Polypropylene wax

Abstract

To provide a polyolefin wax with superior handleability and mechanical strength.SOLUTION: A polypropylene wax is either a homopolymer of propylene or a copolymer of propylene with ethylene or an α-olefin having 4 or more carbon atoms. The weight average molecular weight (Mw) is 1000 or more and 25000 or less. The softening point is 110°C or higher and 155°C or lower.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polypropylene wax. [Background technology]

[0002] Conventionally, an acid-modified polyolefin wax has been known as a dispersant, and by blending such an acid-modified polyolefin wax with a resin composition containing a filler, the dispersibility of the filler can be improved.

[0003] The acid-modified polyolefin wax can be obtained, for example, by modifying a polypropylene wax with an unsaturated carboxylic acid.

[0004] As the polypropylene wax, a polypropylene wax having a melt viscosity of 1500 mPa·s and a softening point of 131° C. has been proposed (see, for example, Example 8 of Patent Document 1).

[0005] Since the melt viscosity of the polypropylene wax in Patent Document 1 is 1,500 mPa·s, the weight average molecular weight is estimated to be approximately 38,000. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2001-504542 Summary of the Invention [Problem to be solved by the invention]

[0007] On the other hand, since the weight average molecular weight of the polypropylene wax in Patent Document 1 is large, when an acid-modified polyolefin wax obtained using this polypropylene wax is added to a resin composition, there is a problem that the fluidity decreases and the handleability decreases.

[0008] Furthermore, the resin composition containing the acid-modified polyolefin wax is required to have good mechanical strength.

[0009] The present invention provides a polyolefin wax that is excellent in handleability and mechanical strength. [Means for solving the problem]

[0010] The present invention [1] is a polypropylene wax which is a propylene homopolymer or a copolymer of propylene and ethylene or an α-olefin having 4 or more carbon atoms, and has a weight average molecular weight (Mw) of 1,000 or more and 25,000 or less, and a softening point of 110°C or more and 155°C or less.

[0011] The present invention [2] contains the polypropylene wax according to the above [1], which has a molecular weight dispersity (Mw / Mn) of 1.5 or more and 2.5 or less.

[0012] The present invention [3] contains the polypropylene wax described in [1] or [2] above, in which the melting point is 100°C or higher and 155°C or lower.

[0013] The present invention [4] includes the polypropylene wax according to any one of the above [1] to [3], in which the softening point and the weight average molecular weight (Mw) satisfy the following formula (1): Softening point ≧0.00209×Mw+90 (1)

[0014] The present invention [5] contains the polypropylene wax according to any one of the above [1] to [4], wherein the weight average molecular weight (Mw) is 5,000 or more and 20,000 or less.

[0015] The present invention [6] contains the polypropylene wax according to any one of the above [1] to [5], wherein the melting point is 120°C or higher and 150°C or lower.

[0016] The present invention [7] contains the polypropylene wax according to any one of the above [1] to [6], in which the structural units derived from propylene account for 98 mol % or more. Effect of the Invention

[0017] The weight average molecular weight of the polyolefin wax of the present invention is at least 1000. Therefore, when an acid-modified polyolefin wax obtained by using this polyolefin wax is added to a resin composition, the mechanical strength can be improved.

[0018] In addition, the weight average molecular weight of this polyolefin wax is 25000 or less. Therefore, when the acid-modified polyolefin wax obtained by using this polyolefin wax is added to a resin composition, the decrease in fluidity can be suppressed. As a result, the handleability can be improved.

[0019] In addition, the softening point of this polyolefin wax is not less than 110° C. Therefore, when an acid-modified polyolefin wax obtained by using this polyolefin wax is added to a resin composition, the mechanical strength can be improved.

[0020] In addition, the softening point of this polyolefin wax is not higher than 155° C. Therefore, when the acid-modified polyolefin wax obtained using this polyolefin wax is added to a resin composition, it has excellent handleability. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a graph showing the relationship between melt viscosity (170° C.) and weight average molecular weight in polyolefin wax. [Diagram 2] FIG. 2 is a graph showing the relationship between the weight average molecular weight and the softening point of the polyolefin waxes of the respective Examples and Comparative Examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] <Polyolefin wax> Polyolefin wax is a raw material for acid-modified polyolefin wax (described later). As will be described in detail later, the acid-modified polyolefin wax (described later) is obtained by modifying polyolefin wax with an unsaturated carboxylic acid.

[0023] Polyolefin waxes are polymers of polymeric components.

[0024] Examples of the polymerization components include ethylene, propylene, and α-olefins having 4 or more carbon atoms.

[0025] Examples of the α-olefins having 4 or more carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 1-dodecene.

[0026] There are no particular limitations on the origin of the above polymerization components (ethylene, propylene, and α-olefins having 4 or more carbon atoms), and for example, monomers derived from fossil fuels or monomers derived from biomass can be used.

[0027] Such polymerization components can be used alone or in combination of two or more kinds.

[0028] In other words, the polyolefin wax may be composed only of monomers derived from fossil fuels, may be composed only of monomers derived from biomass, or may use a combination of monomers derived from fossil fuels and monomers derived from biomass.

