate to the polyolefin. Even if the layered silicate was dispersed in such a modified olefin resin, long-term mechanical properties could not be improved.

  On the other hand, in the method for producing a polyolefin resin molded body according to the present invention, the polyolefin resin composition containing the polyolefin thermoplastic resin, the specific organic peroxide and the specific layered silicate is specified. Kneading at a temperature of 1 to decompose the organic peroxide and disperse the layered silicate, so that the dispersibility of the layered silicate in the polyolefin-based thermoplastic resin is enhanced and the layered silicate is bonded to the polyolefin-based thermoplastic resin. Can be made. Further, in the present invention, it is possible to improve the long-term mechanical properties of a polyolefin-based thermoplastic resin molded article by simply heating, kneading and molding the polyolefin-based resin composition without depending on the polymerization technology of the polyolefin resin. it can.

  EXAMPLES Hereinafter, although an Example is hung up and this invention is demonstrated in more detail, this invention is not limited only to these Examples.

Example 1
To 100 parts by weight of ion-exchanged water, 3.0 parts by weight of water-swellable mica ME100 (manufactured by Corp Chemical) was added and stirred for 1 hour to obtain a suspension in which mica was dispersed in water. To the obtained suspension, 0.3 part by weight of trimethoxyvinylsilane S210 (manufactured by Chisso Corporation) was added dropwise and stirred for 2 hours to obtain a mixed solution. The resulting mixture was centrifuged to collect a precipitate separation. The recovered precipitate isolate is dried in an oven at 50 ° C. and further dried in a vacuum dryer at 50 ° C. to completely remove moisture from the precipitate isolate, and silane-treated mica treated with trimethoxyvinylsilane is removed. Obtained.

  100 parts by weight of high-density polyethylene (melting point: 132 ° C.) as a polyolefin-based thermoplastic resin and 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 (Nippon Yushi) as an organic peroxide Perhexine 25B, 1 minute half-life temperature 194.3 ° C) 0.2 parts by weight and 5.0 parts by weight of the above silane-treated mica as a layered silicate were blended to obtain a polyolefin resin composition. .

  Next, using a Laboplast mill (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the obtained polyolefin resin composition is kneaded at 160 ° C. for 5 minutes to decompose the organic peroxide and disperse the layered silicate. A resin material was obtained. Using a press molding machine adjusted to 200 ° C., the polyolefin resin material obtained was pressed together with a spacer having a thickness of 4 mm at a pressure of 4.9 MPa for 3 minutes to obtain a polyolefin resin molded body having a thickness of 4 mm. Obtained.

(Example 2)
In Example 1, a polyolefin resin molded article was obtained in the same manner as in Example 1 except that triethoxyvinylsilane S220 (manufactured by Chisso Corporation) was used instead of trimethoxyvinylsilane S210.

(Example 3)
A polyolefin-based resin molded body was obtained in the same manner as in Example 1 except that montmorillonite Cloisite Na (manufactured by Southern Clay Products) was used as the layered silicate instead of water-swellable mica ME100.

Example 4
A polyolefin-based resin molded body was obtained in the same manner as in Example 1 except that smectite SWN (manufactured by Co-op Chemical) was used as the layered silicate instead of water-swellable mica ME100.

(Example 5)
A polyolefin resin molded article was obtained in the same manner as in Example 1 except that the dropping amount of vinyltrimethoxysilane was 2.0 parts by weight.

( Reference Example 6) In Reference Examples 1 to 5, 100 parts by weight of powdery water-swellable mica ME100 (manufactured by Coop Chemical Co.) is added to a crusher which is a missing number, and trimethoxyvinylsilane S210 (manufactured by Chisso Corp.) Ten parts by weight were added dropwise. Thereafter, crushing was performed for 1 hour to obtain a polyolefin-based resin molded body in the same manner as in Example 1 except that silane-treated mica was used.

( Reference Example 7)
A polyolefin resin molded article was obtained in the same manner as in Reference Example 6 except that montmorillonite Cloisite Na (manufactured by Southern Clay Products) was used as the layered silicate instead of water-swellable mica ME100.

(Comparative Example 1)
A polyolefin resin molded article was obtained in the same manner as in Example 1 except that no organic peroxide was blended and no silane-treated mica was blended.

(Comparative Example 2)
A polyolefin resin molded article was obtained in the same manner as in Example 1 except that silane-treated mica was not blended.

