JP2006193606A - Propylene-based polymer composition for sheet molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a propylene-based polymer composition capable of producing propylene-based polymer sheet of high rigidity and transparency and good moldability, to provide such propylene-based polymer sheet obtained from the polymer composition, to provide a method for producing the propylene-based polymer sheet, and to provide a secondary-processed molded form of the propylene-based polymer sheet. <P>SOLUTION: The propylene-based polymer composition for sheet molding comprises 5-60 wt.% of the component A mentioned below and 40-95 wt.% of the component B mentioned below. The component A is a propylene polymer having an MFR of 0.1-20 g/10min, a density of 0.905 g/cm<SP>3</SP>or higher and a Q-value of 7 or greater. The component B is a propylene-α-olefin copolymer having an MFR of 0.1-20 g/10min and a melting temperature(Tm) of 110-155°C and meeting the relationship(1): -7.5Cx+146≤Tm≤-7.5Cx+162(wherein Cx is the α-olefin content(wt%) of the propylene-α-olefin copolymer). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a propylene-based polymer composition for molding a sheet capable of obtaining a propylene-based polymer sheet excellent in rigidity, transparency, and thermoformability, and a propylene-based polymer obtained by the polymer composition The present invention relates to a sheet, a method for producing a propylene polymer sheet, and a secondary processed molded body of the propylene polymer sheet.

  Thermoplastic resins such as polyvinyl chloride, polystyrene resin, and polypropylene are used as various packaging materials. For processing of these packaging materials, the thermoplastic resin is extruded into a sheet shape, reheated, and vacuumed. A method of forming by secondary processing using a thermoforming method such as molding, vacuum pressure forming, etc. is adopted, and thermoforming methods such as vacuum forming are highly productive and meet a large amount of demand. In particular, it is widely used as a molding method suitable for mass production.

  On the other hand, the propylene-based polymer is excellent in heat resistance, rigidity, impact resistance, or hygiene, and is an excellent material for packaging materials such as packaging containers. There is a problem that it is inferior in transparency compared to amorphous resins such as vinyl and polystyrene resins, and because it is a crystalline resin, the elastic modulus change with respect to a change in heating temperature is large, so that it is inferior in thermoformability. There is.

  As a method for improving the transparency of the propylene polymer, a method of copolymerizing with an olefin such as ethylene or a method of adding a crystal nucleating agent is used. Although the transparency of the sheet itself can be improved to some extent, there is a problem that if the obtained sheet is subjected to secondary processing by thermoforming, the transparency is lost during that time, and the expected effect cannot be obtained.

  In recent years, thermoforming equipment has been increased in size to improve production efficiency. Propylene-based polymers are applied to such large thermoforming equipment, and a large number of sheets are taken in the width direction using wide sheets. However, since the temperature distribution is generated in the sheet and the elastic modulus becomes uneven, there is a problem that even if a good product is obtained at the central portion, devitrification occurs at the peripheral portion. Further, even in the case of molding using a narrow sheet, in the production of a molded body that requires complex design, there is a problem that it is difficult to obtain a uniform molded body due to uneven shapeability based on the temperature distribution as described above. is there.

  For this reason, when using a propylene-type polymer for thermoforming, such as vacuum forming, the extreme care for making heating temperature uniform is required. However, in order to precisely control the temperature, there is a problem that production efficiency is inevitably lowered, and it becomes impossible to meet the demand for improvement in productivity.

  For these reasons, transparency does not deteriorate due to secondary processing by thermoforming, and even when heating is non-uniform and temperature distribution occurs in the sheet, there is little effect on formability and it is difficult to apply. There is a demand for the development of a propylene-based polymer sheet capable of obtaining a molded article excellent in shape.

  As a method for solving such problems, the present applicant first uses a composition in which a propylene polymer having a specific performance and a propylene / α-olefin copolymer having a specific performance are mixed at a specific ratio. Is proposed to be effective (Patent Document 1). However, as a result of further investigations, the ethylene content of the propylene / α-olefin copolymer used in this method is considerably large as 2.3 to 2.6% by weight, and therefore its melting temperature (Tm) is 125 to 135. It was as low as about ° C. Therefore, the rigidity and thermoformability are not fully satisfactory, it is difficult to take a wide temperature range during the secondary processing, and there is an unsolved problem that should be further improved in the widening of thermoforming. It turned out to have.

In addition, it has been proposed to use only a specific low MFR (Patent Document 2), but if a low MFR is used, there is a drawback that the extrusion pressure increases and the production efficiency decreases. Furthermore, a method of adding low-density polyethylene to polypropylene and a method of adding low-density polyethylene and ethylene-propylene copolymer to polypropylene have also been proposed (Patent Documents 3 and 4), but none of them are satisfactory in transparency. A decrease in rigidity is a problem.
JP 2003-213054 A Japanese Patent Publication No. 56-15744 JP 52-136247 A JP-A-53-102950

  The present invention is excellent in rigidity and transparency, and has little influence on moldability even if temperature distribution occurs during thermoforming, and when a wide sheet is secondarily processed using a large thermoforming machine, Propylene polymer composition for sheet molding capable of producing a propylene polymer sheet capable of obtaining a molded product of uniform quality, propylene polymer sheet obtained by the polymer composition, and propylene polymer weight The present invention provides a method for producing a coalesced sheet and a secondary processed molded article of a propylene polymer sheet.

  As a result of intensive studies to achieve the above object, the present invention provides a sheet having excellent rigidity and transparency when a composition comprising Component A having specific performance and Component B having specific performance is used. When the sheet is used for vacuum forming or the like, the elastic modulus change due to the heating temperature difference is reduced, and it is found that the sheet is effective for widening the high temperature side thermoforming, and the present invention has been completed.