[0029] Fossil fuels are oil, coal, natural gas, shale gas or combinations thereof.Biomass is any renewable natural source and its residues, such as from plants or animals, including fungi, yeasts, algae and bacteria.

[0030] Such polyolefin waxes are propylene homopolymers or copolymers of propylene with ethylene or with an α-olefin having 4 or more carbon atoms.

[0031] In other words, examples of polyolefin waxes include copolymers of ethylene and propylene, propylene homopolymers, copolymers of propylene and an α-olefin having 4 to 12 carbon atoms, and copolymers of ethylene, propylene and an α-olefin having 4 to 12 carbon atoms.

[0032] When an acid-modified polyolefin wax (described later) obtained by using this polyolefin wax is added to a resin composition (described later), from the viewpoint of improving mechanical strength, preferred examples of the polyolefin wax include a propylene homopolymer and a copolymer of ethylene and propylene. That is, the polymerization component is preferably composed of propylene or ethylene and propylene.

[0033] When the polyolefin wax is a copolymer of ethylene and propylene, the content of the ethylene-derived structural units relative to the total amount of 100 mol% of the ethylene-derived structural units and the propylene-derived structural units is, for example, 0.1 mol% or more, preferably 1 mol% or more, and, for example, 10 mol% or less, preferably 5 mol% or less, more preferably 2 mol% or less. Also, relative to the total amount of 100 mol% of the ethylene-derived structural units and the propylene-derived structural units, the content of the propylene-derived structural units is, for example, 90 mol% or more, preferably 95 mol% or more, more preferably 98 mol% or more, and, for example, 99.9 mol% or less, preferably 99 mol% or less.

[0034] That is, more preferably, the polyolefin wax contains 98 mol % or more of structural units derived from propylene.

[0035] If the structural unit derived from propylene is 98 mol % or more, the handleability can be improved when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later).

[0036] The method for measuring the contents of the structural units derived from ethylene and the structural units derived from propylene will be described in detail in the Examples described later.

[0037] As the polyolefin wax, a propylene homopolymer is more preferable.

[0038] The polyolefin wax can be obtained by polymerizing the polymerization components in the presence of an olefin polymerization catalyst.

[0039] The olefin polymerization catalyst comprises a transition metal compound.

[0040] Examples of the transition metal compound include the transition metal compounds listed in WO 2014 / 050816.

[0041] As the transition metal compound, preferably, there is mentioned a transition metal compound represented by the following general formula (1). [ka]

[0042] The olefin polymerization catalyst preferably comprises an organoaluminum compound.

[0043] Examples of the organoaluminum compounds include trialkylaluminum, dialkylaluminum hydride, and tricycloalkylaluminum. Examples of the trialkylaluminum include trimethylaluminum, triethylaluminum, and triisobutylaluminum. Examples of the dialkylaluminum hydride include diisobutylaluminum hydride.

[0044] As the organoaluminum compound, preferably, trialkylaluminum is used, and more preferably, triisobutylaluminum is used.

[0045] The organoaluminum compounds can be used alone or in combination of two or more kinds.

[0046] The polymerization method is preferably solution polymerization.

[0047] In solution polymerization, the polymerization components are polymerized in the presence of a solvent (e.g., cyclohexane, n-hexane). Preferably, the polymerization components and an olefin polymerization catalyst (a transition metal compound and an organoaluminum compound, if necessary) are continuously supplied to the solvent in a reaction vessel to polymerize the polymerization components continuously.

[0048] The supply amount of the solvent is, for example, 1 L / hour or more and, for example, 50 L / hour or less.

[0049] In particular, when the solvent is n-hexane, the supply amount of the solvent is, for example, 1 L / hour or more, preferably 20 L / hour or more, preferably 30 L / hour or more, more preferably 40 L / hour or more, and, for example, 50 L / hour or less.

[0050] Furthermore, when the solvent is cyclohexane or n-hexane, the amount of the solvent supplied is, for example, 1 L / hour or more, preferably 2 L / hour or more, and for example, 50 L / hour or less, preferably 30 L / hour or less, more preferably 10 L / hour or less, and even more preferably 5 L / hour or less.

[0051] The mixing ratio of the transition metal compound is, for example, 10 -10 mol or more, preferably 10 -8 Molar or more, e.g., 10 -2 mol or less, preferably 10 -3 It is less than a mole.

[0052] The supply amount of the transition metal compound is, for example, 0.001 mmol / hour or more, preferably 0.005 mmol / hour or more, more preferably 0.010 mmol / hour or more, even more preferably 0.020 mmol / hour or more, and for example, 0.300 mmol / hour or less, preferably 0.100 mmol / hour or less, more preferably 0.070 mmol / hour or less, even more preferably 0.060 mmol / hour or less.

[0053] The supply amount of the organoaluminum compound is, for example, 1 mmol / hour or more, preferably 5 mmol / hour or more, more preferably 10 mmol / hour or more, even more preferably 12 mmol / hour or more, and for example, 100 mmol / hour or less, preferably 50 mmol / hour or less, more preferably 30 mmol / hour or less, even more preferably 20 mmol / hour or less, and particularly preferably 15 mmol / hour or less.

