Acid-modified polyolefin wax and resin composition

Abstract

To provide a polyolefin wax with excellent dispersibility and mechanical strength, even when used in small amounts, and a resin composition comprising the polyolefin wax.SOLUTION: An acid-modified polyolefin wax comprises an acid-modified olefinic polymer. The acid-modified olefinic polymer is an olefinic polymer modified with a maleic anhydride. The acid-modified olefinic polymer has a weight average molecular weight of 18000 or more and 70000 or less. The acid-modified olefinic polymer has an acid value of 80 mgKOH / g or more and 150 mgKOH / g or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an acid-modified polyolefin wax and a resin composition. [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] As an acid-modified polyolefin wax, for example, a wax (acid value: 59 mgKOH / g) obtained by modifying a polypropylene wax with maleic anhydride has been proposed (see, for example, Example 5 of Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Publication No. 2001-504542 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, if the blending ratio of the acid-modified polyolefin wax to the resin composition is increased, bleeding occurs. However, if the blending amount of the acid-modified polyolefin wax is reduced from the viewpoint of suppressing bleeding, dispersibility decreases. In other words, there is a trade-off between suppression of bleeding and dispersibility.

[0006] In response to this, it is required to improve the dispersibility even when the amount of the acid-modified polyolefin wax blended is small, and to achieve this, it has been considered to increase the acid value of the acid-modified polyolefin wax.

[0007] On the other hand, the acid value of the wax in Patent Document 1 is only 59 mgKOH / g, which means that dispersibility cannot be sufficiently improved.

[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 has excellent dispersibility and excellent mechanical strength even when incorporated in a small amount, and a resin composition containing the polyolefin wax. [Means for solving the problem]

[0010] The present invention [1] is an acid-modified polyolefin wax comprising an acid-modified olefin polymer, the acid-modified olefin polymer being an olefin polymer modified with maleic anhydride, the weight-average molecular weight of the acid-modified olefin polymer being 18,000 or more and 70,000 or less, and the acid value of the acid-modified olefin polymer being 80 mgKOH / g or more and 150 mgKOH / g or less.

[0011] The present invention [2] includes the acid-modified polyolefin wax according to the above [1], wherein the olefin polymer is at least one selected from the group consisting of a propylene homopolymer, a copolymer of ethylene and 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.

[0012] The present invention [3] includes the acid-modified polyolefin wax according to the above [1] or [2], in which the weight average molecular weight (Mw) and the acid value (A) satisfy the following relational formula (1): A(mgKOH / g)≧6.48×ln(Mw)+16 (1)

[0013] The present invention [4] comprises the acid-modified polyolefin wax according to any one of the above [1] to [3], wherein the softening point of the acid-modified olefin polymer, as measured according to JIS K2207, is 70°C or higher and 160°C or lower.

[0014] The present invention [5] includes the acid-modified polyolefin wax according to any one of [1] to [4] above, another olefin polymer, and a filler, and the content of the acid-modified polyolefin wax is 0.1 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other olefin polymer, and the filler, the content of the other olefin polymer is 29.9 parts by mass or more and 99.8 parts by mass or less relative to 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other olefin polymer, and the filler, and the content of the filler is 0.1 parts by mass or more and 70 parts by mass or less relative to 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other olefin polymer, and the filler.

[0015] The present invention [6] includes the resin composition according to the above [5], wherein the filler is at least one selected from the group consisting of natural fibers, talc, calcium carbonate, and starch.

[0016] The present invention [7] includes the resin composition described in [6] above, in which the natural fiber is at least one selected from the group consisting of wood flour, wood fiber, bamboo, cotton, and cellulose. Effect of the Invention

[0017] In the acid-modified polyolefin wax of the present invention, the acid value of the acid-modified olefin polymer is 80 mgKOH / g or more and 150 mgKOH / g or less. Therefore, when this acid-modified polyolefin wax is blended with a resin composition containing a filler, the wax has excellent dispersibility even when the blending amount is small.

[0018] The weight average molecular weight of the acid-modified olefin polymer is from 18000 to 70000. Therefore, the mechanical strength and handling properties are excellent.