That is, the gist of the present invention is a sheet-forming propylene-based polymer composition comprising a polymer composition containing 5 to 60% by weight of the following component A and 40 to 95% by weight of component B. Exist.
Component A: a propylene polymer having a melt flow rate (MFR) of 0.1 to 20 g / 10 min, a density of 0.905 g / cm ³ or more, and a Q value of 7 or more,
Component B: a propylene / α-olefin copolymer satisfying the following formula (1) at a melt flow rate (MFR) of 0.1 to 20 g / 10 min, a melting temperature (Tm) of 110 to 155 ° C.,
−7.5Cx + 146 ≦ Tm ≦ −7.5Cx + 162 (1)
[However, Cx represents the α-olefin content (% by weight) of the propylene / α-olefin copolymer. ]
Another gist of the present invention resides in a propylene polymer sheet obtained by thermoforming a propylene polymer composition for sheet molding.

  Another gist of the present invention is that the propylene-based polymer composition for sheet molding is melt-extruded using a T-shaped die, and at least one side of the extruded sheet is clamped with a metal belt to be cooled and solidified. And a method for producing a propylene-based polymer sheet.

  Another gist of the present invention resides in a secondary processed molded body obtained by subjecting the propylene polymer sheet to vacuum forming or vacuum / pressure forming at a molding temperature of 130 ° C. or higher.

  The sheet obtained by thermoforming the propylene / α-olefin copolymer of the present invention is excellent in rigidity and impact resistance, has little decrease in transparency even by secondary molding, and has a temperature during secondary molding. Since the dependency is small, it is possible to obtain a secondary molded body having a uniform wall thickness and excellent shaping. The secondary compact can be easily produced by vacuum forming or vacuum / pressure forming.

  The propylene-based polymer composition for sheet molding of the present invention is mainly composed of a polymer composition comprising 5 to 60% by weight of the following component A and 40 to 95% by weight of the following component B.

Component A: Propylene polymer having MFR of 0.1 to 20 g / 10 min, density of 0.905 g / cm ³ or more, and Q value of 7 or more Component B: MFR of 0.1 to 20 g / 10 min, Tm of 110 A propylene / α-olefin copolymer satisfying the following formula (1) at ˜155 ° C.
−7.5Cx + 146 ≦ Tm ≦ −7.5Cx + 162 (1)
[However, Cx represents the α-olefin content (% by weight) of the propylene / α-olefin copolymer. ]
The propylene polymer of component A used in the present invention has a density measured by JIS-K7210 of 0.905 g / cm ³ or more, preferably 0.906 g / cm ³ or more and 0.915 or less, more preferably 0.907 g. / Cm ³ or more and 0.912 or less. If the density is less than the above range, the sheet is insufficient in rigidity, which is not preferable. The density was measured using a strand obtained in the MFR measurement described later and using a density gradient tube.

  The component A propylene polymer used in the present invention has an MFR measured in accordance with JIS-K7210 (230 ° C., 2.16 kg load) of 0.1 to 20 g / 10 minutes, preferably 0.2 to 15 g. / 10 minutes, more preferably 0.3 to 10 g / 10 minutes are used, and if the MFR exceeds the above range, the melt tension becomes insufficient and the sheet extrudability becomes poor. If the MFR is less than the above range, the sheet It becomes a flow defect at the time of molding and tends to cause a thickness fluctuation.

  The propylene polymer of component A used in the present invention has a Q value (ratio of weight average molecular weight to number average molecular weight) measured by gel permeation chromatography (GPC) of 7 or more, preferably 8 or more, and Preferably, 9 or more are used, and when the Q value is below the above range, the melt tension becomes insufficient, and the drawdown at the time of thermoforming the sheet becomes large and the thickness of the product tends to vary.

  The propylene polymer of component A used in the present invention preferably has a melting temperature (Tm) exceeding 160 ° C., more preferably exceeding 163 ° C.

  As such a propylene polymer, a propylene homopolymer and / or a random copolymer of propylene and an α-olefin having a propylene content of 99.0% by weight or more is used. As the α-olefin, ethylene, butene-1, pentene-1, hexene-1, 4-methyl-pentene-1, etc. (in the present invention, ethylene is also included in the α-olefin) can be used. Among these, a propylene homopolymer, a random copolymer of propylene and ethylene, or a blend thereof is preferable. A propylene homopolymer is particularly preferable.

  Such a propylene polymer can be obtained by using a highly stereoregular polymerization catalyst. As the highly stereoregular polymerization catalyst, a so-called titanium compound prepared by using titanium chloride, alkoxy titanium, or the like as a starting material is used. Although a Ziegler-Natta catalyst or a Kaminsky catalyst using a metallocene compound can be used, a Ziegler-Natta catalyst is desirable.

  As the polymerization mode of the propylene polymer, any method can be adopted as long as the catalyst component and the monomer come into efficient contact. Specifically, the slurry method using an inert solvent, the bulk method using propylene as a solvent substantially without using an inert solvent, the solution polymerization method, or the monomers are substantially gaseous without using a liquid solvent substantially. It is possible to employ a gas phase method that keeps the temperature constant.

  It is also applied to continuous polymerization and batch polymerization. In the case of slurry polymerization, a saturated aliphatic or aromatic hydrocarbon such as hexane, heptane, pentane, cyclohexane, benzene and toluene can be used alone or as a polymerization solvent.

  Adjustment of MFR in these polymerizations is usually performed by introducing hydrogen. In this case, the amount of hydrogen introduced may be constant from the start to the end of the polymerization, or may be changed continuously or stepwise.

  In order to obtain a polymer having a Q value of 7 or more, a catalyst that originally produces a polymer having a broad molecular weight distribution may be used, or the molecular weight of the polymer produced in each stage may be greatly changed by multistage polymerization. Such a propylene polymer can be selected from commercially available products.

  The blending ratio of the propylene polymer is 5 to 60% by weight, preferably 10 to 50% by weight, and more preferably 15 to 40% by weight with respect to the propylene-based polymer composition for sheet molding. If the blending ratio exceeds the above, thermoformability is impaired.

  The propylene / α-olefin copolymer (component B) used in the present invention has an MFR according to JIS-K7210 (230 ° C., 2.16 kg load) of 0.1 to 20 g / 10 min, preferably 0.2 to 15 g / 10 minutes, more preferably 0.3 to 10 g / 10 minutes. If the MFR exceeds the above range, the melt tension becomes insufficient and the sheet extrudability becomes poor. If the MFR is less than the above range, the flow becomes poor at the time of sheet forming, and the thickness tends to vary.