[0054] The molar ratio of the organoaluminum compound to the transition metal compound (organoaluminum compound / transition metal compound) is, for example, 1 or more, more preferably 10 or more, even more preferably 50 or more, particularly preferably 100 or more, most preferably 200 or more, even more preferably 280 or more, even more preferably 340 or more, and for example, 50,000 or less, preferably 20,000 or less, more preferably 10,000 or less, even more preferably 5,000 or less, particularly preferably 1,000 or less, even more preferably 500 or less.

[0055] The polymerization temperature is, for example, 60°C or more, preferably 70°C or more, more preferably 80°C or more, even more preferably 100°C or more, and for example, 170°C or less, preferably 150°C or less, more preferably 130°C or less, even more preferably 125°C or less, particularly preferably 120°C or less, and most preferably 110°C or less.

[0056] The polymerization pressure is, for example, 0.1 MPa or more, preferably 0.5 MPa or more, and for example, 10 MPa or less, preferably 5 MPa or less, more preferably 2 MPa or less.

[0057] In this method, hydrogen is supplied from the viewpoint of adjusting the molecular weight, and the weight average molecular weight of the polyolefin wax can be reduced by supplying hydrogen.

[0058] The amount of hydrogen supplied is, for example, 1 NL / hour or more, preferably 10 NL / hour or more, more preferably 30 NL / hour or more, even more preferably 100 NL / hour or more, particularly preferably 180 NL / hour or more, and most preferably 220 NL / hour or more, and for example, 600 NL / hour or less, preferably 300 NL / hour or less, more preferably 250 NL / hour or less.

[0059] Furthermore, from the viewpoint of reliably lowering the weight average molecular weight of the polyolefin wax (specifically, making it 25,000 or less), the ratio of the amount of hydrogen supplied to the amount of transition metal compound supplied (amount of hydrogen supplied / amount of transition metal compound supplied) is adjusted to, for example, 1,000 or more, preferably 3,000 or more, more preferably 5,000 or more, even more preferably 6,000 or more, and for example, 8,000 or less, preferably 7,000 or less.

[0060] The extraction rate of the polyolefin wax is, for example, 0.5 kg / hour or more, preferably kg / hour or more, and, for example, 500 kg / hour or less, preferably 100 kg / hour or less, more preferably 10 kg / hour or less, even more preferably 5 kg / hour or less, and particularly preferably 2 kg / hour or less.

[0061] This produces a polyolefin wax.

[0062] The viscosity average molecular weight (Mv) of the polyolefin wax is, for example, 1,000 or more, preferably 5,000 or more, more preferably 7,000 or more, and for example, 20,000 or less, preferably 10,000 or less, more preferably 8,000 or less, and even more preferably 7,500 or less.

[0063] The weight average molecular weight (Mw) of the polyolefin wax is 1000 or more, preferably 3000 or more; from the viewpoint of further improving mechanical strength, it is more preferably 5000 or more, even more preferably 7000 or more, particularly preferably 10000 or more, and most preferably 10200 or more; and it is 25000 or less, preferably 23000 or less; from the viewpoint of further improving handleability, it is more preferably 20000 or less, even more preferably 15000 or less, particularly preferably 12000 or less, and most preferably 10800 or less.

[0064] When the weight average molecular weight (Mw) of the polyolefin wax is equal to or higher than the above lower limit, the mechanical strength can be improved when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later).

[0065] On the other hand, if the weight average molecular weight (Mw) of the polyolefin wax is less than the above lower limit, when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later), the mechanical strength decreases.

[0066] In addition, if the weight average molecular weight (Mw) of the polyolefin wax is equal to or less than the upper limit, when an acid-modified polyolefin wax (described later) obtained by using this polyolefin wax is added to a resin composition (described later), the decrease in fluidity can be suppressed, and as a result, the handleability can be improved.

[0067] On the other hand, if the weight average molecular weight (Mw) of the polyolefin wax exceeds the upper limit, when an acid-modified polyolefin wax (described later) obtained by using this polyolefin wax is added to a resin composition (described later), the decrease in fluidity cannot be suppressed, resulting in a decrease in handleability.

[0068] The weight average molecular weight (Mw) is a polystyrene-equivalent molecular weight determined by gel permeation chromatography (GPC) (the same applies hereinafter).

[0069] The number average molecular weight (Mn) of the polyolefin wax is, from the viewpoint of further improving the mechanical strength, for example, 500 or more, preferably 800 or more, more preferably 1000 or more, even more preferably 3000 or more, particularly preferably 5000 or more, and most preferably 5200 or more, and from the viewpoint of further improving the handleability, for example, 10000 or less, preferably 8000 or less, more preferably 6000 or less, and even more preferably 5500 or less.

[0070] The number average molecular weight (Mn) is a polystyrene-equivalent molecular weight determined by gel permeation chromatography (hereinafter the same).

