Modified polyolefin resin

Abstract

To provide a resin filler dispersant that, by being incorporated into a resin composition including a filler such as woody-biomass-derived filler, allows enhancement of filler dispersibility and enables the resulting resin composition to develop high strength.SOLUTION: A modified polyolefin resin for a resin filler dispersant has a melting point of 70-140°C and a graft amount of α,β-unsaturated carboxylic acid and / or a derivative thereof of 4.0-8.0 wt.%, and preferably has an MFR (melt flow rate) of 150-500 g / 10 min when measured at 165°C under a load of 1.2 kg.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a modified polyolefin resin for use as a filler dispersant for resins. [Background technology]

[0002] Biomass materials are attracting attention as industrial resources. Biomass materials refer to materials derived from living organisms such as plants. Because biomass materials are organic, they emit carbon dioxide when burned. However, the carbon contained in them comes from carbon dioxide absorbed from the atmosphere through photosynthesis during the biomass growth process, so even if biomass materials are used and incinerated, the amount of carbon dioxide emitted over their life cycle is less than that of petrochemical products.

[0003] Against the backdrop of global environmental issues such as global warming, there is an urgent need to conserve resources, recycle materials to turn waste into raw materials, and promote environmental circulation cycles such as those typified by biodegradable plastics.In Japan, the revised Recycling Law and the Green Purchasing Law have been established, and there is a growing need for products that comply with these laws.

[0004] In this context, incorporating biomass materials into resin molded products, which are widely used in everything from automotive parts to everyday items, would promote the practice of reducing carbon dioxide emissions throughout their life cycle. For example, Patent Document 1 describes a composite material containing carboxymethylated cellulose nanofibers, a polymer compound having a primary amino group, an acid-modified polyolefin, and a polyolefin. Patent Document 2 describes a cellulose composite material containing wood pulp and a polymer matrix. Patent Document 3 describes a method for producing a wood-flour-containing resin injection-molded product by mixing wood flour and random polypropylene resin and using an injection molding machine. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2014 / 087767 [Patent Document 2] Special Publication No. 2019-512591 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-138337 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when simply mixing "woody biomass" and "thermoplastic resin" and melting them under heat to form them, the hydrophilicity of woody biomass makes it difficult to mix uniformly with the thermoplastic resin, resulting in a problem of weakened strength in the resulting molded article.

[0007] In order to further improve the strength of composites of woody biomass and thermoplastic resins, it is desirable to develop dispersants that improve the dispersibility of woody biomass in thermoplastic resins more than ever before.

[0008] The present invention has been made in view of the above, and aims to provide a filler dispersant for resins that, when blended into a resin composition containing a filler such as woody biomass, can improve the dispersibility of the filler and enable the resin composition to exhibit high strength. [Means for solving the problem]

[0009] The present invention provides the following [1] to [4]. [1] A modified polyolefin resin for use as a filler dispersant for resins, having a melting point of 70 to 140°C and a graft amount of α,β-unsaturated carboxylic acid and / or its derivative of 4.0 to 8.0% by weight. [2] The modified polyolefin resin according to [1], which has an MFR (melt flow rate) of 150 to 500 g / 10 min measured at a measurement temperature of 165° C. and a measurement load of 1.2 kg. [3] The modified polyolefin resin according to [1], which is modified with a (meth)acrylic acid ester. [4] A resin composition comprising the acid-modified polyolefin resin according to [1] and a filler for resin. [Effects of the Invention]

[0010] According to the present invention, by blending a filler such as woody biomass into a resin composition containing the filler, the dispersibility of the filler can be improved, and high strength can be achieved when the resin composition is prepared. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Modified polyolefin resin> The modified polyolefin resin of the present invention has a melting point of 70 to 140° C. and the amount of modification with α,β-unsaturated carboxylic acid and / or derivative thereof is 4.0 to 8.0% by weight.

