Polypropylene resin composition, molded article, and molded article for automobile interior parts

Abstract

To provide a polypropylene-based resin composition which suppresses fogging and generation of aldehydes without impairing antistatic properties.SOLUTION: The polypropylene-based resin composition is obtained by blending 100 pts.mass of a polypropylene-based resin (A) with 0-0.5 pt.mass of a monoglycerol fatty acid ester (B), 0.01-1.0 pt.mass of a diglycerol fatty acid ester (C), and 0.001-0.8 pt.mass of a fatty acid diethanolamide (D) and does not substantially contain an alkyldiethanolamine and / or a fatty acid ester of an alkyldiethanolamine.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polypropylene resin composition, a molded article, and a molded article for an automobile interior part. [Background technology]

[0002] Automotive interior materials are made from molded resin compositions containing polypropylene resin with inorganic fillers and rubber added, but it is desirable that dust not adhere to the interior materials after molding and when delivered to the user. Since dust adhesion is mainly caused by static electricity, it is common to add antistatic agents to reduce the electrical resistance of the interior material surface and thereby release static electricity in order to make it less likely to adhere.

[0003] However, antistatic agents are easily adsorbed by inorganic fillers such as talc, making it difficult to achieve antistatic performance. If the amount of antistatic agent added is increased in order to achieve antistatic performance, the antistatic agent will vaporize and adhere to the windshield and other surfaces when the temperature inside the automobile rises, such as in the summer, causing a problem known as fogging, in which the transparency of the glass is impaired. For these reasons, automobile interior materials are required to be free from dust adhesion to the interior materials themselves and to ensure that the transparency of the automobile glass is not impaired by the adhesion of the antistatic agent.

[0004] Patent Document 1 discloses a resin composition for automotive interior materials that has excellent antistatic and anti-fogging properties. The composition comprises 30 to 82 parts by weight of a propylene-ethylene block copolymer (component A) containing 5 to 20% by weight of a propylene-ethylene random copolymer having an ethylene content of 25 to 75% by weight, 10 to 40 parts by weight of talc (component B), and 8 to 30 parts by weight of an olefin-based elastomer (component C), for a total of 100 parts by weight, with the total of components B and C being 20 to 60 parts by weight, and 0.3 to 0.45% by weight of an antistatic agent (component D) consisting of a mixture of monoglycerin fatty acid ester, diglycerin fatty acid ester, and alkyldiethanolamine.

[0005] Patent Document 2 discloses a polypropylene resin composition characterized by containing (A) 50 to 90 parts by weight of a crystalline polypropylene resin, (B) 10 to 50 parts by weight of an inorganic filler, (C) 0 to 40 parts by weight of rubber (wherein the total amount of components (A), (B), and (C) is 100 parts by weight), and (D) 0.01 to 3 parts by weight of palmitic acid diethanolamide.

[0006] Patent Document 3 discloses a polypropylene resin composition containing 100 parts by weight of a propylene polymerization material, 0.1 to 0.4 parts by weight of at least one ester compound selected from the group consisting of monoglycerin fatty acid esters and diglycerin fatty acid esters, 0.2 to 0.8 parts by weight of an antistatic agent containing 0.1 to 0.4 parts by weight of stearyldiethanolamine monostearate, 0.01 to 0.4 parts by weight of N,N'-di(hydroxyethyl)alkylamide, and 0.01 to 0.3 parts by weight of a hindered amine light stabilizer. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 11-323070 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-212353 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-201615 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the polypropylene resin compositions described in the above patent documents do not have sufficient anti-fogging properties, and the amount of volatile organic compounds (VOCs), particularly aldehydes such as acetaldehyde and formaldehyde, emitted is not satisfactory. The present invention aims to solve the above-mentioned problems in the prior art, and aims to provide a polypropylene resin composition that suppresses fogging and the generation of aldehydes without impairing antistatic properties. [Means for solving the problem]

[0009] As a result of extensive research to solve the above problems, the present inventors have discovered that alkyldiethanolamines and fatty acid esters of alkyldiethanolamines, which have conventionally been widely used as antistatic agents for polypropylene-based resins, are associated with fogging and the generation of aldehydes, and have thus completed the present invention.

