Filler dispersant

Abstract

To provide a filler dispersant which imparts excellent mechanical strength to a thermoplastic resin composition containing a filler, especially, a polyolefin resin composition.SOLUTION: A filler dispersant (K) contains modified polyolefin (X) containing the following polyolefin (A) and an unsaturated (poly) carboxylic acid (anhydride) (C) as constituent raw materials, wherein molecular weight distribution (Mw / Mn) of the modified polyolefin (X) is 4.8 to 6.8. Polyolefin (A): containing α-olefin having 3 to 8 carbon atoms as an essential constituent monomer, and having number average molecular weight of 18,000-50,000.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a filler dispersant.

Background Art

[0002] Polyolefin resins are widely and generally used as films, fibers, and molded products of various other shapes because they are excellent in moldability, rigidity, electrical insulation, etc., and are also inexpensive. In addition, various modifiers have been developed for polyolefin resins, and modifiers containing low molecular weight polyolefins have been proposed for the purpose of improving pigment dispersibility and mechanical strength (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] However, even with the above technology, the mechanical strength was not sufficiently satisfactory. An object of the present invention is to provide a filler dispersant that imparts excellent mechanical strength to a thermoplastic resin composition containing a filler, particularly a polyolefin resin composition.

Means for Solving the Problems

[0005] As a result of intensive studies to solve the above problems, the present inventors have reached the present invention. That is, the present invention is a filler dispersant (K) containing a modified polyolefin (X) composed of the following polyolefin (A) and unsaturated (poly) carboxylic acid (anhydride) (C), and the molecular weight distribution (Mw / Mn) of the modified polyolefin (X) is 4.8 to 6.8. Polyolefin (A): Containing α-olefins with 3 to 8 carbon atoms as constituent monomers, with a number-average molecular weight of 18,000 to 50,000; [Effects of the Invention]

[0006] The filler dispersant (K) of the present invention provides the following effects. (1) To impart excellent mechanical strength (bending strength, impact strength, etc.) to molded articles of thermoplastic resin composition (Z). [Modes for carrying out the invention]

[0007] <Polyolefin (A)> The polyolefin (A) in the present invention contains α-olefins having 3 to 8 carbon atoms as constituent monomers, and has a number-average molecular weight of 18,000 to 50,000.

[0008] In the following text, "α-olefins with 3 to 8 carbon atoms" may be simply referred to as "α-olefins." Examples of the α-olefins mentioned above include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene. Of the α-olefins mentioned above, propylene is preferred from the viewpoint of isotacticity, which will be discussed later.

[0009] The above polyolefin (A) may also contain other monomers besides α-olefins. In that case, based on the total weight of the monomers constituting polyolefin (A), the weight of the other monomers is preferably 20% by weight or less, more preferably 15% by weight or less, and even more preferably 10% by weight or less. Also, based on the total weight of the monomers constituting polyolefin (A), the weight of the other monomers is preferably 0.5% by weight or more, and even more preferably 1.0% by weight or more.

[0010] Other monomers that make up the above polyolefin (A) include, for example, ethylene, 2-butene, isobutene, α-olefins with 9 to 30 carbon atoms (1-decene, 1-dodecene, etc.), and C4 to C30 unsaturated monomers other than α-olefins (for example, vinyl acetate). Of the other monomers mentioned above, ethylene is preferred. Also, of (A), propylene / ethylene copolymer is preferred.

[0011] The number-average molecular weight (Mn) of the above polyolefin (A) is preferably 18,000 to 50,000, more preferably 25,000 to 47,000, and particularly preferably 30,000 to 45,000, from the viewpoint of mechanical strength.

[0012] In this invention, the number-average molecular weight (Mn) and weight-average molecular weight (Mw) can be measured by GPC (gel permeation chromatography). The measurement conditions for Mn by GPC in this invention are as follows: • Equipment: High-temperature gel permeation chromatography ["AllianceGPCV2000", manufactured by Waters Co., Ltd.] • Detection device: Refractive index detector • Solvent: Orthodichlorobenzene • Reference material: Polystyrene • Sample concentration: 3 mg / ml • Column stationary phase: PLgel 10μm, 2 MIXED-B columns in series [Manufactured by Polymer Laboratories Co., Ltd.] Column temperature: 135℃