  The melting temperature (Tm) of the propylene / α-olefin copolymer used in the present invention is in the range of 135 to 160 ° C., preferably 140 to 155 ° C. Furthermore, the α-olefin content (Cx) and Tm A relationship satisfying the following formula (1) is used. More preferably, those satisfying the following formula (2), particularly preferably those satisfying the following formula (3) are used.

−7.5Cx + 146 ≦ Tm ≦ −7.5Cx + 162 (1)
−7.5Cx + 148 ≦ Tm ≦ −7.5Cx + 159 (2)
−7.5Cx + 150 ≦ Tm ≦ −7.5Cx + 156 (3)

Tm was measured by using a differential scanning calorimeter (DSC), taking a sample amount of 5.0 mg, holding it at 200 ° C. for 5 minutes, and then crystallizing it to 40 ° C. at a temperature lowering rate of 10 ° C./min. It is defined as the temperature (° C.) showing the maximum melting peak observed when the temperature is raised at a temperature rate of 10 ° C./min.

When Tm exceeds the range of the formula (1), the thermal dependency of the elastic modulus of the propylene / α-olefin copolymer is increased and the thermoformability is impaired, and when it is lower, the rigidity is insufficient. Here, Cx is a value (% by weight) measured by ¹³ C-NMR.

  In the propylene / α-olefin copolymer used in the present invention, the relationship between Cx and Tm preferably satisfies the following formula (4).

−22Cx + 171> Tm (4)
When Tm exceeds the range of the formula (4), the thermal dependence of the elastic modulus of the propylene / α-olefin copolymer is increased, and the thermoformability is impaired.

  The difference in melting temperature Tm between the propylene polymer of component A and the propylene / α-olefin copolymer of component B is 10 ° C or higher, preferably 13 ° C or higher, more preferably 16 ° C or higher. It is preferable to combine them as follows. If the difference in Tm is less than 10 ° C., the temperature range suitable for thermoforming may be narrowed.

  The propylene / α-olefin copolymer having such characteristics can be easily obtained by random copolymerization of propylene and α-olefin using a metallocene catalyst obtained by using a metallocene compound. As the olefin, ethylene, butene-1, pentene-1, hexene-1, octene-1, 4-methyl-pentene-1 and the like can be used, and among them, a random copolymer with ethylene is preferable. The amount of α-olefin added is adjusted so that the properties of the resulting propylene / α-olefin copolymer are within the scope of the present invention. The α-olefin content (Cx) in the copolymer is usually selected from the range of 0.3 to 2.0% by weight, preferably 0.6 to 1.8% by weight.

Examples of the metallocene catalyst include those comprising the following components (a) and (b), or those obtained by further combining component (c) in addition to (a) and (b) as necessary. be able to.
Component (a): Transition metal complex compound represented by the following structural formula (I) Component (b): Promoting the component (a) by reacting with a cocatalyst, ie, component (a) Compound component (c): Organoaluminum compound

（構造式（１）中、ＡおよびＡ’は共役五員環を含む配位子である。Ｑは架橋基であり、好ましくはアルキレン基、ジアルキルシリレン基、ジアルキルゲルミレン基、シラフルオレン基である。Ｍは周期表４〜６族、好ましくは４族の遷移金属原子、さらに好ましくは、ジルコニウム、ハフニウムである。ＸおよびＹは、ハロゲン原子若しくは炭化水素基などのシグマ（σ）性配位子である。Ａおよび／またはＡ’は共役五員環以外の副環を有していてもよく、好ましくはアズレニル基である。）
成分（ｂ）の助触媒は、遷移金属錯体化合物を活性化する成分で、遷移金属錯体化合物の補助配位子と反応して当該錯体を、オレフィン重合能を有する活性種に変換させうる化合物であり、具体的には下記（ｂ−１）〜（ｂ−４）が挙げられる。

(In Structural Formula (1), A and A ′ are ligands containing a conjugated five-membered ring. Q is a bridging group, preferably an alkylene group, a dialkylsilylene group, a dialkylgermylene group or a silafluorene group. M is a transition metal atom of Group 4-6 of the periodic table, preferably Group 4, more preferably zirconium or hafnium, and X and Y are sigma (σ) coordination such as halogen atom or hydrocarbon group. A and / or A ′ may have a secondary ring other than a conjugated five-membered ring, and is preferably an azulenyl group.)
The co-catalyst of component (b) is a component that activates the transition metal complex compound, and is a compound that reacts with the auxiliary ligand of the transition metal complex compound to convert the complex into an active species having olefin polymerization ability. Yes, specifically, the following (b-1) to (b-4) may be mentioned.

(B-1) Aluminum oxy compound (b-2) An ionic compound or Lewis acid capable of reacting with the transition metal complex compound (a) to convert the transition metal complex compound (a) into a cation (b-3) ) Solid acid (b-4) Ion exchange layered silicate (b-1) As a specific example of an aluminum oxy compound, a well-known alumoxane compound can be illustrated. More specifically, methylalumoxane, ethylalumoxane, propylalumoxane, butylalumoxane, isobutylalumoxane, methylethylalumoxane, methylbutylalumoxane, methylisobutylalumoxane and the like are exemplified.
Examples of the compound (b-2) include known boron compounds, more specifically, a reaction product of trialkylaluminum and alkylboronic acid, for example, a reaction product of 2: 1 of trimethylaluminum and methylboronic acid. And a 2: 1 reactant of triisobutylaluminum and methylboronic acid, a 1: 1: 1 reactant of trimethylaluminum, triisobutylaluminum and methylboronic acid, a 2: 1 reactant of triethylaluminum and butylboronic acid, and the like.

  Other examples of (b-2) include ionic compounds, and more specifically, cations such as carbonium cation and ammonium cation, and triphenylboron and tris (3,5-difluorophenyl) boron. And a complex with an organic boron compound such as tris (pentafluorophenyl) boron.