[0010] That is, the present invention is as follows. [1] For 100 parts by mass of polypropylene resin (A), 0 to 0.5 parts by mass of monoglycerin fatty acid ester (B), 0.01 to 1.0 parts by mass of diglycerin fatty acid ester (C), and Fatty acid diethanolamide (D) 0.001 to 0.2 parts by mass A polypropylene resin composition comprising: A polypropylene resin composition characterized by being substantially free of alkyldiethanolamine and / or fatty acid ester of alkyldiethanolamine. [2] The polypropylene resin composition according to [1], which is substantially free of methanol derived from the component (D). [3] For 100 parts by mass of polypropylene resin (A), The polypropylene resin composition according to [1] or [2], wherein the components (B), (C) and (D) are blended in a total amount of 0.1 to 1.5 parts by mass. [4] The polypropylene resin composition according to any one of [1] to [3], wherein the mass ratio of the total of the components (B) and (C) to the component (D) is [(B) + (C)] / (D) = 1 / 99 to 99 / 1. [5] A molded article obtained by molding the polypropylene resin composition according to any one of [1] to [3]. [6] An injection-molded article obtained by molding the polypropylene resin composition according to any one of [1] to [3]. [7] A molded article for automobile interior parts, obtained by molding the polypropylene resin composition according to any one of [1] to [3]. [Effects of the Invention]

[0011] The polypropylene resin composition of the present invention and the molded article obtained by molding the same can significantly suppress fogging and the generation of aldehydes while maintaining the antistatic properties necessary to prevent adhesion of dust, etc. Furthermore, since the composition does not become cloudy due to bleed-out, it can be preferably used as an automobile interior part. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below. The polypropylene resin (A) constituting the polypropylene resin composition of the present invention can be appropriately selected from conventionally known polypropylene resins. Examples of such polypropylene resin (A) include propylene homopolymers, propylene-α-olefin random copolymers and propylene block copolymers, which are copolymers of propylene and an α-olefin other than propylene. The polypropylene resin (A) may also be modified with a polar group-containing monomer such as maleic anhydride. The polypropylene resin (A) may be used singly or in combination of two or more.

[0013] Preferred polypropylene resins (A) include propylene homopolymers, propylene-α-olefin random copolymers containing 30% by weight or less, preferably 5% by weight or less, of other α-olefin units, and propylene block copolymers having an n-decane extractable content of 10% by weight or less, particularly 8% by weight or less. The term "α-olefin unit" refers to a structural unit derived from an α-olefin and constituting a polymer. In the present invention, α-olefin includes ethylene.

[0014] The other α-olefin forming the propylene-α-olefin random copolymer or propylene block copolymer is preferably an α-olefin other than propylene having 2 to 20 carbon atoms, specifically ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-hexadecene, 4-methyl-1-pentene, etc. These α-olefins may be used alone or in combination of two or more.

[0015] Propylene block copolymers are usually obtained in multiple series-connected polymerization reactors, for example, by producing a propylene homopolymer in a first polymerization reactor and producing a propylene-α-olefin random copolymer rubber (typically a propylene-ethylene random copolymer rubber) in the presence of the propylene homopolymer in a second polymerization reactor, and the propylene homopolymer and propylene-α-olefin random copolymer rubber are uniformly mixed. When a propylene block copolymer is used as polypropylene resin (A), the incorporation of a rubber component can be omitted if there is a sufficient amount of copolymer rubber in the propylene block copolymer.

[0016] The polypropylene resin (A) used in the present invention can be produced by a known method using a known solid titanium catalyst or metallocene catalyst.

[0017] The polypropylene resin (A) has a melt flow rate MFR (230°C, under a load of 2.16 kg) measured in accordance with ASTM D1238 of usually 0.1 to 300 g / 10 min, preferably 1 to 100 g / 10 min, and more preferably 50 g / 10 min.

[0018] The monoglycerin fatty acid ester (B) is an ester compound obtained by a known method such as an esterification reaction between monoglycerin and a fatty acid or a transesterification reaction between monoglycerin and a fatty acid lower alkyl alcohol ester, and is preferably a monoglycerin fatty acid ester compound obtained from monoglycerin and a fatty acid having 8 to 22 carbon atoms, but di-fatty acid esters and tri-fatty acid esters may also be present. These may be distilled or may be used as is.