[0013] The number of double bonds per 1,000 carbon atoms of the above polyolefin (A) [the number of carbon-carbon double bonds at the molecular ends and / or in the molecular chain of polyolefin (A)] is preferably 0.2 to 20, more preferably 0.5 to 18, and even more preferably 1.0 to 15, from the viewpoint of the productivity and mechanical strength of the modified polyolefin (X) described later. Here, the number of double bonds can be determined from the 1 1H-NMR spectrum. That is, the peaks in the spectrum are assigned, and from the integral value derived from the double bond at 4.5 to 6 ppm of the polyolefin (A) and the integral value derived from the polyolefin (A), the relative values of the number of double bonds of the polyolefin (A) and the number of carbon atoms of the polyolefin (A) are determined, and the number of double bonds in the molecular terminals and / or the molecular chain per 1,000 carbon atoms of the polyolefin (A) is calculated. The number of double bonds in the examples described later was in accordance with this method.

[0014] Examples of the method for producing the polyolefin (A) in the present invention include, for example, the following. (1) A method of thermally reducing a high molecular weight (preferably Mn is 60,000 to 800,000, more preferably Mn is 80,000 to 250,000) polyolefin (A0). (2) A method of polymerizing an α-olefin in the presence of a polymerization catalyst.

[0015] Among the above (1) to (2), from the viewpoint of productivity, (1) is preferable.

[0016] The thermal reduction method includes (1) a method of heating the high molecular weight polyolefin (A0) at, for example, 280 to 450 ° C (preferably 290 to 330 ° C) for 0.5 to 100 hours in the absence of an organic peroxide, and (2) a method of heating in the presence of an organic peroxide [for example, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane] at, for example, 180 to 300 ° C for 0.5 to 100 hours, and the like. Among these, from the industrial viewpoint and the viewpoint of the productivity of the modified polyolefin (X), the method of (1) which is more likely to obtain a higher number of double bonds in the molecular terminals and / or the molecular chain is preferable.

[0017] In the above polyolefin (A), the higher the thermal reduction temperature or the longer the thermal reduction time in the thermal reduction step, the more the number of double bonds per 1,000 carbon atoms tends to increase. Furthermore, the smaller the Mn of the high molecular weight polyolefin (A0), the higher the thermal decomposition temperature, or the longer the thermal decomposition time, the more likely the Mn of the polyolefin (A) is to be small. In addition, the polyolefin (A) may be used alone or in combination of two or more.

[0018] <Unsaturated (poly) carboxylic acid (anhydride) (C)> The unsaturated (poly) carboxylic acid (anhydride) (C) in the present invention is an unsaturated monocarboxylic acid, an unsaturated polycarboxylic acid and / or an unsaturated polycarboxylic acid anhydride. The above unsaturated (poly) carboxylic acid (anhydride) (C) is preferably a monocarboxylic acid having 1 polymerizable unsaturated group and 3 to 24 carbon atoms [sometimes abbreviated as C], a polycarboxylic acid having 1 polymerizable unsaturated group and 4 to 24 carbon atoms, and / or a polycarboxylic acid anhydride having 1 polymerizable unsaturated group and 4 to 24 carbon atoms.

[0019] Among the above unsaturated (poly) carboxylic acid (anhydride) (C), examples of the unsaturated monocarboxylic acid include aliphatic monocarboxylic acids (C3 to 24, such as acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, isocrotonic acid), alicyclic-containing monocarboxylic acids (C6 to 24, such as cyclohexenecarboxylic acid); examples of the unsaturated poly(2 to 3 or more) carboxylic acid or its acid anhydride include unsaturated dicarboxylic acids or their acid anhydrides [aliphatic dicarboxylic acids or their acid anhydrides (C4 to 24, such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, and their acid anhydrides), alicyclic-containing dicarboxylic acids or their acid anhydrides (C8 to 24, such as cyclohexenedicarboxylic acid, cycloheptenedicarboxylic acid, bicycloheptenedicarboxylic acid, methyltetrahydrophthalic acid, and their acid anhydrides), etc.]. The unsaturated carboxylic acid (anhydride) (C) may be used alone or in combination of two or more.

[0020] Among the above (poly) unsaturated carboxylic acid (anhydride) (C), from the viewpoints of reactivity with the polyolefin (A) and mechanical strength, an unsaturated dicarboxylic acid anhydride is preferred, and maleic anhydride is more preferred.