Examples of the solid acid (b-3) include alumina, silica-alumina, silica-magnesia and the like.
Examples of the ion-exchange layered compound (b-4) include silicates such as montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stevensite, bentonite, teniolite, and other smectites, vermiculite, and mica. Is used. These silicates are preferably subjected to chemical treatment. Here, as the chemical treatment, any of a surface treatment for removing impurities adhering to the surface and a treatment affecting the crystal structure and chemical composition of the layered silicate can be used.

  Specific examples include (i) acid treatment, (b) alkali treatment, (c) salt treatment, and (d) organic matter treatment. These treatments remove impurities on the surface, exchange cations between layers, elute cations such as Al, Fe, and Mg in the crystal structure, resulting in ion complexes, molecular complexes, organic derivatives, etc. The surface area, interlayer distance, solid acidity, etc. can be changed. These processes may be performed independently or two or more processes may be combined.

  Examples of the component (c) include organoaluminum compounds such as triethylaluminum, triisobutylaluminum, and diethylaluminum chloride.

  A detailed method for producing a metallocene catalyst comprising a combination of (a) to (c) and specific examples of each component are disclosed in, for example, JP-A-10-226712, JP-A-11-240909, and JP-A-11-240909. There are disclosures in Japanese Patent Application Laid-Open Nos. 2000-95791, 2002-12596, and 2003-292518.

  As a method for preparing the metallocene catalyst, the presence of a monomer to be polymerized in the polymerization tank or outside the polymerization tank of the metallocene catalyst comprising the component (a), the component (b) and the component (c) used as necessary. It can carry out by making it contact under or absence.

  Further, the catalyst may be one obtained by prepolymerization in the presence of olefin. As the olefin used for the prepolymerization, propylene, ethylene, 1-butene, 3-methylbutene-1, styrene, divinylbenzene, or the like is used.

  The polymerization method of the propylene / α-olefin copolymer of component B used in the present invention is carried out by mixing and contacting a metallocene catalyst and a required monomer. The amount ratio of each monomer in the reaction system does not need to be constant over time, it is convenient to supply each monomer at a constant mixing ratio, and the mixing ratio of the supplied monomers can be changed over time. Is also possible. Also, any of the monomers can be added in portions in consideration of the copolymerization reaction ratio.

  As the polymerization method, any method can be adopted as long as the catalyst component and each monomer come into efficient contact. Specifically, the slurry method using an inert solvent, the bulk method using propylene as a solvent substantially without using an inert solvent, the solution polymerization method, or the monomers are substantially gaseous without using a liquid solvent substantially. It is possible to employ a gas phase method that keeps the temperature constant.

  It is also applied to continuous polymerization and batch polymerization. In the case of slurry polymerization, a saturated aliphatic or aromatic hydrocarbon such as hexane, heptane, pentane, cyclohexane, benzene and toluene can be used alone or as a polymerization solvent.

  As polymerization conditions, the polymerization temperature is −78 to 160 ° C., preferably 0 to 150 ° C., and hydrogen can be supplementarily used as a molecular weight regulator at that time. The polymerization pressure is suitably from 0 to 9 MPaG, preferably from 0 to 6 MPaG, particularly preferably from 1 to 5 MPaG.

  In the present invention, it is preferable to add a crystal nucleating agent to the polymer composition in order to improve transparency and rigidity. As the crystal nucleating agent, an aromatic carboxylic acid metal salt, an aromatic phosphate metal salt, a sorbitol derivative, a metal salt of rosin, or the like is used. Among these nucleating agents, aluminum pt-butylbenzoate, sodium 2,2′-methylenebis (4,6-di-t-butylphenyl) phosphate, 2,2′-methylenebis (4,6) phosphate -Di-t-butylphenyl) aluminum, p-methyl-benzylidene sorbitol, p-ethyl-benzylidene sorbitol, sodium salt of rosin and the like are preferred.

  In addition, when the nucleating agent is added, the blending ratio is 0.01 to 1 with respect to 100 parts by weight of the polymer composition composed of a propylene polymer and a propylene / α-olefin copolymer. Part by weight, preferably 0.03 to 0.8 part by weight, particularly preferably 0.05 to 0.6 part by weight.

  If the blending amount of the crystal nucleating agent is less than the above range, the transparency may be insufficient. On the other hand, if the blending amount exceeds the above range, the transparency imparting effect will reach its peak, leading to a mere cost increase.

  In the present invention, in addition to the essential components, other additional components can be blended within a range that does not significantly impair the effects of the present invention. These optional components include antioxidants, light stabilizers, UV absorbers, lubricants, antistatic agents, antifogging agents, neutralizing agents, metal deactivators, colorants, dispersants used for ordinary polyolefins. , Peroxides, fillers, fluorescent brighteners and the like.

  The propylene polymer composition in the present invention is usually used as a resin component in a two-component system of component A and component B having the characteristics described above, but depending on the case, other resin components may be used. A small amount can be blended. For example, petroleum resin, elastomer, highly crystalline polypropylene resin, highly crystalline propylene resin having a propylene content of 99% or more, high density polyethylene resin, linear low density polyethylene resin, high pressure method low density polyethylene resin, etc. 0-5 It can be suitably used within a range of less than% by weight.

  The propylene-based polymer composition for sheet molding according to the present invention comprises component A and component B, and additional components to be blended as necessary, using a Henschel mixer, a super mixer, a V blender, a tumbler mixer, a ribbon blender, and a Banbury mixer. It can be adjusted by mixing or melt-kneading in a mixing or kneading machine such as a kneader blender or a single-screw or twin-screw extruder.

  As a method for producing the propylene-based polymer sheet of the present invention, an extrusion molding machine equipped with a commonly used T-die can be used. A specific example will be described with a T-type die molding machine. A polymer is supplied to an extruder, heated and melt-kneaded at a temperature of 190 to 260 ° C., and then extruded into a sheet form from a die lip of a T-type die. The molten sheet extruded by an air chamber method, a polishing roll method, a swing roll method, a belt cast method, a water cooling method or the like is cooled, and the sheet is produced by taking it out with a take-up machine.