[0019] Examples of fatty acids having 8 to 22 carbon atoms include saturated fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, 12-hydroxystearic acid, arachidic acid, and behenic acid, and unsaturated fatty acids such as decenoic acid, undecenoic acid, dodecenoic acid, tetradecenoic acid, oleic acid, erucic acid, linoleic acid, linolenic acid, and ricinoleic acid. Of these, from the viewpoints of antistatic properties and bleeding properties, lauric acid, myristic acid, palmitic acid, and stearic acid are preferred, and palmitic acid and stearic acid are particularly preferred.

[0020] In the present invention, the monoglycerin fatty acid ester (B) is blended in an amount of 0 to 0.5 parts by mass relative to 100 parts by mass of the polypropylene resin (A), but from the viewpoint of antistatic properties and anti-fogging properties, it is blended in an amount of preferably 0.01 to 0.5 parts by mass, more preferably 0.05 to 0.4 parts by mass, and even more preferably 0.1 to 0.3 parts by mass.

[0021] The diglycerin fatty acid ester (C) is an ester compound obtained by a known method such as an esterification reaction between diglycerin and a fatty acid or a transesterification reaction between diglycerin and a fatty acid lower alkyl alcohol ester, and is preferably a mono-fatty acid ester compound of diglycerin obtained from diglycerin and a fatty acid having 8 to 22 carbon atoms, but di-fatty acid esters and tri-fatty acid esters may also be present. These may be distilled or may be used as is.

[0022] The raw material diglycerin preferably contains 90% by mass or more of diglycerin obtained by condensing 2 moles of glycerin, but polyglycerin obtained by condensing 3 or 4 moles of glycerin may also be present. The fatty acid having 8 to 22 carbon atoms can be the same as that used in the monoglycerin fatty acid ester (B).

[0023] In the present invention, the diglycerin fatty acid ester (C) is blended in an amount of 0.01 to 1.0 part by mass relative to 100 parts by mass of the polypropylene resin (A), but from the viewpoint of antistatic properties and anti-fogging properties, it is blended in an amount of preferably 0.1 to 0.8 part by mass, more preferably 0.2 to 0.6 part by mass.

[0024] The fatty acid diethanolamide (D) used in the present invention is a compound represented by the following general formula (1).

[0025] [ka] (In the formula, R 1 represents an alkyl or alkenyl group having 5 to 19 carbon atoms.

[0026] Specific examples of the fatty acid diethanolamide (D) represented by the general formula (1) include coconut fatty acid diethanolamide, lauric acid diethanolamide, tridecylic acid diethanolamide, pentadecylic acid diethanolamide, palmitic acid diethanolamide, heptadecylic acid diethanolamide, oleic acid diethanolamide, stearic acid diethanolamide, nonadecanoic acid diethanolamide, and arachidic acid diethanolamide. Among these, lauric acid diethanolamide is preferred from the viewpoint of anti-fogging properties. The fatty acid diethanolamide (D) can be used alone or in combination of two or more.

[0027] The fatty acid diethanolamide (D) as described above can be prepared by conventional methods, for example, by reacting a fatty acid or a fatty acid lower alkyl alcohol ester with diethanolamine. Therefore, in addition to the compound represented by general formula (1), fatty acid diethanolamide and fatty acid monoester, fatty acid diester, diethanolamine and fatty acid monoester, diethanolamine and fatty acid diester, unreacted diethanolamine, unreacted fatty acid, and unreacted fatty acid lower alkyl alcohol ester may be present. However, since remaining unreacted fatty acid can cause odor and coloration, it is preferable to use a fatty acid lower alkyl alcohol ester, especially a fatty acid methyl ester. The reaction ratio of fatty acid or fatty acid lower alkyl alcohol ester to diethanolamine is preferably 0.9 to 1.1 moles, but is not limited to this. To promote the reaction, a commonly known condensation reaction catalyst can be used, such as a titanium catalyst, a metal alcoholate catalyst, a tin catalyst, or a Bronsted acid catalyst.