[0019] The resin composition of the present invention contains the acid-modified polyolefin wax of the present invention, and therefore has excellent dispersibility, mechanical strength and handleability. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a graph showing the relationship between the weight average molecular weight and the acid value of the acid-modified olefin polymers of each Production Example and each Production Comparative Example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] 1. Acid-modified polyolefin wax The acid-modified polyolefin wax contains an acid-modified olefin polymer, and is preferably made of an acid-modified olefin polymer.

[0022] The acid-modified olefin polymer is a modified product obtained by modifying an olefin polymer with maleic anhydride, specifically, a graft-modified product obtained by modifying an olefin polymer with maleic anhydride.

[0023] <Olefin polymer> An olefin polymer is a polymer of polymerization 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 olefin polymer 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] Specific examples of such olefin polymers include homopolymers of ethylene, copolymers of ethylene and propylene, copolymers of ethylene and an α-olefin having 4 to 12 carbon atoms, homopolymers of propylene, 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.

[0031] In terms of improving mechanical strength when this acid-modified polyolefin wax is blended into a resin composition (described later), the olefin polymer is preferably at least one selected from the group consisting of a propylene homopolymer, a copolymer of ethylene and 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.

[0032] More preferably, the olefin polymer is a copolymer of ethylene and propylene, that is, the polymerization components are more preferably composed of ethylene and propylene.

[0033] When the olefin polymer 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 10 mol% or less, preferably 5 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, and 99.9 mol% or less, preferably 99 mol% or less.

[0034] The olefin polymers can be used alone or in combination of two or more kinds.

[0035] [Production method of olefin polymer] The olefin polymer can be obtained by polymerizing the polymerization components in the presence of an olefin polymerization catalyst.

[0036] The olefin polymerization catalyst comprises a transition metal compound.

[0037] Examples of the transition metal compound include the transition metal compounds listed in WO 2014 / 050816.

[0038] As the transition metal compound, preferably, there is mentioned a transition metal compound represented by the following general formula (1). [ka]

[0039] The olefin polymerization catalyst preferably comprises an organoaluminum compound.

[0040] 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.

[0041] As the organoaluminum compound, preferably, trialkylaluminum is used, and more preferably, triisobutylaluminum is used.

[0042] The organoaluminum compounds can be used alone or in combination of two or more kinds.

[0043] The polymerization method is preferably solution polymerization.

[0044] In solution polymerization, the polymerization components are polymerized in the presence of a solvent (e.g., n-hexane). Preferably, the polymerization components and an olefin polymerization catalyst (a transition metal compound and an organoaluminum compound, if necessary) are continuously fed to the solvent in a reaction vessel to polymerize the polymerization components continuously.

[0045] The supply amount of the solvent is, for example, 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.

[0046] 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.

[0047] The supply amount of the transition metal compound is, for example, 0.040 mmol / hour or more, preferably 0.050 mmol / hour or more, and for example, 0.200 mmol / hour or less, preferably 0.100 mmol / hour or less, more preferably 0.070 mmol / hour or less.

[0048] The supply amount of the organoaluminum compound is, for example, 15 mmol / hour or more, preferably 18 mmol / hour or more, and for example, 30 mmol / hour or less, preferably 20 mmol / hour or less.

[0049] 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, or even 300 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, or even 500 or less.

[0050] 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, and particularly preferably 120°C or less.

[0051] 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.

[0052] In this method, hydrogen is supplied from the viewpoint of adjusting the molecular weight, and the weight average molecular weight of the olefin polymer can be reduced by supplying hydrogen.

[0053] The amount of hydrogen supplied is, for example, 0.05 NL / hour or more, preferably 1 NL / hour or more, more preferably 5 NL / hour or more, even more preferably 10 NL / hour or more, particularly preferably 15 NL / hour or more, and for example, 50 NL / hour or less, preferably 30 NL / hour or less, 20 NL / hour or less.

[0054] The amount of the olefin polymer taken out is, for example, 0.5 kg / hour or more and, for example, 5.0 kg / hour or less, preferably 2.0 kg / hour or less.

[0055] In this way, an olefin polymer is produced.

[0056] The viscosity average molecular weight (Mv) of the olefin polymer is, for example, 15,000 or more, preferably 18,000 or more, and for example, 30,000 or less, preferably 20,000 or less.

[0057] The weight average molecular weight of the olefin polymer is, for example, 20,000 or more, preferably 25,000 or more, and for example, 40,000 or less, preferably 30,000 or less.