  As a sheet take-up method, a belt casting method in which a metal belt is attached to one side or both sides and cooled with a narrow pressure is particularly preferable from the viewpoint of surface gloss and transparency. For example, the apparatus shown in FIG. 1 is used.

  The apparatus shown in FIG. 1 is arranged below the T-shaped die 2 so that the feed rolls 3a and 3b and the feed rolls 4a and 4b, which form a pair, face each other. The endless belt 5 is suspended and the back-up rolls 7a and 7b are in contact with the back surface of the endless belt in the middle of the feed rolls 3a and 3b to press the endless belt 5. Similarly, the endless belt 6 is suspended on the feed rolls 4a and 4b, pressed by the backup rolls 8a and 8b, and the endless belts 5 and 6 are configured to be clamped by the backup rolls 7a, 7b, 8a and 8b. Is done.

  When forming a propylene-based polymer sheet using such an apparatus, it is performed as follows. That is, a propylene polymer sheet 1 made of a molten propylene polymer composition of the present invention in a molten state is melt-extruded from a T-die 2 and the resulting propylene polymer sheet 1 is paired with an endless pair. The propylene according to the present invention is formed into a sheet by being clamped by the belts 5 and 6 and cooled while being fed downward by the endless belts 5 and 6 that run by the rotation of the feed rolls 3a, 3b, 4a, and 4b. A polymer sheet 1 is obtained.

  Moreover, the apparatus shown in FIG. 2 can also be used. The apparatus shown in FIG. 2 has a roll 9 as one endless belt. By pressing the endless belt 5 with the roll 9, the traveling distance of the propylene-based polymer sheet 1 is increased. can do.

  The propylene-based polymer sheet of the present invention may have a total thickness in the range of 0.1 to 3.0 mm, preferably 0.15 to 2.0 mm, particularly preferably 0.2 to 1.8 mm. If the thickness of the sheet exceeds this range, the transparency tends to decrease. If the thickness is less than the above range, the mechanical strength of the thermoformed product may be insufficient.

  The propylene-based polymer sheet of the present invention may be a multilayer extruder that simultaneously extrudes and molds two or more polymers in addition to a single-layer extruder. In this case, in addition to the essential layers described above, other layers can be added as long as the effects of the present invention are not impaired. Examples of the other layer include the polymer of the present invention, olefin polymers other than the present invention, recycled resin, gas barrier resin, and adhesive resin.

  The molded article of the present invention can also be improved in physical properties by applying an antistatic agent, an antifogging agent, a lubricant, etc. to the sheet surface at the sheet stage. Here, sucrose fatty acid ester or polyglycerin fatty acid ester can be used as the antifogging agent, and silicon oil or amide-based lubricant can be used as the lubricant.

  The secondary processed molded article of the present invention can be made into a secondary molded article such as a packaging container or a lid by subjecting the propylene polymer sheet of the present invention to secondary processing by a thermoforming method.

As a method of thermoforming a propylene-based polymer sheet, after the sheet is placed on the mold, a method of sucking from the outer surface side of the mold, a method of plug assisting with suction, or an air pressure from the inner surface side of the mold A so-called vacuum forming method or vacuum / pressure forming method such as a method of adding, a method of plug assisting to this, a method of using a combination of suction and pressurization by air, etc. can be adopted, but the pressure pressure is preferably ² kg / cm ² or more, preferably It is 2.5 kg / cm ² or more, more preferably 2.8 kg / cm ² or more.

  If the compressed air pressure is lower than the above range, the shape of the molded product may be incomplete, and there is a problem that transparency is impaired when the sheet temperature is raised to facilitate molding. The propylene-based polymer composition for sheet molding of the present invention is suitable for the production of a sheet for a secondary processed molded body, and the propylene-based polymer sheet of the present invention is formed by thermoforming foods, clothing, daily commodities. Can be widely used as packaging material for pharmaceuticals and other products.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.
[Example 1]
(Manufacture of component A)
(1) Preparation of catalyst and preparation of preactivated catalyst The catalyst used for the polymerization was prepared by the method described in Example 1 (1) of JP-B-7-39446. Preactivation was performed by the method described in Example 1 (2) of the publication.
(2) Polymerization Into a stainless steel polymerization vessel with an internal volume of 500 L with nitrogen replacement and max-blend blades, 240 L of n-hexane, 265 g of diethylaluminum chloride (DEAC), 28 g of the preactivated catalyst obtained in the preparation (1), p -23.7 g of methyl toluate were charged, and 460 NL of hydrogen was further added. Subsequently, after raising the temperature to 72 ° C., propylene was supplied to increase the total pressure to 0.8 MPaG. While maintaining the temperature at 72 ° C. and the pressure of 0.8 MPaG for 120 minutes, the first stage polymerization was performed, then the supply of propylene was stopped, the temperature in the polymerization vessel was cooled to room temperature, and hydrogen and unreacted propylene Was released. Next, 120 NL of hydrogen was added, the temperature was raised to 72 ° C., and propylene was supplied. The second stage polymerization was performed for 79 minutes while maintaining the total pressure at 1.0 MPaG, and then the supply of propylene was stopped. The temperature inside the polymerization vessel was cooled to room temperature, and hydrogen and unreacted propylene were released. Next, 30 NL of hydrogen was added, the temperature was raised to 72 ° C., and then propylene was supplied. While maintaining the total pressure at 1.0 MPaG, the third stage polymerization was performed for 142 minutes, and then the supply of propylene was stopped. Then, the temperature inside the polymerization vessel was cooled to room temperature, hydrogen and unreacted propylene were released, 50 L of methanol was added, and the mixture was stirred at 80 ° C. for 30 minutes, and then added with 500 ml of a 20 wt% NaOH aqueous solution, Stir for minutes. Next, it cooled to room temperature, 100 L of water was added, the slurry obtained by performing water washing and water separation 3 times was filtered, the polymer was dried, and the propylene polymer powder was obtained.