[0071] The molecular weight dispersity (weight average molecular weight (Mw / number average molecular weight (Mn)) is, for example, 1.5 or more, preferably 1.8, more preferably 1.9 or more, even more preferably 2.0 or more, and for example, 4.0 or less, preferably 3.0 or less, more preferably 2.5 or less, even more preferably 2.2 or less.

[0072] If the molecular weight dispersity is within the above range, the influence of low molecular weight components that cause deterioration of physical properties and high molecular weight components that cause poor appearance can be suppressed, resulting in improved processability and appearance.

[0073] The softening point (JIS K2207) of the polyolefin wax is 110° C. or higher, preferably 120° C. or higher, more preferably 130° C. or higher, even more preferably 140° C. or higher, and is 155° C. or lower, preferably 142° C. or lower.

[0074] If the softening point of the polyolefin wax is equal to or higher than the above lower limit, the mechanical strength can be improved when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later).

[0075] On the other hand, if the softening point of the polyolefin wax is below the lower limit, the mechanical strength decreases when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later).

[0076] Furthermore, if the softening point of the polyolefin wax is not more than the above upper limit, the handleability is improved when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later).

[0077] On the other hand, if the softening point of the polyolefin wax exceeds the above upper limit, the handleability decreases when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later).

[0078] Preferably, the softening point and the weight average molecular weight (Mw) satisfy the following relational expression (1). Softening point ≧0.00209×Mw+90 (1)

[0079] If the softening point and the weight average molecular weight (Mw) satisfy the above-mentioned relational expression (1), when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later), both the handleability and the mechanical strength can be reliably improved.

[0080] More preferably, the softening point and the weight average molecular weight (Mw) satisfy the following relational expression (2). Softening point ≧0.00209×Mw+100 (2)

[0081] If the softening point and the weight average molecular weight (Mw) satisfy the above-mentioned relational expression (2), when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later), both the handleability and the mechanical strength can be improved more reliably.

[0082] More preferably, the softening point and the weight average molecular weight (Mw) satisfy the following relational expression (3). Softening point ≧0.00209×Mw+115 (3)

[0083] If the softening point and the weight average molecular weight (Mw) satisfy the above-mentioned relational expression (3), when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later), both the handleability and the mechanical strength can be improved more reliably.

[0084] The melting point of the polyolefin wax is, for example, 100°C or higher, and from the viewpoint of further improving mechanical strength, it is preferably 120°C or higher, and more preferably 125°C or higher, and from the viewpoint of further improving handleability, it is, for example, 155°C or lower, and from the viewpoint of further improving handleability, it is preferably 150°C or lower, and more preferably 140°C or lower, and even more preferably 135°C or lower.

[0085] The melting point of the polyolefin wax can be measured by differential scanning calorimetry (DSC).

[0086] The heat of fusion of the polyolefin wax is, for example, 50 mJ / mg or more, preferably 60 mJ / mg or more, more preferably 70 mJ / mg or more, even more preferably 80 mJ / mg or more, particularly preferably 90 mJ / mg or more, and for example, 120 mJ / mg or less, preferably 100 mJ / mg or less.

[0087] The heat of fusion of the polyolefin wax can be measured by differential scanning calorimetry (DSC).

[0088] The stereoregularity (mesopentad fraction) of the polyolefin wax is, for example, 70% or more, preferably 80% or more, more preferably 85% or more, and for example, 90% or less.

[0089] The stereoregularity (mesopentad fraction) of polyolefin wax is as follows: 13 It can be measured by C-NMR spectroscopy.

[0090] This polyolefin wax has a predetermined weight average molecular weight and a predetermined softening point, and therefore when an acid-modified polyolefin wax (described later) obtained using this polyolefin wax is added to a resin composition (described later), both the handleability and the mechanical strength can be improved.

[0091] The acid-modified polyolefin wax obtained by using this polyolefin wax and the resin composition containing this acid-modified polyolefin wax will be described in detail below.

[0092] <Acid-modified polyolefin wax> The acid-modified polyolefin wax can be obtained by modifying the above-mentioned polyolefin wax with an unsaturated carboxylic acid.

[0093] The unsaturated carboxylic acid may, for example, be an unsaturated carboxylic acid having 3 to 8 carbon atoms. Examples of the unsaturated carboxylic acid having 3 to 8 carbon atoms include monobasic acids and dibasic acids. Examples of the monobasic acids include (meth)acrylic acid (acrylic acid and / or methacrylic acid), crotonic acid, and isocrotonic acid. Examples of the dibasic acids include maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, allylsuccinic acid, nadic acid, methylnadic acid, tetrahydrofumaric acid, and methylhexahydrophthalic acid.

[0094] Furthermore, the unsaturated carboxylic acid may be an acid anhydride of the above-mentioned unsaturated carboxylic acid.

[0095] As the unsaturated carboxylic acid, preferably, an acid anhydride of an unsaturated carboxylic acid is used. As the unsaturated carboxylic acid, more preferably, an acid anhydride of a dibasic acid is used. As the unsaturated carboxylic acid, further preferably, maleic anhydride is used.

[0096] The unsaturated carboxylic acids can be used alone or in combination of two or more kinds.