[0058] When the weight average molecular weight of the olefin polymer is within the above range, the weight average molecular weight of the acid-modified olefin polymer described below can be adjusted to a predetermined range.

[0059] The weight average molecular weight is a polystyrene-equivalent molecular weight determined by gel permeation chromatography (GPC) (the same applies hereinafter).

[0060] The number average molecular weight of the olefin polymer is, for example, 8,000 or more, preferably 10,000 or more, and for example, 23,000 or less, preferably 17,000 or less.

[0061] The number average molecular weight is a polystyrene-equivalent molecular weight determined by gel permeation chromatography (the same applies below).

[0062] The softening point (JIS K2207) of the olefin polymer is, for example, 70°C or more, preferably 110°C or more, more preferably 120°C or more, even more preferably 130°C or more, and for example, 160°C or less, preferably 155°C or less, more preferably 150°C or less, even more preferably 140°C or less.

[0063] The melt viscosity (180° C.) of the olefin polymer is, for example, 300 mPa·s or more, preferably 400 mPa·s or more, more preferably 500 mPa·s or more, and for example, 700 mPa·s or less, preferably 600 mPa·s or less.

[0064] The method for measuring the melt viscosity will be described in detail in the Examples below (the same applies hereinafter).

[0065] <Method of producing acid-modified olefin polymer> The acid-modified olefin polymer can be obtained by modifying an olefin polymer with maleic anhydride.

[0066] Specifically, first, the olefin polymer is melted at, for example, 100°C or higher, preferably 150°C or higher, and, for example, 180°C or lower.

[0067] Then, maleic anhydride and a radical polymerization initiator are added, heated and stirred.

[0068] The mixing ratio of maleic anhydride is, for example, 8 parts by mass or more, preferably 10 parts by mass or more, and for example, 20 parts by mass or less, preferably 15 parts by mass or less, per 100 parts by mass of the olefin polymer, from the viewpoint of setting the acid value (described later) of the acid-modified olefin polymer within a predetermined range.

[0069] The radical polymerization initiator may, for example, be an organic peroxide (eg, di-tert-butyl peroxide).

[0070] The mixing ratio of the radical polymerization initiator relative to 100 parts by mass of the olefin polymer is, for example, 1 part by mass or more, preferably 2 parts by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass or less.

[0071] The radical polymerization initiators can be used alone or in combination of two or more kinds.

[0072] 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.

[0073] In this way, an acid-modified olefin polymer is produced.

[0074] The viscosity average molecular weight (Mv) of the olefin polymer is, for example, 10,000 or more, preferably 12,000 or more, and for example, 20,000 or less, preferably 15,000 or less.

[0075] The weight average molecular weight of the acid-modified olefin polymer is 18,000 or more, preferably 19,000 or more, and for example, 70,000 or less, preferably 60,000 or less, more preferably 50,000 or less.

[0076] When the weight average molecular weight of the acid-modified olefin polymer is equal to or higher than the above lower limit, the mechanical strength can be improved when the acid-modified polyolefin wax is blended with a resin composition (described later).

[0077] On the other hand, if the weight average molecular weight of the acid-modified olefin polymer is less than the above lower limit, the mechanical strength decreases when this acid-modified polyolefin wax is blended with a resin composition (described later).

[0078] In addition, when the weight average molecular weight of the acid-modified olefin polymer 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 handleability is excellent.

[0079] On the other hand, if the weight average molecular weight of the acid-modified olefin polymer exceeds the above upper limit, the viscosity of the acid-modified polyolefin wax becomes excessively high, resulting in poor handleability.

[0080] The acid value (JIS K5902) of the acid-modified olefin polymer is 80 mgKOH / g or more, preferably 85 mgKOH / g or more, and 150 mgKOH / g or less, preferably 120 mgKOH / g or less, more preferably 100 mgKOH / g or less, and even more preferably 90 mgKOH / g or less.

[0081] If the acid value of the acid-modified olefin polymer is equal to or higher than the above lower limit, when an acid-modified polyolefin wax containing this acid-modified olefin polymer is blended with a resin composition containing a filler (described later), the filler dispersibility and mechanical strength are excellent even if the blending amount is small.