The obtained propylene polymer (component A) had an MFR of 0.6 g / 10 min, a density of 0.909 g / cm ³ , and a Q value of 9.8.

(Production of component B)
(1) Synthesis of metallocene compound Synthesis of (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azurenyl}] hafnium is disclosed in JP-A-11-240909. It carried out according to the method as described in the gazette.
(2) Chemical treatment of ion-exchangeable layered silicate 1,700 g of pure water was put into a 5 L separable flask equipped with a stirring blade and a reflux device, and 500 g of 98% sulfuric acid was added dropwise. Further, 300 g of commercially available granulated montmorillonite (Mizusawa Chemical Co., Ltd., Benclay SL, average particle size: 19.5 μm) was added and stirred. Thereafter, the mixture was reacted at 90 ° C. for 2 hours. This slurry was washed with an apparatus in which an aspirator was connected to Nutsche and a suction bottle. A 900 mL aqueous solution of 325 g of lithium sulfate monohydrate was added to the recovered cake and reacted at 90 ° C. for 2 hours. This slurry was washed to pH> 4 with an apparatus in which an aspirator was connected to Nutsche and a suction bottle. The collected cake was dried at 120 ° C. overnight. As a result, 270 g of a chemically treated product was obtained. Thereafter, the entire amount was put into a 2 L flask and dried under reduced pressure at 200 ° C. for 6 hours.

(3) Preparation of solid catalyst A mixture of 0.223 kg of the dried silicate obtained above and 1.45 liters of heptane was introduced into a metal reactor equipped with a stirrer having an internal volume of 13 liters, and heptane of triisobutylaluminum. 0.79 liter of solution (0.71M) was added, and the system temperature was maintained at 25 ° C. After the reaction for 1 hour, it was thoroughly washed with heptane to prepare 2.0 liters of a silicate slurry.

  To the slurry, 9.5 ml of a heptane solution of triisobutylaluminum (0.71 M) was added and stirred for 10 minutes. Further, a mixture prepared by adding 0.55 liters of heptane to 2.73 g of (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azurenyl}] hafnium in advance. After introduction and reaction at room temperature for 1 hour, heptane was added to adjust to 5.6 liters. Subsequently, propylene was supplied at a rate of 111.8 g / hour at a temperature of 40 ° C., and prepolymerization was performed for 4 hours. Further polymerization was carried out for 1 hour.

  After completion of the prepolymerization, the residual monomer was purged, and the catalyst was thoroughly washed with heptane. Subsequently, 95 mL of a heptane solution of triisobutylaluminum (0.71 M / L) was added, followed by drying at 40 ° C. under reduced pressure. By this operation, 0.656 kg of a prepolymerized catalyst containing 1.94 g of polypropylene per 1 g of dry silicate was obtained.

(4) Copolymerization of propylene / ethylene After the inside of the stirring autoclave having an internal volume of 200 liters was sufficiently substituted with propylene, 45 kg of sufficiently dehydrated liquefied propylene was introduced. To this, 0.63 kg of ethylene, 500 ml (0.12 mol) of a triisobutylaluminum / n-heptane solution, and 2.2 L of hydrogen (as a standard state volume) were added, and the internal temperature was maintained at 30 ° C. Next, 2.5 g of the prepolymerized catalyst was injected with argon to initiate polymerization, and the temperature was raised to 70 ° C. over 32 minutes. At the same time as the temperature reached 70 ° C., 0.132 g / hour of hydrogen was continuously fed. . The polymerization temperature was maintained at 70 ° C., and after 1.85 hours, 100 ml of ethanol was added to stop the reaction. The residual gas was purged to obtain 22.3 kg of a propylene / ethylene random copolymer having an MFR of 1.8 g / 10 min, an ethylene content of 1.1 wt%, and a Tm of 145.5 ° C.

(Sheet molding and evaluation)
Into 100 parts by weight of the polymer composition composed of 30% by weight of component A and 70% by weight of component B obtained above, 0.2 parts by weight of mark NA21 (manufactured by Asahi Denka Co., Ltd.) as a crystal nucleating agent and Irga as an antioxidant Nox 1010 (Ciba Specialty Chemicals Co., Ltd.) 0.1 parts by weight, calcium stearate 0.05 parts by weight as a neutralizing agent was added and mixed in a 250 ° C. screw extruder, and a propylene polymer for sheet molding A composition was obtained.

  This propylene-based polymer composition for sheet molding was extruded into a sheet from a extruder having a screw diameter of 65 mm heated to 230 ° C. by a T-type die having a width of 550 mm heated to 230 ° C., and then cast into a chrome-plated casting drum (inside 30 The sheet was sandwiched with cooling water at 0 ° C.), solidified by cooling, and taken up to obtain a sheet. The thickness of the sheet is 0.5 mm.

  For this sheet, the HAZE is measured according to JIS-K6758 to obtain a measure of transparency, the tensile elastic modulus is measured according to JIS-K7127, the bending elastic modulus is measured according to JIS-K7171, and the rigidity is measured. As a guide. Moreover, the DuPont impact strength was measured based on ASTM-D2794.

Further, the sheet, an indirect heating type pressure forming machine (Asano Laboratories Co., Ltd., Cosmic molding machine) was heated from above and below at 350 ° C. of the ceramic heater using, in conditions of pneumatic pressure 2.5 kg / cm ^2, a vertical A lid mold product was molded using a mold having a width of 13 cm, a width of 18 cm, and a depth of 1 cm. Here, the surface temperature was changed by changing the heating time, and the relationship between the surface temperature and the moldability was measured. The obtained molded product was visually observed, and thermoformability was evaluated according to the following criteria.
Evaluation result ○: Good reproducibility of mold shape and good transparency of molded product.
Δ: Mold shape is not reproduced due to insufficient heating.
X: The sheet melts due to overheating, and the transparency is poor.
A large number of ○ means that a good product can be molded in a wide surface temperature range, and it can be uniformly molded even if the heating temperature of a wide sheet or the like is uneven. The results are shown in Table 1.