[0012] (Polyolefin resin) The polyolefin resin is not particularly limited, but preferably contains at least one selected from the group consisting of polypropylene, ethylene-propylene copolymer, propylene-1-butene copolymer, and ethylene-propylene-1-butene copolymer. The polyolefin resin may be one kind alone or two or more kinds in combination, in which case the blending ratio of each resin is not particularly limited.

[0013] Polypropylene refers to a polymer whose base unit is propylene. Ethylene-propylene copolymer refers to a copolymer whose base units are ethylene and propylene. Propylene-1-butene copolymer refers to a copolymer whose base units are propylene and 1-butene. Ethylene-propylene-1-butene copolymer refers to a copolymer whose base units are propylene, 1-butene, and ethylene. Polypropylene, ethylene-propylene copolymer, propylene-1-butene copolymer, and ethylene-propylene-1-butene copolymer may contain a small amount of olefin components other than their respective base units. Such olefin components may be mixed in, for example, during the process leading up to the production of the modified polyolefin resin. The content of the olefin components in polypropylene, ethylene-propylene copolymer, propylene-1-butene copolymer, and ethylene-propylene-1-butene copolymer may be any amount that does not significantly impair the inherent performance of the resin.

[0014] The component composition of the polyolefin resin is not particularly limited, but the propylene component in the total polyolefin resin is preferably 50 mol % or more.

[0015] The above polyolefin resin is modified with an α,β-unsaturated carboxylic acid and / or a derivative thereof to obtain a modified polyolefin resin.

[0016] (α,β-unsaturated carboxylic acid and / or its derivative) The term "α,β-unsaturated carboxylic acid" refers to an α,β-unsaturated compound having a carboxy group. The term "derivative of α,β-unsaturated carboxylic acid" refers to an anhydride, mono- or diester, amide, imide, etc. of the unsaturated compound. Examples of α,β-unsaturated carboxylic acids or derivatives thereof include fumaric acid, maleic acid, itaconic acid, mesaconic acid, citraconic acid, aconitic acid, and anhydrides thereof; monomethyl fumarate, monoethyl fumarate, monopropyl fumarate, monobutyl fumarate, dimethyl fumarate, diethyl fumarate, dipropyl fumarate, dibutyl fumarate, monomethyl maleate, monoethyl maleate, monopropyl maleate, monobutyl maleate, dimethyl maleate, diethyl maleate, dipropyl maleate, dibutyl maleate, maleimide, and N-phenylmaleimide. When obtaining a modified polyolefin resin, the α,β-unsaturated carboxylic acid or its derivative may be used alone or in combination of two or more. In the latter case, the compounding ratio of each compound is not particularly limited.

[0017] The α,β-unsaturated carboxylic acid and / or derivative thereof preferably includes an α,β-unsaturated dicarboxylic acid, and preferably includes one or more selected from the group consisting of itaconic anhydride, maleic anhydride, and maleic acid, more preferably one or more selected from the group consisting of itaconic anhydride, maleic anhydride, and maleic acid, and even more preferably maleic anhydride.

[0018] The graft amount of α,β-unsaturated carboxylic acid and / or its derivative in the modified polyolefin resin of the present invention is preferably 4.0 to 8.0% by weight. When the graft amount of α,β-unsaturated carboxylic acid or its derivative in the modified polyolefin resin is 4.0 to 8.0% by weight, the affinity for each of the filler and the thermoplastic resin is improved, and compatibility is exhibited. The graft amount of the α,β-unsaturated carboxylic acid or its derivative in the modified polyolefin resin can be determined by alkali titration.

[0019] During the production of the modified polyolefin resin, the α,β-unsaturated carboxylic acid or derivative thereof that is not graft polymerized onto the polyolefin resin, i.e., the unreacted material, may be removed during the production of the modified polyolefin resin, for example, by extraction with a poor solvent.