[0021] <Modified polyolefin (X)> The modified polyolefin (X) in the present invention is composed of polyolefin (A) and unsaturated (poly)carboxylic acid (anhydride) (C) as constituent raw materials. The modified polyolefin (X) is, for example, a reaction product of polyolefin (A) and unsaturated carboxylic acid (anhydride) (C). In the above reaction, a radical initiator (f) (such as dicumyl peroxide) may be used.

[0022] The acid value (mgKOH / g) of the modified polyolefin (X) is preferably 3.0 to 30 mgKOH / g (only numerical values ​​are shown below), more preferably 4.0 to 25, and particularly preferably 5.0 to 10. The acid value here is measured in accordance with JIS K0070. Furthermore, the above acid value can be appropriately adjusted by the amount of double bonds in the polyolefin (A), the weight of the polyolefin (A), and the type and weight of the unsaturated carboxylic acid (anhydride) (C).

[0023] The Mn (number-average molecular weight) of the modified polyolefin (X) is preferably 18,000 to 50,000, more preferably 25,000 to 47,000, and particularly preferably 30,000 to 45,000, from the viewpoint of balancing mechanical strength.

[0024] The molecular weight distribution (Mw / Mn) of the modified polyolefin (X) is 4.8 to 6.8, and preferably 5.0 to 6.5 from the viewpoint of mechanical strength. The molecular weight distribution (Mw / Mn) is the value obtained by dividing the weight-average molecular weight (Mw) by the number-average molecular weight (Mn). Furthermore, the following methods can be used to adjust the molecular weight distribution (Mw / Mn). (1) When a high molecular weight polyolefin (A0) with a large molecular weight distribution (Mw / Mn) is used, the molecular weight distribution (Mw / Mn) of the modified polyolefin (X) tends to be large. (2) The lower the temperature at which high molecular weight polyolefin (A0) is thermally reduced, the greater the molecular weight distribution (Mw / Mn) of the modified polyolefin (X).

[0025] <Filler dispersant (K)> The filler dispersant (K) of the present invention contains the modified polyolefin (X). The filler dispersant (K) may optionally contain (N2) to (N10) from the additives (N) described below. In that case, the weight of the modified polyolefin (X) based on the weight of the filler dispersant (K) is preferably 90 to 99.9% by weight. The filler dispersant (K) of the present invention imparts excellent mechanical strength (flexural strength, impact strength) to molded articles of the thermoplastic resin composition (Z) described later.

[0026] <Thermoplastic resin composition (Z)> The thermoplastic resin composition (Z) of the present invention contains the above-mentioned filler dispersant (K), a thermoplastic resin (Y), and a filler (N1).

[0027] Examples of thermoplastic resins (Y) other than those mentioned above (X) include polyolefin resins [polypropylene, low-density polyethylene, high-density polyethylene], polystyrene resins, polyester resins, and nylon resins. Of the above thermoplastic resins (Y), polyolefin resins are preferred.

[0028] The manganese content (Mn) of the thermoplastic resin (Y) is preferably 60,000 to 500,000, more preferably 70,000 to 400,000, and even more preferably 80,000 to 300,000, from the viewpoint of the mechanical strength of the molded product and compatibility with the filler dispersant (K).

[0029] Examples of fillers (N1) include organic fillers (e.g., wood flour, cellulose, paper) and inorganic fillers (e.g., calcium carbonate, talc, glass fiber, carbon fiber). Of these fillers (N1), inorganic fillers are preferred from the viewpoint of mechanical strength, and calcium carbonate is even more preferred.

[0030] The weight ratio [(K) / (Y)] of the filler dispersant (K) to the thermoplastic resin (Y) is preferably 3 / 97 to 25 / 75, and more preferably 6 / 94 to 20 / 80, from the viewpoint of mechanical strength. Furthermore, the weight ratio [(N1) / {(K)+(Y)}] of the filler (N1) to the total of the filler dispersant (K) and thermoplastic resin (Y) is preferably 10 / 90 to 75 / 25, and more preferably 25 / 75 to 60 / 40, from the viewpoint of mechanical strength.

[0031] The thermoplastic resin composition (Z) of the present invention may further contain one or more additives (N) selected from the group consisting of colorants (N2), matting agents (N3), antistatic agents (N4), dispersants (N5), flame retardants (N6), foaming agents (N7), antioxidants (N8), ultraviolet absorbers (N9), and plasticizers (N10), as necessary, to the extent that they do not impede the effects of the present invention.