[0097] The acid-modified polyolefin wax can be obtained by reacting the polyolefin wax with an unsaturated carboxylic acid, in which the unsaturated carboxylic acid is grafted onto the polyolefin wax.

[0098] Specifically, first, the polyolefin wax is melted at, for example, 100°C or higher, preferably 150°C or higher, and for example, 180°C or lower.

[0099] Then, maleic anhydride and a radical polymerization initiator are added, heated and stirred.

[0100] The mixing ratio of maleic anhydride relative to 100 parts by mass of the polyolefin wax is, for example, 1 part by mass or more, preferably 5 parts by mass or more, and for example, 15 parts by mass or less, preferably 8 parts by mass or less.

[0101] The radical polymerization initiator may, for example, be an organic peroxide (eg, di-tert-butyl peroxide).

[0102] The mixing ratio of the radical polymerization initiator relative to 100 parts by mass of the polyolefin wax is, for example, 1 part by mass or more, and for example, 5 parts by mass or less, preferably 3 parts by mass or less.

[0103] The radical polymerization initiators can be used alone or in combination of two or more kinds.

[0104] As for the heating conditions, the heating temperature is, for example, 100° C. or more, preferably 150° C. or more, and for example, 200° C. or less, preferably 180° C. or less. The heating time is, for example, 0.5 hours or more, and for example, 6 hours or less.

[0105] In this way, an acid-modified polyolefin wax is produced.

[0106] The viscosity average molecular weight (Mv) of the acid-modified polyolefin wax is, for example, 10,000 or more, preferably 12,000 or more, and for example, 20,000 or less, preferably 15,000 or less.

[0107] The weight average molecular weight of the acid-modified polyolefin wax is, for example, 2000 or more, preferably 5000 or more, more preferably 9000 or more, and for example, 20000 or less, preferably 10000 or less, more preferably 9700 or less.

[0108] When the weight average molecular weight of the acid-modified polyolefin wax is equal to or higher than the above lower limit, the mechanical strength can be improved.

[0109] In addition, when the weight average molecular weight of the acid-modified polyolefin wax is equal to or less than the above upper limit, the viscosity of the acid-modified polyolefin wax can be prevented from becoming excessively high, and the wax has excellent handleability.

[0110] The acid value (JIS K5902) of the acid-modified polyolefin wax is, for example, 20 mgKOH / g or more, preferably 30 mgKOH / g or more, more preferably 40 mgKOH / g or more, and for example, 70 mgKOH / g or less, preferably 50 mgKOH / g or less.

[0111] When the acid value of the acid-modified polyolefin wax is equal to or higher than the above lower limit, the dispersibility can be improved.

[0112] In addition, if the acid value of the acid-modified polyolefin wax is equal to or less than the upper limit, the interaction with the filler (described later) can be prevented from becoming excessively strong, and as a result, the viscosity can be prevented from increasing excessively, resulting in excellent handleability.

[0113] The number average molecular weight of the acid-modified polyolefin wax is, for example, 400 or more, preferably 800 or more, and for example, 10,000 or less, preferably 5,000 or less.

[0114] The molecular weight distribution polydispersity (Mw / Mn) of the acid-modified polyolefin wax is, for example, 6.0 or less, preferably 5.0 or less, more preferably 4.0 or less, still more preferably 3.0 or less, and for example, 2.0 or more.

[0115] The softening point (JIS K2207) of the acid-modified polyolefin wax is, for example, 110°C or more, preferably 120°C or more, more preferably 130°C or more, even more preferably 135°C or more, and is 155°C or less, preferably 140°C or less.

[0116] When the softening point of the acid-modified polyolefin wax is equal to or higher than the above lower limit, the heat resistance and mechanical strength can be improved.

[0117] In addition, when the softening point of the acid-modified polyolefin wax is equal to or lower than the above upper limit, in the production of the resin composition described later, the acid-modified polyolefin wax melts earlier than other polyolefin polymers (described later), making it easier to coat the surface of the filler, and improving dispersibility.

[0118] <Resin composition> The resin composition contains an acid-modified polyolefin wax, another polyolefin polymer, and a filler.

[0119] <Acid-modified polyolefin wax> The acid-modified polyolefin wax is a dispersant for the filler.

[0120] The content ratio of the acid-modified polyolefin wax, relative to 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other polyolefin polymer, and the filler, is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, more preferably 1.0 part by mass or more, and for example, 30 parts by mass or less, preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less.

[0121] <Other polyolefin polymers> The other polyolefin polymer is the base polymer in the resin composition.

[0122] Examples of the other polyolefin polymer include a copolymer of ethylene and propylene, a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, a homopolymer of propylene, a copolymer of propylene and an α-olefin having 4 to 12 carbon atoms, and a copolymer of ethylene, propylene and an α-olefin having 4 to 12 carbon atoms. A preferable example of the other polyolefin polymer is a homopolymer of propylene.