[0020] The polyolefin resin may be further modified with a compound other than an α,β-unsaturated carboxylic acid or a derivative thereof. Examples of the compound other than an α,β-unsaturated carboxylic acid or a derivative thereof include (meth)acrylic acid esters. By further modifying the polyolefin resin with a (meth)acrylic acid ester, compatibility with polar substances to be mixed is improved.

[0021] A (meth)acrylic acid ester is a compound containing at least one (meth)acryloyl group in the molecule. In this specification, "(meth)acryloyl group" means an acryloyl group and / or a methacryloyl group. The (meth)acrylic acid ester is preferably a compound represented by the following general formula (1): CH2=CR1COOR2 (1)

[0022] In general formula (1), R1 represents a hydrogen atom or a methyl group, preferably a methyl group, and R2 represents CnH2n+1, where n represents an integer of 1 to 18, preferably an integer of 1 to 15, and more preferably an integer of 1 to 13.

[0023] Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, glycidyl (meth)acrylate, octyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 1-hydroxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, and (meth)acryloylmorpholine. Among these, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, and tridecyl (meth)acrylate are preferred, and octyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, and tridecyl (meth)acrylate are more preferred. The (meth)acrylic acid ester may be one kind or a combination of two or more kinds, in which case the compounding ratio of each compound is not particularly limited.

[0024] The graft amount of the (meth)acrylic acid ester in the modified polyolefin resin in the present invention is preferably 0.1 to 20.0% by weight, more preferably 0.5 to 10.0% by weight. The graft amount of (meth)acrylic acid ester in the modified polyolefin resin can be determined by 1H-NMR.

[0025] The melting point of the modified polyolefin resin in the present invention is preferably 70 to 140° C., more preferably 73 to 130° C. When the melting point is 70 to 140° C., the flexibility of the interface between the filler and the matrix resin in a resin composition using the modified polyolefin resin is improved, and the impact strength of the composite material can be improved. The melting point of the modified polyolefin resin can be measured by a differential scanning calorimeter (DSC).

[0026] The MFR (melt flow rate) of the modified polyolefin resin in the present invention is preferably 150 to 500 g / 10 min, more preferably 150 to 400 g / 10 min, at a measurement temperature of 165° C. and a measurement load of 1.2 kg. When the MFR is 150 to 500 g / 10 min, the affinity with the filler is improved. The melt flow rate can be measured in accordance with ASTM D1238.

[0027] <Resin composition> The present invention is a resin composition containing a modified polyolefin resin and a filler for resin.

[0028] The base resin used in the resin composition of the present invention is preferably a thermoplastic resin. The thermoplastic resin is preferably molded into granules for ease of handling, but any form may be used. Two or more types of thermoplastic resins may also be used simultaneously.

[0029] Examples of thermoplastic resins include, but are not limited to, polyolefin resins, polyamide resins, and polystyrene resins, and any resin that can be plasticized and molded by heat can be used. Among these, polyethylene such as LDPE (low-density polyethylene) and polypropylene are preferred from the viewpoint of moldability.

[0030] In the present invention, a biodegradable resin may be used as the thermoplastic resin. Examples of biodegradable resins having thermoplastic properties include, but are not limited to, polylactic acid (PLA), polybutylene succinate, polyethylene succinate, polyglycol, polycaprolactone, and polyvinyl alcohol.

[0031] The filler for resin in the present invention can be appropriately selected depending on the desired effect, but in light of recent environmental concerns, biomass-based materials are preferred, and powdered cellulose, which is inexpensive and easy to handle, is more preferred. The filler may be used alone or in combination of two or more types.

[0032] Powdered cellulose can be obtained by pulverizing a cellulose raw material such as pulp that has been subjected to acid hydrolysis with a mineral acid (i.e., an inorganic acid) such as hydrochloric acid, sulfuric acid, or nitric acid, or by mechanically pulverizing a cellulose raw material such as pulp that has not been subjected to acid hydrolysis.