[0028] In the present invention, the fatty acid diethanolamide (D) is blended in an amount of 0.001 to 0.8 parts by mass, preferably 0.005 to 0.5 parts by mass, and more preferably 0.01 to 0.2 parts by mass, per 100 parts by mass of the polypropylene resin (A).

[0029] The fatty acid diethanolamide (D) produced using a fatty acid methyl ester contains methanol generated by a transesterification reaction. If residual methanol remains in the polypropylene resin composition, it tends to generate formaldehyde when heated during molding, so it is preferable to remove it by topping or the like. The content of residual methanol can be measured by headspace gas chromatography or by Method 3 of the Quasi-drug Raw Materials Standards (QDS). It is preferable that the polypropylene resin composition contains substantially no residual methanol. Here, "substantially no residual methanol" means that the amount of residual methanol in the polypropylene resin composition is 10 ppm or less, preferably 5 ppm or less, and more preferably 1 ppm or less.

[0030] The polypropylene resin composition of the present invention is characterized by being substantially free of alkyldiethanolamine and / or alkyldiethanolamine fatty acid ester. By being substantially free of these antistatic agents that have been widely used in the past, fogging and the generation of aldehydes can be significantly suppressed. Here, "substantially free" means that the content of these antistatic agents is 10 ppm or less, preferably 1 ppm or less, and more preferably 0 ppm, relative to the polypropylene resin composition.

[0031] The total amount of the components (B), (C), and (D) contained in the polypropylene resin composition is preferably in the range of 0.1 to 1.5 parts by mass per 100 parts by mass of the polypropylene resin, from the viewpoint of imparting an excellent antistatic effect to the polypropylene resin composition. The content of the surfactant composition is preferably in the range of 0.2 to 1.0 part by mass. By keeping the content within this range, particularly excellent antistatic properties can be imparted.

[0032] The mass ratio of the total of the (B) and (C) components to the (D) component is preferably [(B) + (C)] / (D) = 1 / 99 to 99 / 1, more preferably 51 / 49 to 95 / 5, and even more preferably 70 / 30 to 95 / 5, from the viewpoint of imparting antistatic properties. Furthermore, from the viewpoint of anti-fogging properties, the mass ratio is preferably 49 / 51 to 5 / 95, and even more preferably 5 / 95 to 30 / 70.

[0033] The polypropylene resin composition of the present invention can contain an inorganic filler to reinforce and increase the volume of the polypropylene resin composition. The inorganic filler is not particularly limited, but examples include talc, calcium carbonate, barium sulfate, aluminum hydroxide, gypsum, dawsonite, simgon, radiolite, celite, novacite, asbestos, alumina, attapulgite, kaolin gray, volcanic ash, silica, wollastonite, diatomaceous earth, magnesium oxide, magnesium carbonate, feldspar powder, biotite, and magnesium silicate. Among these, talc is preferred. These inorganic fillers may be used alone or in combination.

[0034] The polypropylene resin composition of the present invention can be blended with various rubber components to impart flexibility, impact resistance, and other properties to the composition. Examples of rubber components include, but are not limited to, ethylene-α-olefin copolymer rubber, ethylene-α-olefin-non-conjugated diene copolymer rubber, natural rubber, isoprene rubber, polybutadiene rubber, isobutylene-isoprene copolymer rubber, acrylonitrile-butadiene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene copolymer rubber, silicone rubber, acrylic rubber, chloroprene rubber, and hydrogenated versions of the above rubbers. Among these, ethylene-α-olefin copolymer rubber and ethylene-α-olefin-non-conjugated diene copolymer rubber (hereinafter, the term "ethylene-based copolymer rubber" refers to both) are preferred. The above rubbers can be used alone or in combination.

[0035] The ethylene copolymer rubber preferably used as the rubber component will be described below. α-olefins copolymerized with ethylene, preferably α-olefins having 3 to 10 carbon atoms, include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 1-decene. Two or more of these α-olefins can be used in combination. The ethylene component content of the ethylene copolymer rubber is 60 to 90 mol %, preferably 70 to 85 mol %, from the viewpoint of impact resistance.

[0036] Examples of non-conjugated dienes include dicyclopentadiene, 1,4-hexadiene, 1,9-decadiene, cyclooctadiene, norbornadiene, methylenenorbornene, ethylidenenorbornene, and 7-methyl-1,6-octadiene.