[0082] On the other hand, if the acid value of the acid-modified olefin polymer is less than the lower limit, when an acid-modified polyolefin wax containing this acid-modified olefin polymer is blended into a resin composition containing a filler (described later), if the blending amount is small, the filler dispersibility and mechanical strength will decrease.

[0083] In addition, if the acid value of the acid-modified olefin polymer 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 becoming excessively high, resulting in excellent handleability.

[0084] On the other hand, if the acid value of the acid-modified olefin polymer exceeds the above upper limit, the interaction with the filler (described later) becomes too strong, resulting in an excessively high viscosity and poor handleability.

[0085] That is, by adjusting the weight average molecular weight and acid value of the acid-modified olefin polymer to fall within a predetermined range, it is possible to improve dispersibility, mechanical strength and handleability.

[0086] Moreover, the weight average molecular weight (Mw) and the acid value (A) preferably satisfy the following relational expression (1). A(mgKOH / g)≧6.48×ln(Mw)+16 (1)

[0087] If the weight average molecular weight (Mw) and the acid value (A) satisfy the above relational formula (1), it is possible to achieve both a weight average molecular weight that satisfies mechanical strength and handleability, and an acid value that satisfies dispersibility, as will be described in detail later. In detail, it is presumed that when the weight average molecular weight is large, the acid value tends to be high because there are many reaction points of the radical polymerization initiator and maleic anhydride in the polymer chain, and reaction with other polymer chains is less likely to occur after radicals are extracted from the polymer chain (the number of polymer chains is smaller than in low molecular weight products).

[0088] Preferably, from the viewpoint of further achieving a balance between a weight average molecular weight that satisfies mechanical strength and handleability, and an acid value that satisfies dispersibility, the weight average molecular weight (Mw) and the acid value (A) preferably satisfy the following relational formula (2). A(mgKOH / g)≧0.00001×(Mw)+82.5(2)

[0089] The number average molecular weight of the acid-modified olefin polymer is, for example, 4,000 or more, preferably 6,000 or more, and for example, 20,000 or less, preferably 10,000 or less.

[0090] The molecular weight distribution polydispersity (Mw / Mn) of the acid-modified olefin polymer 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.

[0091] The softening point (JIS K2207) of the acid-modified olefin polymer is, for example, 70°C or more, preferably 110°C or more, more preferably 120°C or more, even more preferably 130°C or more, and for example, 160°C or less, preferably 155°C or less, more preferably 150°C or less, even more preferably 140°C or less.

[0092] When the softening point of the acid-modified olefin polymer is equal to or higher than the above lower limit, the heat resistance and mechanical strength can be improved.

[0093] Furthermore, when the softening point of the acid-modified olefin polymer is equal to or lower than the above upper limit, in the production of the resin composition described later, the acid-modified olefin polymer melts earlier than other olefin polymers (described later), making it easier to coat the surface of the filler, and improving dispersibility.

[0094] The melt viscosity (180°C) of the acid-modified olefin polymer is, for example, 300 mPa·s or more, preferably 400 mPa·s or more, more preferably 500 mPa·s or more, even more preferably 550 mPa·s or more, and for example, 1500 mPa·s or less, preferably 1200 mPa·s or less.

[0095] The acid-modified polyolefin wax contains the above-mentioned acid-modified olefin polymer. Therefore, when the acid-modified polyolefin wax is blended into a resin composition containing a filler, the wax has excellent dispersibility even when the blending amount is small. In addition, the wax can have improved mechanical strength and handling properties.

[0096] 2.Resin composition The resin composition contains an acid-modified polyolefin wax, another olefin polymer, and a filler.

[0097] <Acid-modified polyolefin wax> The acid-modified polyolefin wax is a dispersant for the filler.

[0098] The content of the acid-modified polyolefin wax is, relative to 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other olefin polymer, and the filler, 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 15 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 2 parts by mass or less.

[0099] When the content of the acid-modified polyolefin wax is equal to or higher than the above lower limit, the dispersibility of the filler can be reliably improved.

[0100] In addition, when the content of the acid-modified polyolefin wax is equal to or less than the upper limit, the occurrence of bleeding can be suppressed.

[0101] <Other olefin polymers> The other olefin polymer is the base polymer in the resin composition.

[0102] Examples of the other olefin 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 olefin polymer is a homopolymer of propylene.

[0103] The other olefin polymer can be obtained, for example, by the method described in International Publication WO 2004 / 87775. Specifically, the other olefin 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.