[0033] The average particle size of the powdered cellulose is preferably 5 to 100 μm, more preferably 5 to 50 μm. If the average particle size of the powdered cellulose is larger than 100 μm, it becomes difficult to uniformly mix it with the resin, and problems such as the resin being shredded at the outlet of the device that injects the mixture of the pulverized material and the resin, or difficulty in conveying it to the cooling treatment device, may occur.

[0034] The average particle size is the 50% volume average particle size (D50) measured by laser light scattering (laser diffraction), and can be measured using a laser diffraction / scattering particle size distribution analyzer (manufactured by Malvern Instruments, device name: Mastersizer 2000) or the like.

[0035] The apparent specific gravity of the powdered cellulose is preferably 0.20 g / ml or more, more preferably 0.30 g / ml or more, and the upper limit is preferably 0.60 g / ml or less, more preferably 0.55 g / ml or less, and even more preferably 0.50 g / ml or less. In this specification, the apparent specific gravity is a value calculated by placing 10 g of a sample in a 100 ml measuring cylinder, tapping the bottom of the measuring cylinder until the height of the sample stops decreasing (manually for approximately 10 minutes), and reading the scale on the flat surface.

[0036] The blending ratio of each component in the resin composition is preferably thermoplastic resin: resin filler: modified polyolefin resin = 50-99: 1-50: 0.5-5.0 When each component is in the above blending ratio, a resin composition with excellent mechanical properties can be obtained.

[0037] <Method of manufacturing resin composition> The method for producing the resin composition of the present invention is not particularly limited, but as an example, the resin composition can be obtained by heating, melting, kneading, etc., the above-mentioned components.

[0038] In the method for producing the resin composition of the present invention, equipment commonly used in resin molding can be used. For example, a common extruder, kneading tester, or twin-screw kneading extruder can be used. The Labo Plastomill series manufactured by Toyo Seiki can be used as the kneading tester. Furthermore, the TEX series manufactured by The Japan Steel Works, Ltd. can be used as the twin-screw kneading extruder.

[0039] <Applications of resin composition> The resin composition of the present invention can be used as a molding resin material. When used as a molding resin material, the present invention can be molded for various purposes and can be used as a substitute for plastic products. Molded articles obtained from the molding resin material of the present invention can be widely used, for example, trays, automobile parts, interiors such as automobile dashboards, airplane luggage compartments, structural components for transportation equipment, housings for home appliances, electrical appliance components, cards, various containers such as toner containers, building materials, seedling pots, agricultural sheets, writing implements, wooden products, household appliances, straws, cups, toys, sporting goods, port components, building components, generator components, tools, fishing gear, packaging materials, 3D printer models, pallets, food containers, tableware, cutlery (spoons, forks, etc.), chopsticks, various sheets, etc. [Example]

[0040] The present invention will be described in detail below with reference to examples. The following examples are provided to better illustrate the present invention and are not intended to limit the present invention. Measurement methods for physical properties and the like are as described below unless otherwise specified. Furthermore, "parts" refers to parts by mass. Furthermore, in the following description, unless otherwise specified, the temperature conditions are room temperature (25°C), and unless otherwise specified, the pressure conditions are normal pressure (1 atm).

[0041] [Melting point (℃)] In accordance with JIS K7121-1987, a DSC measuring device (TA Instruments, DISCOVERY DSC2500) was used to measure approximately 5 mg of a sample. The sample was heated to 200°C for 10 minutes and maintained in a molten state, then cooled at a rate of 10°C / min and stabilized at -50°C. The sample was then heated further to 200°C at a rate of 10°C / min until it melted, at which point the peak melting temperature was measured and evaluated as the melting point (°C).

[0042] [Grafting amount (wt%)]: The measurement was carried out by alkali titration in accordance with JIS K-0070 (1992).

[0043] [MFR(g / 10min)]: The measurement was carried out in accordance with ASTM D1238 at a measurement temperature of 165°C and a measurement load of 1.2 kg.