[0123] The other polyolefin polymer can be obtained, for example, by the method described in International Publication WO 2004 / 87775. Specifically, the other polyolefin polymer can be obtained by polymerizing raw material components (ethylene, propylene, and an α-olefin having 4 to 12 carbon atoms) in the presence of a metallocene catalyst.

[0124] The content ratio of the other polyolefin polymer is, for example, 29.9 parts by mass or more, preferably 40 parts by mass or more, and more preferably 45 parts by mass or more, and for example, 99.8 parts by mass or less, preferably 60 parts by mass or less, and more preferably 50 parts by mass or less, per 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other polyolefin polymer, and the filler.

[0125] The other polyolefin polymers can be used alone or in combination of two or more kinds.

[0126] <Filler> The filler is not particularly limited, and examples thereof include organic fillers and inorganic fillers.

[0127] Organic fillers include, for example, natural fibers and starch.

[0128] The natural fibers include at least one selected from the group consisting of wood flour, wood fiber, bamboo, cotton, and cellulose.

[0129] Inorganic fillers include, for example, oxides (e.g., alumina, iron oxide, ferrite, magnesium oxide, titanium oxide, antimony trioxide, zirconium oxide, barium oxide, and calcium oxide), hydroxides (e.g., aluminum hydroxide and magnesium hydroxide), silicates (e.g., aluminum silicate (clay), talc (magnesium silicate), mica, kaolin, calcium silicate, glass fiber, glass flakes, and glass beads), sulfates (e.g., aluminum sulfate, magnesium sulfate, barium sulfate, and calcium sulfate), carbonates (e.g., calcium carbonate, basic magnesium carbonate, and dolomite (CaMg(CO3)2)), nitrides (e.g., aluminum nitride and boron nitride), titanates (e.g., barium titanate and potassium titanate), metals (iron, cobalt, silver, gold, copper, and alloys thereof), sedimentary rock-based fillers (e.g., diatomaceous earth and limestone), and silicon carbide.

[0130] As the filler, from the viewpoint of improving the mechanical strength of the resin composition, preferably, at least one selected from the group consisting of natural fibers, talc, calcium carbonate, and starch is selected.

[0131] More preferably, the filler is a natural fiber, and even more preferably, the filler is cellulose.

[0132] From the viewpoint of achieving both mechanical strength and dispersibility, the content of the filler is, for example, 0.1 parts by mass or more, preferably 30 parts by mass or more, and for example, 70 parts by mass or less, per 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other polyolefin polymer, and the filler.

[0133] The fillers can be used alone or in combination of two or more kinds.

[0134] <Additives> The resin composition contains additives in appropriate proportions as necessary.

[0135] Examples of additives include impact resistance modifiers, flame retardants, flame retardant assistants, heat stabilizers, antioxidants, heat resistance agents, weather resistance agents, light stabilizers, release agents, flow modifiers, colorants, lubricants, antistatic agents, crystal nucleating agents, plasticizers, and foaming agents.

[0136] The additives can be used alone or in combination of two or more kinds.

[0137] <Preparation of Resin Composition> The resin composition is prepared by melt-kneading the acid-modified polyolefin wax, other polyolefin polymers, a filler, and additives which are added as required.

[0138] As for the melt kneading conditions, the kneading temperature is, for example, 150° C. or more and, for example, 220° C. or less. The kneading time is, for example, 1 minute or more and, for example, 60 minutes or less, preferably 20 minutes or less.

[0139] The resin composition is then molded into a molded article by, for example, a known molding method (for example, injection molding, blow molding, inflation molding, cast film molding, extrusion molding, and compression molding).

[0140] Such molded articles are suitable for use in a wide range of fields (for example, household products and industrial products).

[0141] <Action and effect> The polyolefin wax has a specific weight average molecular weight and a specific softening point, which can improve the handling property and mechanical strength.

[0142] Specifically, the polypropylene wax (Example 8) in Patent Document 1 has a melt viscosity of 1500 mPa·s and a softening point of 131°C.

[0143] On the other hand, the melt viscosity (170° C.) and weight average molecular weight of commercially available polypropylene waxes are summarized in Table 1 and FIG.

[0144] [Table 1]

[0145] FIG. 1 shows that the melt viscosity (170° C.) and the weight average molecular weight are in a proportional relationship (weight average molecular weight=10408×ln(melt viscosity)−37829).

[0146] When the melt viscosity is 1,500 mPa·s, the weight average molecular weight is found to be approximately 38,000.

[0147] In other words, since the weight average molecular weight of the polypropylene wax in Patent Document 1 is large, when an acid-modified polyolefin wax obtained using this polypropylene wax is added to a resin composition, there is a problem that the fluidity decreases and the handleability decreases.

[0148] On the other hand, the weight average molecular weight of this polyolefin wax is 25000 or less. Therefore, when the acid-modified polyolefin wax obtained by using this polyolefin wax is added to a resin composition, the decrease in fluidity can be suppressed. As a result, the handleability can be improved.

[0149] Moreover, the weight average molecular weight of the polyolefin wax is not less than 1000. Therefore, when an acid-modified polyolefin wax obtained by using this polyolefin wax is added to a resin composition, the mechanical strength can be improved.