[0104] The content ratio of the other olefin 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, per 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other olefin polymer, and the filler, and is, 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.

[0105] The other olefin polymers can be used alone or in combination of two or more kinds.

[0106] <Filler> The filler is not particularly limited, and examples thereof include organic fillers and inorganic fillers.

[0107] Organic fillers include, for example, natural fibers and starch.

[0108] The natural fibers include at least one selected from the group consisting of wood flour, wood fiber, bamboo, cotton, and cellulose.

[0109] 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.

[0110] 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.

[0111] More preferably, the filler is a natural fiber, and even more preferably, the filler is cellulose.

[0112] 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 olefin polymer, and the filler.

[0113] The fillers can be used alone or in combination of two or more kinds.

[0114] <Additives> The resin composition contains additives in appropriate proportions as necessary.

[0115] 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.

[0116] The additives can be used alone or in combination of two or more kinds.

[0117] <Preparation of Resin Composition> The resin composition is prepared by melt-kneading the acid-modified polyolefin wax, other olefin polymers, a filler, and additives which are added as required.

[0118] 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).

[0119] Such molded articles are suitable for use in a wide range of fields (for example, household products and industrial products).

[0120] 3. Effects In the acid-modified polyolefin wax, the acid value of the acid-modified olefin polymer is 80 mgKOH / g or more and 150 mgKOH / g or less. Therefore, when the acid-modified polyolefin wax containing this acid-modified olefin polymer is blended with a resin composition containing a filler, the wax has excellent dispersibility even when the blending amount is small.

[0121] The weight average molecular weight of the acid-modified olefin polymer is from 18000 to 70000. Therefore, the mechanical strength and handling properties are excellent.

[0122] Specifically, 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.

[0123] On the other hand, if the blending ratio of the acid-modified polyolefin wax to the resin composition is increased, bleeding occurs. However, if the blending amount of the acid-modified polyolefin wax is reduced from the viewpoint of suppressing bleeding, dispersibility decreases. In other words, there is a trade-off between suppression of bleeding and dispersibility.

[0124] In response to this, it is required to improve the dispersibility even when the amount of the acid-modified polyolefin wax blended is small, and to achieve this, it has been considered to increase the acid value of the acid-modified polyolefin wax.

[0125] Meanwhile, the olefin polymer that is the raw material of the acid-modified polyolefin wax is usually produced by polymerizing an olefin monomer or by pyrolyzing a polyolefin resin.

[0126] In Patent Document 1, polypropylene wax, which is a raw material for wax (acid-modified polyolefin wax), is produced by polymerizing olefin monomers. Specifically, polypropylene wax is polymerized by a slurry polymerization method, and it is presumed that such polypropylene wax undergoes polymerization with a disordered bond type (i.e., head-to-head bond), so when modified with maleic anhydride, decomposition is likely to occur starting from the head-to-head bond. Therefore, even if the amount of maleic anhydride is increased to increase the acid value, decomposition occurs, and the acid value cannot be increased according to the amount of maleic anhydride. Therefore, there is a problem that dispersibility cannot be improved. In addition, there is a problem that the mechanical strength is reduced because the weight average molecular weight is reduced due to the decomposition.

[0127] On the other hand, the use of olefin polymers produced by pyrolyzing polyolefin resins has also been considered. However, when such olefin polymers are modified with a large amount of maleic anhydride, crosslinking occurs, causing the weight-average molecular weight (viscosity) to become excessively high, which reduces the ease of handling.

[0128] In contrast, the acid-modified olefin polymer of the present invention is presumed to be polymerized without any disorder in the bond type (i.e., head-to-tail bond). Therefore, in this acid-modified polyolefin wax, the acid-modified olefin polymer is an acid-modified olefin polymer that can increase the acid value according to the amount of maleic anhydride and does not excessively increase or decrease the weight average molecular weight. Such an acid-modified olefin polymer is preferably an acid-modified olefin polymer that satisfies the above relational formula (1). With an acid-modified polyolefin wax containing such an acid-modified olefin polymer, it is possible to achieve both a weight average molecular weight that satisfies mechanical strength and handleability and an acid value that satisfies dispersibility.

[0129] In addition, the decomposition can be prevented from lowering the weight average molecular weight, which improves the mechanical properties. In addition, the crosslinking can be prevented from excessively increasing the weight average molecular weight, which improves the ease of handling.