[Example 2]
A propylene-based polymer composition for sheet molding was obtained according to Example 1 except that the blending ratio of Component A and Component B was changed to 20% by weight and 80% by weight, and a propylene-based polymer composition was obtained using the composition. A polymer sheet was obtained. In addition, various performance evaluations using the sheet were performed according to Example 1. The results are shown in Table 1.

[Example 3]
A propylene-based polymer composition for sheet molding was obtained according to Example 1 except that the blending ratio of Component A and Component B was changed to 50% by weight and 50% by weight, and a propylene-based polymer composition was obtained using the composition. A polymer sheet was obtained. In addition, various performance evaluations using the sheet were performed according to Example 1. The results are shown in Table 1.

[Example 4]
When obtaining a propylene polymer sheet, except that the cooling and solidification method at the time of sheet production was sandwiched between metal belts cooled by water spray at 15 ° C. from the inside, and the thickness of the obtained sheet was adjusted to 0.35 mm In accordance with Example 1, a sheet-forming propylene polymer composition was obtained, and a propylene polymer sheet was obtained using the composition. In addition, various performance evaluations using the sheet were performed according to Example 1. The results are shown in Table 1.

[Example 5]
(Manufacture of component B / copolymerization of propylene / ethylene)
After sufficiently replacing the inside of the stirring autoclave having an internal volume of 200 liters with propylene, 45 kg of sufficiently dehydrated liquefied propylene was introduced. To this was added 0.25 kg of ethylene, 500 ml (0.12 mol) of a triisobutylaluminum / n-heptane solution, and 1.6 L of hydrogen (as a standard state volume), and the internal temperature was maintained at 30 ° C. Next, 3.8 g of the prepolymerized catalyst prepared in (1) to (3) of Example 1 was injected with argon to initiate polymerization, and the temperature was raised to 70 ° C. over 38 minutes. At the same time, 0.10 g / hr of hydrogen was continuously fed. The polymerization temperature was maintained at 70 ° C., and after 2 hours, 100 ml of ethanol was added to stop the reaction. The residual gas was purged to obtain 21.7 kg of a propylene / ethylene random copolymer having an MFR of 1.5 g / 10 min, an ethylene content of 0.5% by weight, and a Tm of 148.9 ° C.

(Sheet molding and evaluation)
A propylene-based polymer composition for sheet molding was obtained according to Example 1 except that component B was replaced with the propylene / α-olefin copolymer produced above, and a propylene-based polymer was obtained using the composition. A sheet was obtained. In addition, various performance evaluations using the sheet were performed according to Example 1. The results are shown in Table 1.

[Comparative Example 1]
In place of the polymer composition used in Example 1, a propylene / ethylene copolymer having an ethylene content of 3.4% by weight, an MFR of 1.3 g / 10 min, and a Tm of 145 ° C. (Novatech PP “EG7F” manufactured by Nippon Polypro Co., Ltd.) A propylene-based polymer composition for sheet molding was obtained in the same manner as in Example 1 except that was used, and a sheet was obtained using the composition. Table 2 shows the results of various performance evaluations using the sheet.

  In addition, the propylene / ethylene copolymer used in this comparative example was produced with a Ziegler catalyst and has a Tm higher than −7.5Cx + 162 = 136.5 ° C.

[Comparative Example 2]
Instead of the propylene / ethylene copolymer used in Example 1, a propylene homopolymer having an MFR of 0.6 g / 10 min, a density of 0.908 g / cm ³ , a Tm of 166 ° C., and a Q value of 5.5 (manufactured by Nippon Polypro Co., Ltd., A propylene-based polymer composition for sheet molding was obtained in the same manner as in Example 1 except that Novatec PP “EA9H”) was used, and a sheet was obtained using the composition. Table 2 shows the results of various performance evaluations using the sheet.

[Comparative Example 3]
Instead of the polymer composition used in Example 1, an ethylene content of 2.6% by weight, an MFR of 2.0 g / 10 min, and a Tm of 125 ° C. propylene / ethylene copolymer (manufactured by Nippon Polypro Co., Ltd., Wintech “WFX6”) A propylene-based polymer composition for sheet molding was obtained in the same manner as in Example 1 except that was used, and a sheet was obtained using the composition. Table 2 shows the results of various performance evaluations using the sheet.

  The propylene / ethylene copolymer used in this comparative example was produced with a metallocene catalyst, and has a Tm lower than −7.5Cx + 146 = 12.6 ° C.

[Comparative Example 4]
The ethylene content used in Comparative Example 1 was 3.4 wt%, MFR 1.3 g / 10 min, Tm 145 ° C. propylene / ethylene copolymer (manufactured by Nippon Polypro Co., Ltd., Novatec PP “EG7F”), 70 wt%, manufactured as follows: A propylene-based polymer composition for sheet molding was obtained in the same manner as in Example 1 except that a mixed composition of 30% by weight of the propylene homopolymer was used, and a sheet was obtained using the composition. Table 2 shows the results of various performance evaluations using the sheet.

<Production of propylene homopolymer used in Comparative Example 4>
(1) Preparation of catalyst and preparation of pre-activated catalyst The catalyst used for polymerization was prepared by the method described in Example 1 (1) of JP-B-7-39446. Preactivation was carried out by the method described in Example 1 (2) of the same report.
(2) Polymerization Into a stainless steel polymerization vessel equipped with a nitrogen blended internal volume 500 L max blend blade, 240 L of n-hexane, 265 g of diethylaluminum chloride (DEAC), 28 g of the preactivated catalyst obtained in the preparation (1), P -23.7 g of methyl toluate were charged, and 460 NL of hydrogen was further added. Subsequently, after raising the temperature to 72 ° C., propylene was supplied to increase the total pressure to 0.8 MPaG. While maintaining the temperature at 72 ° C. and the pressure at 0.8 MPaG, the first stage polymerization was performed for 120 minutes, then the supply of propylene was stopped, the temperature in the polymerization vessel was cooled to room temperature, and hydrogen and unreacted propylene were removed. Released. Next, 120 NL of hydrogen was added, and the temperature was raised to 72 ° C., and then propylene was supplied. While maintaining the total pressure at 1.0 MPaG, the second stage polymerization was performed for 79 minutes, and then the supply of propylene was stopped. The temperature inside the polymerization vessel was cooled to room temperature, and hydrogen and unreacted propylene were released. Next, 30 NL of hydrogen was added, and after raising the temperature to 72 ° C., propylene was supplied, and the third stage polymerization was performed for 142 minutes while maintaining the total pressure at 1.0 MPaG, and then the supply of propylene was stopped, The temperature inside the polymerization vessel was cooled to room temperature, hydrogen and unreacted propylene were released, 50 L of methanol was added, and the mixture was stirred at 80 ° C. for 30 minutes. Stir. Next, it cooled to room temperature, 100 L of water was added, the slurry obtained by performing water washing and water separation 3 times was filtered, the polymer was dried, and the propylene polymer powder was obtained.