[0044] [Example 1] <Production of modified polyolefin resin> 100 parts of polyolefin resin A (propylene-ethylene copolymer; propylene content 97 mol%, ethylene content 3%, Tm = 125°C), 8.0 parts of maleic anhydride, and 3.0 parts of Trigonox 101 were premixed in a mixer and then heated and kneaded at 190°C in a co-rotating twin-screw extruder to obtain modified polyolefin resin (a). The resulting modified polyolefin resin (a) had a maleic anhydride graft weight of 5.6% by mass, an MFR of 152 g / 10 min, and a melting point of 125°C.

[0045] <Production of Resin Composition> One part of modified polyolefin resin (a) and 79 parts of polypropylene (product name: BC10HRF, manufactured by Japan Polypropylene) were heated and kneaded at 220°C in a co-rotating twin-screw extruder to obtain mixture (1). Eighty parts of mixture (1) and 20 parts of powdered cellulose (W-100GK, average particle size 37 μm, manufactured by Nippon Paper Industries Co., Ltd.) were heated and kneaded at 220°C in a co-rotating twin-screw extruder to obtain resin composition (1).

[0046] [Example 2] A modified polyolefin resin (b) was obtained by the same production method as in Example 1, except that 3 parts of lauryl methacrylate was added. The graft weight of maleic anhydride in the obtained modified polyolefin resin (b) was 5.8 wt%, the MFR was 187 g / 10 min, and the melting point was 125°C.

[0047] A resin composition (2) was obtained in the same manner as in Example 1, except that the modified polyolefin resin (a) was replaced with the modified polyolefin resin (b).

[0048] [Example 3] A modified polyolefin resin (c) was obtained by the same production method as in Example 1, except that 15 parts of 100 parts of the polyolefin resin (A) was changed to polyolefin resin (B) (propylene-1-butene copolymer, Tm = 58°C). The graft weight of maleic anhydride in the obtained modified polyolefin resin (c) was 5.0 wt%, the MFR was 14 g / 10 min, and the melting point was 73 to 125°C.

[0049] A resin composition (3) was obtained in the same manner as in Example 1, except that the modified polyolefin resin (a) was changed to the modified polyolefin resin (c).

[0050] [Example 4] A modified polyolefin resin (d) was obtained by the same production method as in Example 1, except that the polyolefin resin (A) was changed to polyolefin resin (C) (low-crystalline homopolypropylene, melting point 80°C). The maleic anhydride graft weight of the obtained modified polyolefin resin (d) was 4.5 wt%, the MFR was less than 0 g / 10 min, and the melting point was 80°C.

[0051] A resin composition (4) was obtained in the same manner as in Example 1, except that the modified polyolefin resin (a) was changed to the modified polyolefin resin (d).

[0052] [Example 5] A modified polyolefin resin (e) was obtained by the same production method as in Example 1, except that 0.5 parts of lauryl methacrylate was added. The graft weight of maleic anhydride in the obtained modified polyolefin resin (e) was 5.7 wt%, the MFR was 165 g / 10 min, and the melting point was 125°C.

[0053] A resin composition (5) was obtained in the same manner as in Example 1, except that the modified polyolefin resin (a) was changed to the modified polyolefin resin (e).

[0054] [Comparative Example 1] Resin composition (6) was obtained in the same manner as in Example 1, except that the modified polyolefin resin (a) was changed to UM1010 (manufactured by Sanyo Chemical Industries, Ltd., melting point 140°C, graft amount 12.8% by weight).

[0055] Comparative Example 2 A modified polyolefin resin (g) was obtained by the same production method as in Example 1, except that the amount of maleic anhydride was changed from 8.0 parts to 4.0 parts. The graft weight of maleic anhydride in the obtained modified polyolefin resin (g) was 3.9 wt%, the MFR was 200 g / 10 min, and the melting point was 125°C.