[0130] In addition, so long as the acid-modified olefin polymer is polymerized without any disorder in the bond type (that is, head-to-tail bond), the polymerization method is not limited.

[0131] The resin composition contains the acid-modified polyolefin wax, and therefore has excellent dispersibility, mechanical strength and handleability. EXAMPLES

[0132] 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".

[0133] <Production of Olefin Polymer> Preparation Example 1 and Preparation Example 2 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 (n-hexane) containing an olefin polymerization catalyst under the polymerization conditions shown in Table 1. The olefin polymerization catalyst used was a transition metal compound of the above general formula (1) and triisobutylaluminum (organoaluminum compound). As a result, a propylene homopolymer (olefin polymer) was produced.

[0134] Preparation Example 3 Polypropylene resin (product name: Prime Polypro J707G, MFR 30g / 10min, density 910kg / m 3An olefin polymer was produced by heating the resulting polymer (manufactured by Prime Polymer Co., Ltd.) at 380° C. for 3 hours in a nitrogen atmosphere.

[0135] [Table 1]

[0136] <Production of acid-modified olefin polymer (acid-modified polyolefin wax)> Production Example 1, Production Example 2, Production Comparative Examples 1 to 6 Based on the recipe shown in Table 2, an olefin polymer was charged into a glass reactor and melted at 170°C under a nitrogen atmosphere. Next, maleic anhydride and a radical polymerization initiator were continuously fed into the reaction system (temperature 170°C) over 5 hours. After heating and reacting for 1 hour, the mixture was degassed in a vacuum of 10 mmHg for 0.5 hours while still in the molten state to remove volatiles. The reaction product was then cooled to obtain an acid-modified olefin polymer (acid-modified polyolefin wax).

[0137] In Production Example 2, the temperature at which maleic anhydride and the radical polymerization initiator were reacted was changed to 167° C. In Production Comparative Example 6, the viscosity of the reaction product increased continuously during the reaction, making stirring difficult, and the reaction was therefore stopped.

[0138] [Table 2]

[0139] <Production of Resin Composition> Example 1, Example 2, and Comparative Examples 1 to 4 The acid-modified polyolefin wax, other olefin polymers, and a filler (powdered cellulose) were melt-kneaded using a co-rotating twin-screw extruder (manufactured by Parker Corporation, φ25 mm, L / D=41) under conditions of a cylinder temperature of 210°C, a discharge rate of 3 kg / hour, and a screw rotation speed of 150 rpm, and then pelletized to obtain a resin composition.

[0140] In Table 3, details of each component are as follows. 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 , Nippon Paper Industries Co., Ltd. Cellulose: Powdered cellulose (product name KC Flock W-100GK, average particle size 37 μm, manufactured by Nippon Paper Industries Co., Ltd.)

[0141] <Evaluation> [Weight average molecular weight (Mw)] The weight average molecular weight (Mw) of the olefin polymer of each preparation example, the acid-modified olefin polymer of each production example and each production 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 Tables 1 and 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

[0142] [Softening point] The softening points of the olefin polymers of each Preparation Example, and the acid-modified olefin polymers of each Production Example and each Production Comparative Example were measured in accordance with JIS K2207. The results are shown in Tables 1 and 2.

[0143] [Melt Viscosity] The olefin polymers of each Preparation Example, the acid-modified olefin polymers of each Production Example and each Production Comparative Example were heated to 180°C and melted to prepare samples. The melt viscosity of the samples was measured using a Brookfield viscometer. The results are shown in Tables 1 and 2.

[0144] [Acid value] The acid value of the acid-modified olefin polymer of each Production Example and each Production Comparative Example was measured in accordance with JIS K5902. The results are shown in Tables 1 and 2.

[0145] [Mechanical strength] (Resin pressure) The resin pressure at the die when the resin compositions of each Example and Comparative Example were kneaded in a twin-screw extruder was measured once per minute, and this measurement was continued for 30 minutes (30 times), and the average value was calculated. The results are shown in Table 3.