[0032] The amount of each additive (N) used, based on the total weight of the thermoplastic resin composition (Z), is as follows: (N2) is, for example, 10% by weight or less, preferably 1 to 5% by weight; (N3) is, for example, 20% by weight or less, preferably 1 to 10% by weight; (N4) is, for example, 10% by weight or less, preferably 1 to 5% by weight; (N5) is, for example, 20% by weight or less, preferably 0 to 15% by weight, more preferably 0 to 10% by weight; (N6) is, for example, 15% by weight or less, preferably 3 to 10% by weight; (N7) is, for example, 1 to 20% by weight or less, preferably 5 to 15% by weight; (N8) is, for example, 3% by weight or less, preferably 0.01 to 1% by weight; (N9) is, for example, 3% by weight or less, preferably 0.01 to 1% by weight; (N10) is, for example, 20% by weight or less, preferably 5 to 15% by weight.

[0033] Furthermore, if the same additives are used and overlap between (N2) and (N10), the amount used should not be adjusted according to the intended purpose, taking into consideration that the effects of other additives may also be obtained simultaneously, rather than using the amount that provides the corresponding additive effect for each additive regardless of the effects of other additives.

[0034] The method for producing the thermoplastic resin composition (Z) of the present invention is as follows: (1) A method of mixing the entire amounts of thermoplastic resin (Y), filler dispersant (K), and filler (N1), and optionally (N), in a single mixture to obtain a resin composition (single-mix method); (2) A method (masterbatch method) is used in which a masterbatch resin composition is prepared by first mixing a portion of the thermoplastic resin (Y), the filler dispersant (K), the entire amount of the filler (N1), and, if necessary, a portion or all of the additive (N), and then the remaining thermoplastic resin (Y) and, if necessary, the remaining additive (N) are added and mixed to form a resin composition. From the viewpoint of the mixing efficiency of the filler dispersant (K), method (2) is preferred.

[0035] <Molded products> The molded article of the present invention is a molded article of the above thermoplastic resin composition (Z). In other words, the molded article of the present invention is a molded article of the above thermoplastic resin composition (Z). Molding methods include injection molding, compression molding, calendering, slush molding, rotational molding, extrusion molding, blow molding, and film molding (casting method, tenter method, inflation method, etc.). Depending on the purpose, molding can be done using any method that incorporates single-layer molding, multi-layer molding, or foam molding. Molded products can take the form of plates, sheets, films, fibers (including nonwoven fabrics, etc.). [Examples]

[0036] The present invention will be further described by the following examples, but the present invention is not limited thereto. In the examples, parts represent parts by weight. In the examples, the number average molecular weight (Mn), weight average molecular weight (Mn), the number of double bonds in the polyolefin, and the acid value were measured by the method described above. In the following, Examples 7 and 48 are Reference Examples 1 and 2, respectively.

[0037] <Manufacturing Example 1> 100 parts of high molecular weight polyolefin (A0-1) [product name "Sun Allomer PLA00A", manufactured by Sun Allomer, the same applies hereinafter] were charged into a reaction vessel, and while supplying nitrogen gas to the liquid phase, it was heated and melted using a mantle heater, and thermal reduction was carried out at 310°C for 1200 minutes while stirring to obtain polyolefin (A-1). Furthermore, the manganese content of polyolefin (A-1) was 40,000, and the number of double bonds at the molecular ends and / or in the molecular chain per 1,000 carbon atoms was 2.5.

[0038] <Manufacturing Examples 2-13> Except for changing the high molecular weight polyolefin (A0), temperature, and time according to Table 1, thermal desorption was performed in the same manner as in Production Example 1 to obtain each polyolefin (A). The results are shown in Table 1.

[0039] [Table 1]

[0040] <Example 1> In a reaction vessel, 100 parts of polyolefin (A-1), 3 parts of maleic anhydride (C-1), and 1 part of dicumyl peroxide (f-1) were charged and heated to 200°C under nitrogen aeration, with stirring continued for 10 hours. Thereafter, unreacted maleic anhydride was removed by distillation under reduced pressure (1.5 kPa, the same applies hereafter) to obtain a filler dispersant (K-1) containing modified polyolefin (X-1). Furthermore, the modified polyolefin (X-1) had an acid value of 7.8, a manganese content of 40,000, and a manganese content of 5.8.

[0041] <Examples 2-15, Comparative Example 1> The reaction was carried out in the same manner as in Example 1, except that the polyolefin (A), unsaturated (poly)carboxylic acid (anhydride) (C), and radical initiator (f) were changed according to Table 2, to obtain each filler dispersant (K). The results are shown in Table 2.