(Comparative Example 3)
A polyolefin resin molded article was obtained in the same manner as in Example 1 except that no organic peroxide was added.

(Comparative Example 4)
A polyolefin-based resin molded body was obtained in the same manner as in Example 1 except that water-swellable mica ME100 was used instead of silane-treated mica.

(Evaluation)
(1) Creep test with all notches According to ISO DIS 16770, long-term mechanical properties were evaluated by a full notch creep test (FNCT). As a sample, a specimen having a cross section of 4 mm × 11 mm and notched with a razor blade was prepared. A tensile stress corresponding to 11 MPa was applied to the specimen in water at 60 ° C., and the time until the specimen broke was measured.

(2) Amount of vinylsilane compound contained in layered silicate treated with vinylsilane compound (silane-treated layered silicate) Absorption spectrum of silane-treated layered silicate obtained in Examples 1, 2, 5 and Reference Example 6 Was measured using a Fourier transform infrared spectroscopic analyzer (FT-IR). The ratio (absorbance ratio) of the absorbance at a wavelength of 1,410 cm ⁻¹ corresponding to the absorption of a vinyl group (C═C) to the absorbance at a wavelength of 970 cm ⁻¹ corresponding to the absorption of layered silicate (Si—O) was measured.

In addition, the layered silicate and vinylsilane compound used when treating the layered silicate with the vinylsilane compound in Examples 1, 2, 5 and Reference Example 6 were mixed at a predetermined mixing ratio at room temperature. A similar FT-IR measurement was performed to obtain a calibration curve.

From the obtained measured values, the amount of vinylsilane in 100% by weight of the silane-treated layered silicate obtained in Examples 1, 2, 5 and Reference Example 6 was determined.

  The results are shown in Table 1 below.

Claims (5)

A polyolefin resin molded article obtained by heating and kneading a polyolefin resin composition and molding,
The polyolefin resin composition is treated with a polyolefin thermoplastic resin, an organic peroxide having a one-minute half-life temperature in the range of 140 to 220 ° C., and a layered structure treated with an organic compound having an unsaturated double bond only contains a silicate,
The layered silicate treated with the organic compound having an unsaturated double bond includes a suspension (A) obtained by dispersing the layered silicate in water, an organic compound having an unsaturated double bond, or A polyolefin-based resin molded article, which is a layered silicate obtained by stirring and mixing the aqueous solution (B) to obtain a mixed solution, and then drying a precipitate separated from the mixed solution. . The polyolefin resin molded product according to claim 1, wherein the organic compound having an unsaturated double bond is a vinylsilane compound represented by the following formula (1).
_{CH 2 = CH-SiR n X} 3-n (1)
In the above formula (1), R represents hydrogen or an alkyl group having 3 or less carbon atoms, X represents an alkoxy group having 3 or less carbon atoms, and n represents an integer of 0 to 2. When n is 2, a plurality of R may be the same or different. When n is 0 or 1, a plurality of X may be the same or different.   The polyolefin resin molded product according to claim 2, wherein the vinylsilane compound is trimethoxyvinylsilane and / or triethoxyvinylsilane. The polyolefin resin molded product according to any one of claims 1 to 3 , wherein the polyolefin-based thermoplastic resin is polyethylene. A method for producing a polyolefin-based resin molded article according to any one of claims 1 to 4 ,
Polyolefin resin comprising a polyolefin thermoplastic resin, an organic peroxide having a 1 minute half-life temperature in the range of 140 to 220 ° C., and a layered silicate treated with an organic compound having an unsaturated double bond The layered silicate, which is a composition and is treated with the organic compound having an unsaturated double bond, comprises a suspension (A) obtained by dispersing the layered silicate in water, an unsaturated double bond, and A polyolefin-based resin composition which is a layered silicate obtained by stirring and mixing an organic compound having a bond or an aqueous solution thereof (B) to obtain a mixed solution and then drying a precipitate separated from the mixed solution. Using,
Kneading the polyolefin resin composition at a temperature not lower than the melting point of the polyolefin thermoplastic resin and not higher than the melting point + 150 ° C., decomposing the organic peroxide and dispersing the layered silicate;
Forming the polyolefin resin composition in which the organic peroxide is decomposed and the layered silicate is dispersed , and
The layered silicate is characterized Oh Rukoto water swellable mica, producing a polyolefin resin molded article.