[0146] (tensile strength, tensile modulus and tensile elongation) The resin composition (pellets) of each Example and Comparative Example was dried at 100° C. for 3 hours, and then injection molded using an injection molding machine (Niigata NN100, manufactured by Niigata Machine Techno Co., Ltd.) under conditions of a cylinder temperature of 210° C. and a mold temperature of 40° C. to prepare a test specimen. The shape of the test specimen was based on JIS K7161.

[0147] Then, using the injection-molded test pieces (ISO universal test pieces), tensile tests were carried out based on JIS K7161 under conditions of a chuck distance of 115 mm and a test speed of 50 mm / min, and the tensile strength, tensile modulus and tensile elongation were measured.

[0148] [Dispersibility] The core phase (resin flow direction) cross section of the injection molded pieces of the resin compositions of each Example and Comparative Example was observed at 500x magnification using a scanning electron microscope (SEM). Specifically, the interface adhesion between the cellulose fiber and other olefin polymers was observed. The dispersibility was evaluated based on the following criteria. The results are shown in Table 3. {standard} ○: 90% or more of the entire interface was in contact. △: 80% or more but less than 90% of the entire interface was in contact. ×: Less than 80% of the entire interface was in contact. In the above criteria, the order of ◯, △, and × indicates that the impact of deterioration of dispersibility due to a decrease in kneading strength and a decrease in the amount of dispersing agent added on quality (appearance / physical properties) increases.

[0149] <Consideration> The relationship between the weight average molecular weight and the acid value of the acid-modified olefin polymers of each Production Example and each Production Comparative Example is shown in FIG.

[0150] In Production Example 1, the weight average molecular weight of the acid-modified olefin polymer is 18,000 or more and 70,000 or less (18,000≦Mw≦70,000), and the acid value of the acid-modified olefin polymer is 80 mgKOH / g or more and 150 mgKOH / g or less (80≦A≦150), and therefore, it is found that the acid-modified olefin polymer of Production Example 1 can achieve both a weight average molecular weight that satisfies mechanical strength and handleability and an acid value that satisfies dispersibility.

[0151] Moreover, in Example 1 and Example 2, the same acid-modified polyolefin wax is used, but the blending amount is different.

[0152] Example 2, which contains a small amount of the compound, has the same degree of dispersibility as Example 1, which contains a large amount of the compound. This shows that even if the amount of the compound is small, the dispersibility is excellent.

[0153] [Table 3]

Claims

1. Contains an acid-modified olefin polymer, The acid-modified olefin polymer is an olefin polymer modified with maleic anhydride, The weight average molecular weight of the acid-modified olefin polymer is 18,000 or more and 70,000 or less, The acid-modified polyolefin wax, wherein the acid value of the acid-modified olefin polymer is 80 mgKOH / g or more and 150 mgKOH / g or less.

2. The acid-modified polyolefin wax according to claim 1, wherein the olefin polymer is at least one selected from the group consisting of a propylene homopolymer, a copolymer of ethylene and propylene, a copolymer of propylene and an α-olefin having from 4 to 12 carbon atoms, and a copolymer of ethylene, propylene and an α-olefin having from 4 to 12 carbon atoms.

3. The acid-modified polyolefin wax according to claim 1, wherein the weight average molecular weight (Mw) and the acid value (A) satisfy the following relational expression (1): A (mgKOH / g)≧6.48×ln(Mw)+16 (1)

4. The acid-modified polyolefin wax according to claim 1, wherein the acid-modified olefin polymer has a softening point of 70° C. or more and 160° C. or less as measured in accordance with JIS K2207.

5. The acid-modified polyolefin wax according to any one of claims 1 to 4, another olefin polymer, and a filler, the content ratio of the acid-modified polyolefin wax is 0.1 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other olefin polymer, and the filler, the content ratio of the other olefin polymer is 29.9 parts by mass or more and 99.8 parts by mass or less with respect to 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other olefin polymer, and the filler, A resin composition comprising the acid-modified polyolefin wax, the other olefin polymer, and the filler in a content ratio of 0.1 parts by mass or more and 70 parts by mass or less, based on 100 parts by mass of the total amount of the acid-modified polyolefin wax, the other olefin polymer, and the filler.

6. The resin composition according to claim 5, wherein the filler is at least one selected from the group consisting of natural fibers, talc, calcium carbonate and starch.

7. The resin composition according to claim 6, wherein the natural fiber is at least one selected from the group consisting of wood flour, wood fiber, bamboo, cotton, and cellulose.

Images