[0042] [Table 2]

[0043] <Examples 21-56, Comparative Example 21> According to the formulations (parts) in Tables 3 and 4, each filler dispersant (K), thermoplastic resin (Y), and filler (N1) were melt-kneaded in a twin-screw extruder [product name "KZW45TW", manufactured by Technovel Co., Ltd.] at 230°C and 100 rpm to obtain each thermoplastic resin composition (Z). Each thermoplastic resin composition (Z) was injection molded using an injection molding machine [product name "PS40E5ASE", manufactured by Nissei Plastics Co., Ltd.] at a nozzle temperature of 230°C and a mold temperature of 50°C, and evaluated according to the evaluation method described below. The results are shown in Tables 3 and 4.

[0044] (1) Bending strength The bending strength of the molded article of composition (Z) in the example was measured in accordance with ASTM D790, and the improvement rate (%) was calculated using the following formula. Improvement in bending strength (%) = (Bending strength of the example) × 100 / (Bending strength of the comparison) Comparative flexural strength: In each example's formulation (parts), the comparative dispersant (ratio K-1) was used instead of the dispersant in the example, and the flexural strength was measured in the same manner as in each example. Next, the improvement rate (%) of bending strength calculated above was evaluated according to the following <evaluation criteria>. <Evaluation Criteria> ◎:More than 150% ○: More than 100%, less than 150% △: More than 75%, less than 100% ×: Less than 75%

[0045] (2) Izod impact strength The Izod impact strength of the molded product of composition (Z) in the example was measured in accordance with JIS K7110, and the improvement rate (%) of the Izod impact strength was calculated using the following formula. Improvement in Izod impact strength (%) = (Izod impact strength of the example) × 100 / (Izod impact strength of comparison) Comparative Izod impact strength: In each example's formulation (parts), the comparative dispersant (ratio K-1) was used instead of the dispersant in the example, and the Izod impact strength was measured in the same manner as in each example. Next, the improvement rate (%) of Izod impact strength calculated above was evaluated according to the following <evaluation criteria>. <Evaluation Criteria> ◎:More than 150% ○: More than 100%, less than 150% △: More than 75%, less than 100% ×: Less than 75%

[0046] [Table 3]

[0047] [Table 4]

[0048] The results in Tables 1-4 show that the filler dispersant (K) of the present invention provides superior mechanical strength to molded articles of thermoplastic resin composition (Z) compared to the comparative one. [Industrial applicability]

[0049] The filler dispersant (K) of the present invention exhibits excellent dispersion effects for various fillers, thereby imparting superior mechanical strength (flexural strength, impact strength, etc.) to molded articles of thermoplastic resin compositions (Z). For this reason, it is extremely useful for various applications of molded articles made from thermoplastic resins.

Claims

1. A filler dispersant (K) comprising a modified polyolefin (X) composed of the following polyolefin (A) and unsaturated (poly)carboxylic acid (anhydride) (C), wherein the molecular weight distribution (Mw / Mn) of the modified polyolefin (X) is 4.8 to 6.

8. Polyolefin (A): A propylene / ethylene copolymer in which, based on the total weight of the monomers constituting polyolefin (A), the weight of ethylene is 0.5% by weight or more and less than 3.0% by weight, and the number average molecular weight is 18,000 to 50,000;

2. The filler dispersant according to claim 1, wherein the polyolefin (A) has 0.2 to 20 double bonds per 1,000 carbon atoms.

3. The filler dispersant according to claim 1, wherein the acid value (mgKOH / g) of the modified polyolefin (X) is 3.0 to 50.

4. A thermoplastic resin composition (Z) comprising a filler dispersant (K) according to claim 1, a thermoplastic resin (Y), and a filler (N1).

5. The thermoplastic resin composition according to claim 4, wherein the weight ratio of the filler dispersant (K) to the thermoplastic resin (Y) [(K) / (Y)] is 5 / 95 to 25 / 75.

6. The thermoplastic resin composition according to claim 4, wherein the weight ratio of the filler (N1) to the total of the filler dispersant (K) and thermoplastic resin (Y) [(N1) / {(K)+(Y)}] is 10 / 90 to 75 / 25.

7. A molded article obtained by molding a thermoplastic resin composition (Z) according to any one of claims 4 to 6.

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