[0150] In addition, the softening point of this polyolefin wax is not less than 110° C. Therefore, when an acid-modified polyolefin wax obtained by using this polyolefin wax is added to a resin composition, the mechanical strength can be improved.

[0151] In addition, the softening point of this polyolefin wax is not higher than 155° C. Therefore, when the acid-modified polyolefin wax obtained using this polyolefin wax is added to a resin composition, it has excellent handleability.

[0152] That is, by adjusting the weight average molecular weight and softening point of the polyolefin wax to fall within a predetermined range, it is possible to achieve both ease of handling and mechanical strength. EXAMPLES

[0153] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. Note that "parts" and "%" are based on mass unless otherwise specified. In addition, the specific numerical values ​​of the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit value (numerical value defined as "less than or equal to" or "less than") or lower limit value (numerical value defined as "more than or equal to" or "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Form for carrying out the invention".

[0154] <Production of polyolefin wax, acid-modified polyolefin wax, and resin composition> Example 1 [Production of polyolefin wax] Olefin polymerization was produced by polymerizing the polymerization components in the presence of an olefin polymerization catalyst. Specifically, using a pressure-resistant reactor (internal volume 100 L) with an agitator equipped with a temperature-controllable jacket, the polymerization components were polymerized by continuously supplying the polymerization components (propylene) and hydrogen to a solvent containing an olefin polymerization catalyst under the polymerization conditions shown in Table 2. The olefin polymerization catalyst used was a transition metal compound of the above general formula (1) and triisobutylaluminum (organoaluminum compound). In this way, a polyolefin wax was produced.

[0155] [Production of acid-modified polyolefin wax] 800g of polyolefin wax was charged into a glass reactor and melted at 170°C under a nitrogen atmosphere. Next, 42g of maleic anhydride and 8.8g of radical polymerization initiator were continuously fed into the reaction system (temperature 170°C) over 5 hours. After heating and reacting for 1 hour, the wax was degassed in a vacuum of 10mmHg for 0.5 hours while still in the molten state to remove volatiles. The reaction product was then cooled to obtain an acid-modified polypropylene wax.

[0156] [Production of resin composition] 3 parts by mass of acid-modified polypropylene wax, other polypropylene polymer (propylene-based polymer (PP manufactured by Prime Polymer Co., Ltd. (product name Prime Polypro J137G, MFR (230°C, 2.16 kg) = 30 g / 10 min, density 910 kg / m 3 A resin composition was obtained by melt-kneading 47 parts by mass of cellulose fibers (powdered cellulose (product name KC Flock W-100GK, average particle size 37 μm, manufactured by Nippon Paper Industries Co., Ltd.)) and 50 parts by mass of cellulose fibers (powdered cellulose (product name KC Flock W-100GK, average particle size 37 μm, manufactured by Nippon Paper Industries Co., Ltd.)) at a kneading temperature of 190° C., a screw rotation speed of 50 rpm, and a kneading time of 10 minutes using a Labo Plastomill (Toyo Seiki Seisakusho Co., Ltd.).

[0157] Examples 2 to 4 and Comparative Example 1 A polyolefin wax was produced in the same manner as in Example 1 under the polymerization conditions shown in Table 2. Thereafter, an acid-modified polyolefin wax and a resin composition were produced in the same manner as in Example 1.

[0158] Comparative Example 2 A resin composition was produced in the same manner as in Example 1, except that the acid-modified polypropylene wax was not added and the amount of the other polypropylene polymer was changed to 50 parts by mass during the production of the resin composition.

[0159] <Evaluation> [Structural units derived from propylene and structural units derived from ethylene] For the polyolefin waxes of each Example and Comparative Example, a Fourier transform infrared spectrophotometer FT / IR-610 manufactured by JASCO Corporation was used to measure the horizontal vibration of 1155 cm due to the methyl group of propylene. -1 Area around 4325cm and overtone absorption due to CH stretching vibration -1 The absorbance around the ethylene-derived structural unit was measured, and the content of the ethylene-derived structural unit in the polyolefin wax was calculated from the ratio of the absorbance and the calibration curve. The content of the propylene-derived structural unit was calculated from the content of the ethylene-derived structural unit obtained. 13 The results are shown in Table 2.

[0160] [Melting point and heat of fusion] The melting point and heat of fusion of the polyolefin wax in each Example and Comparative Example were measured using a Diamond DSC manufactured by PerkinElmer, Inc. Specifically, the polyolefin wax was melted at 200°C and formed into a sheet, and then about 5 mg of the sheet-shaped sample was filled into an Al sample pan to prepare the sample.

[0161] Next, the sample was heated to 230°C at 10°C / min under a nitrogen atmosphere and held for 10 minutes, then cooled to -40°C at 10°C / min and held for 5 minutes. Next, the sample was heated to 200°C at 10°C / min under a nitrogen atmosphere. The melting point was calculated from the peak apex of the crystal melting peak observed at this time. The heat of fusion was also calculated from the area of ​​the crystal melting peak. The results are shown in Table 2.