The obtained propylene homopolymer had an MFR of 0.6 g / 10 min, a density of 0.909 g / cm ³ , and a Q value of 9.8.

[Comparative Example 5]
The ethylene content used in Comparative Example 3 was 2.6% by weight, MFR 2.0 g / 10 min, Tm 125 ° C. propylene / ethylene copolymer (Nippon Polypro, Wintec “WFX6”) 70% by weight, and MFR 1.9 g. / 10 minutes, a density of 0.907 g / cm ³ , a propylene homopolymer having a Q value of 4.5 (manufactured by Nippon Polypro Co., Ltd., Novatec PP “FY6H”) 30% by weight. Similarly, a propylene polymer composition for sheet molding was obtained, and a sheet was obtained using the composition. Table 2 shows the results of various performance evaluations using the sheet.

[Comparative Example 6]
Instead of the propylene polymer (Q value 9.8) used as component A in Example 1, the propylene homopolymer weight of MFR 0.6 g / 10 min, density 0.908 g / cm ³ , Tm 166 ° C., Q value 5.5 A propylene-based polymer composition for sheet molding was obtained in the same manner as in Example 1 except that the coalesced (manufactured by Nippon Polypro, Novatec PP “EA9H”) was used, and a sheet was obtained using the composition. Table 2 shows the results of various performance evaluations using the sheet.

  From the above results, it is understood that the propylene-based polymer composition for sheet molding of the present invention has an excellent performance balance in rigidity, transparency, and thermoformability (secondary workability). On the other hand, when a polymer composition deviating from the performance specified by the present invention is used, one or more performances of rigidity, transparency and thermoformability (secondary processability) deteriorate, and secondary process molding is performed. It turns out that it becomes unsuitable for body use.

Side view showing an example of a method for forming a propylene-based polymer composition into a sheet Side view showing another example of a method for forming a propylene-based polymer composition into a sheet

Explanation of symbols

1: Propylene polymer sheet 2: T-shaped dies 3a, 3b: feed rolls 4a, 4b: feed rolls 5, 6: endless belts 7a, 7b: backup rolls 8a, 8b: backup rolls

Claims (11)

A propylene-based polymer composition for sheet molding comprising a polymer composition containing 5 to 60% by weight of the following component A and 40 to 95% by weight of component B.
Component A: a propylene polymer having a melt flow rate (MFR) of 0.1 to 20 g / 10 min, a density of 0.905 g / cm ³ or more, and a Q value of 7 or more,
Component B: a propylene / α-olefin copolymer satisfying the following formula (1) at a melt flow rate (MFR) of 0.1 to 20 g / 10 min, a melting temperature (Tm) of 110 to 155 ° C.,
−7.5Cx + 146 ≦ Tm ≦ −7.5Cx + 162 (1)
[However, Cx represents the α-olefin content (% by weight) of the propylene / α-olefin copolymer. ]   The propylene-based polymer composition for sheet molding according to claim 1, wherein the α-olefin content (Cx) is 0.3 to 2.0% by weight.   The propylene polymer composition for sheet molding according to claim 1 or 2, wherein the melting temperature (Tm) is 140 to 155 ° C.   The propylene polymer composition for sheet molding according to claim 1, wherein the propylene polymer is a propylene homopolymer or a propylene / α-olefin copolymer having a propylene content of 99.0% by weight or more.   The propylene-based polymer composition for sheet molding according to any one of claims 1 to 4, wherein the propylene / α-olefin copolymer is a propylene / ethylene copolymer.   The propylene for sheet molding according to any one of claims 1 to 5, wherein a crystal nucleating agent is blended in an amount of 0.01 to 1.00 parts by weight with respect to 100 parts by weight of the polymer composition. -Based polymer composition. Propylene-based weight obtained by molding a propylene-based polymer composition for sheet molding comprising a polymer composition containing 5 to 60% by weight of the following component A and 40 to 95% by weight of component B Combined sheet.
Component A: a propylene polymer having a melt flow rate (MFR) of 0.1 to 20 g / 10 min, a density of 0.905 g / cm ³ or more, and a Q value of 7 or more,
Component B: a propylene / α-olefin copolymer having a melt flow rate (MFR) of 0.1 to 20 g / 10 minutes, a melting temperature (Tm) of 110 to 155 ° C. and satisfying the following formula (1):
−7.5Cx + 146 ≦ Tm ≦ −7.5Cx + 162 (1)
[However, Cx represents the α-olefin content (% by weight) of the propylene / α-olefin copolymer. ]   The propylene-based polymer sheet according to claim 7, wherein 0.01 to 1.00 parts by weight of a crystal nucleating agent is blended with 100 parts by weight of the polymer composition.   The propylene-based polymer sheet according to claim 7 or 8, wherein the sheet has a thickness of 0.1 to 3.0 mm.   The propylene-based polymer composition for sheet molding according to any one of claims 1 to 6 is melt-extruded using a T-shaped die, and at least one surface of the extruded sheet is clamped with a metal belt to be cooled and solidified. A method for producing a propylene-based polymer sheet characterized by the above. The secondary processing molded object formed by vacuum-forming or vacuum-pressure forming the propylene-type polymer sheet of any one of Claims 7-9 under the shaping | molding temperature of 130 degreeC or more.

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