[0056] A resin composition (7) was obtained in the same manner as in Example 1, except that the modified polyolefin resin (a) was changed to the modified polyolefin resin (g).

[0057] Comparative Example 3 A modified polyolefin resin (h) was obtained in the same manner as in Example 1, except that the polyolefin resin (A) was changed to polyolefin resin (D) (thermoplastic elastomer, melting point 165°C). The graft weight of maleic anhydride in the obtained modified polyolefin resin (h) was 6.1 wt%, the MFR was 57.6 g / 10 min, and the melting point was 165°C.

[0058] A resin composition (8) was obtained in the same manner as in Example 1, except that the modified polyolefin resin (a) was replaced with the modified polyolefin resin (h).

[0059] Comparative Example 4 A modified polyolefin resin (i) was obtained by the same production method as in Comparative Example 3, except that the amount of maleic anhydride was changed from 8.0 parts to 4.0 parts and 1 part of lauryl methacrylate was added. The graft weight of maleic anhydride in the obtained modified polyolefin resin (i) was 2.6 wt%, the MFR was 206.8 g / 10 min, and the melting point was 165°C.

[0060] Resin composition (9) was obtained in the same manner as above, except that modified polyolefin resin (a) was replaced with modified polyolefin resin (i).

[0061] Comparative Example 5 A modified polyolefin resin (j) was obtained by the same production method as in Comparative Example 2, except that the polyolefin resin (A) was changed to polyolefin resin (E) (propylene-ethylene copolymer; propylene component 91%, ethylene component 9%, melting point 75°C) and 1.5 parts of lauryl methacrylate was added. The graft weight of maleic anhydride in the obtained modified polyolefin resin (j) was 2.6 wt%, the MFR was not measured, and the melting point was 75°C.

[0062] Resin composition (10) was obtained in the same manner as above, except that modified polyolefin resin (a) was replaced with modified polyolefin resin (j).

[0063] Test pieces were prepared from the resin compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 5 using a small electric injection molding machine (SE18-DUZ, manufactured by Sumitomo Heavy Industries, Ltd.). Specifically, the cylinder of the molding machine was heated to 170°C, and the resin composition was filled into the cylinder and held for 90 minutes. The resin composition was then injected into a dedicated mold to prepare a test piece for each resin composition.

[0064] [Impact Strength]: Impact strength was measured in accordance with JIS K 7111-1: 2012. The measured value was divided by the impact strength value measured for polypropylene (product name: BC10HRF, manufactured by Japan Polypropylene) alone to calculate the impact strength retention rate.

[0065] The physical properties of the modified polyolefin resins obtained in Examples 1 to 5 and Comparative Examples 1 to 5 and the resin compositions using the same are shown in Table 1 below.

[0066] [Table 1]

[0067] As shown in Examples 1 to 5 in Table 1, resin compositions containing modified polyolefin resins having a melting point of 70 to 140°C and a graft amount of α,β-unsaturated carboxylic acid and / or its derivative of 4.0 to 8.0 wt % were able to maintain a high level of Charpy impact strength. On the other hand, when the melting point or the graft amount was outside the above range as in Comparative Examples 1 to 5, the retention rate of the Charpy impact strength decreased.

Claims

1. A modified polyolefin resin for use as a filler dispersant for resins, having a melting point of 70 to 140°C and a graft amount of α,β-unsaturated carboxylic acid and / or its derivative of 4.0 to 8.0% by weight.

2. 2. The modified polyolefin resin according to claim 1, wherein the MFR (melt flow rate) measured under conditions of a measurement temperature of 165° C. and a measurement load of 1.2 kg is 150 to 500 g / 10 min.

3. The modified polyolefin resin according to claim 1, which is modified with a (meth)acrylic acid ester.

4. A resin composition comprising the modified polyolefin resin according to claim 1 and a filler for resins.

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