[0162] [Softening point] The softening points of the polyolefin wax and acid-modified polyolefin wax in each of the Examples and Comparative Examples were measured in accordance with JIS K2207. The results are shown in Table 2.

[0163] [Tacticity (mesopentad fraction)] The stereoregularity (mesopentad fraction) of the polyolefin wax in each example is 13 The calculation was performed using C-NMR spectrum. 13 C-NMR spectrum was measured by dissolving 60 mg of sample in 0.6 ml of a 4 / 1 mixed solvent of o-dichlorobenzene and deuterated benzene (o-dichlorobenzene / deuterated benzene; volume ratio) using a Bruker Biospin AVANCE III cryo-500 nuclear magnetic resonance spectrometer at 120 °C, 45° pulse, repetition time 25 seconds, and accumulation number 64 times. The reference value of the chemical shift was set to 21.59 ppm for the signal derived from the mmmm of the methyl group. The assignment of each peak was performed according to the usual method, and the stereoregularity (mesopentad fraction) was determined by the ratio of each peak area. The results are shown in Table 2.

[0164] [Weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight dispersity (Mw / Mn)] The weight average molecular weight (Mw) of the polyolefin wax and the acid-modified polyolefin wax of each Example and Comparative Example was determined. Specifically, GPC measurement was performed under the following conditions, and the weight average molecular weight (Mw) was determined from a calibration curve using a commercially available monodisperse standard polystyrene. The results are shown in Table 2. {conditions} Equipment: Gel permeation chromatograph Alliance GPC2000 (Waters) Solvent: o-dichlorobenzene Column: TSKgel GMH6-HT x 2, TSKgel GMH6-HTL column x 2 (both manufactured by Tosoh Corporation) Flow rate: 1.0ml / min Sample: 0.15mg / mL o-dichlorobenzene solution Column temperature: 140℃ Injection volume: 400μl Detector: Differential refractometer

[0165] [Acid value] The acid value of the acid-modified polyolefin wax of each Example was measured in accordance with JIS K5902. The results are shown in Table 2.

[0166] [Tensile modulus] The resin compositions of each Example and Comparative Example were pressed into sheets using a press molding machine (AYSR-5 type tabletop test press machine manufactured by Shinto Metal Industries Co., Ltd.) under conditions of heating temperature 210°C, cooling temperature 20°C, heating time 10 minutes, cooling time 4 minutes, and pressure 5 MPa, and then punched out with a dumbbell cutter to prepare test specimens. The shape of the test specimens was in accordance with ASTM D638 No. 4 dumbbell shape.

[0167] Using the prepared test pieces, tensile tests were carried out based on ASTM D638 under conditions of a chuck distance of 64 mm and a test speed of 50 mm / min to measure the tensile modulus of elasticity. The results are shown in Table 2.

[0168] [Mixing torque (handling)] The resin compositions of each Example and Comparative Example were kneaded in a Labo Plastomill, and the kneading torque was measured 30 times for one minute just before the end of kneading, and the average value was calculated. The results are shown in Table 2.

[0169] <Consideration> The polypropylene waxes of Examples 1 to 4 have a weight average molecular weight (Mw) of 1000 or more and 25000 or less, and a softening point of 110° C. or more and 155° C. or less, and therefore it is understood that both the handleability and the mechanical strength can be improved.

[0170] On the other hand, the weight average molecular weight (Mw) of the polypropylene wax of Comparative Example 1 exceeds 25,000. Therefore, it is understood that the handleability is deteriorated.

[0171] FIG. 2 shows the relationship between the weight average molecular weight and the softening point of the polyolefin waxes of the respective Examples and Comparative Examples.

[0172] The polypropylene waxes of Examples 1 to 4 have a weight average molecular weight (Mw) of 1000 or more and 25000 or less (1000≦Mw≦25000), a softening point of 110° C. or more and 155° C. or less (110≦softening point≦155), and satisfy the above relational formula (1) (shaded area in FIG. 2). Therefore, it is understood that the polypropylene waxes of Examples 1 to 4 can achieve both handleability and mechanical strength.

[0173] [Table 2]

Claims

1. Propylene homopolymer, or A copolymer of propylene and ethylene or an α-olefin having 4 or more carbon atoms, The weight average molecular weight (Mw) is 1,000 or more and 25,000 or less, A polypropylene wax having a softening point of 110°C or higher and 155°C or lower.

2. The polypropylene wax according to claim 1, having a molecular weight dispersity (Mw / Mn) of 1.5 or more and 2.5 or less.

3. The polypropylene wax according to claim 1, wherein the melting point is 100°C or higher and 155°C or lower.

4. The polypropylene wax according to claim 1, wherein the softening point and the weight average molecular weight (Mw) satisfy the following formula (1): Softening point≧0.00209×Mw+90 (1)

5. The polypropylene wax according to claim 1, wherein the weight average molecular weight (Mw) is 5,000 or more and 20,000 or less.

6. The polypropylene wax according to claim 1, wherein the melting point is 120°C or higher and 150°C or lower.

7. The polypropylene wax according to any one of claims 1 to 6, wherein the structural units derived from propylene are 98 mol % or more.

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