[0037] The iodine value of the ethylene-α-olefin-non-conjugated diene copolymer is preferably 5 to 50, more preferably 10 to 45. The Mooney viscosity (ML 1+4 , 100°C) is 10 to 100, preferably 20 to 60, from the viewpoint of dispersibility in the polypropylene resin and impact resistance.

[0038] The ethylene copolymer rubber can be obtained by copolymerization in the presence of a vanadium, titanium or metallocene catalyst by a known polymerization method.

[0039] Furthermore, in each process up to the production of molded articles for automobile interior parts from polypropylene-based resins, high molecular weight polymers such as poly(4-methyl-1-pentene), polystyrene, polybutadiene, or styrene-grafted polymers of polyisoprene, copolymer elastomers obtained by hydrogenating these polymers, polyesters, polyamides, and polycarbonates may be added depending on the intended use, within the range that does not significantly impair the effects of the present invention. The blending amount of these high molecular weight polymers is usually up to 5% by mass, preferably up to 3% by mass.

[0040] In addition to the polypropylene resin, other polymers or elastomers, antistatic agents, and inorganic fillers, additives widely used in the fields of synthetic resins and synthetic rubbers, such as stabilizers against heat, oxygen, light, etc., weathering agents, crystal nucleating agents, lubricants, flame retardants, and plasticizers, may be added to the polypropylene resin composition of the present invention depending on the intended use, provided that the effects of the present invention are not significantly impaired. In the present invention, a pigment may be further added to the polypropylene resin to which these stabilizers or various additives have been added.

[0041] Examples of stabilizers against heat and oxygen include phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Examples of weathering agents that prevent deterioration due to light include amine-based, triazole-based, benzophenone-based, benzoate-based, nickel-based, and salicylic acid-based compounds. Examples of crystal nucleating agents include sorbitol-based, phosphorus-based, rosin-based, organic phosphate ester metal salts, and carboxylic acid metal salts. Examples of lubricants include fatty acid amides, higher alcohols, and polyethylene wax. Examples of flame retardants include phosphate-based, melamine-based, phosphorus-based, halogen-based, and non-halogen-based compounds. Examples of plasticizers include phthalate-based, fatty acid-based, adipate-based, trimellitate-based, epoxy-based, and polyester-based compounds.

[0042] Examples of pigments include inorganic pigments and organic pigments. Inorganic pigments have a color-producing portion made of inorganic matter, and include those composed of simple elements as components, as well as oxides, sulfides, and sulfates of Zn, Pb, Ti, Sb, Cd, Fe, As, Mg, Al, Co, Cr, and the like. Organic pigments have a color-producing portion made of organic compounds, and include azo pigments, polyazo pigments, azine pigments, copper phthalocyanine pigments, dioxane pigments, and quinacridone pigments. To improve the dispersibility of pigments in polypropylene, dispersing aids (such as fatty acid metal salts, naphthenic acid metal salts, surfactants, silicone oil, and lecithin) may be used.

[0043] Molded articles from the polypropylene resin composition of the present invention can be produced by blending the (B) to (D) components of the present invention with the main polypropylene resin by conventional methods. Other polymers, inorganic fillers, pigments, and other additives may also be blended. For example, the (B) to (D) components of the present invention, and optionally inorganic fillers, pigments, and other additives, are blended with a powdered or pelletized polypropylene resin and other polymers, mixed using a Henschel mixer, tumbler mixer, or the like, and then melt-kneaded and pelletized using a single- or twin-screw kneading extruder. The pellets thus obtained are then processed into molded articles using an injection molding machine. If the polypropylene resin composition has an MFR of less than 5 g / 10 min, its moldability in injection molding is poor and it is unsuitable for use in automotive interior parts. If it exceeds 150 g / 10 min, its impact resistance is poor and it is unsuitable for use in automotive interior parts.

[0044] The molded article of the present invention is a molded article obtained by molding the polypropylene resin composition of the present invention by a known molding method, and examples thereof include an injection molded article, a press molded article, a vacuum molded article, a vacuum press molded article, a pressure molded article, a foam molded article, and an extrusion molded article.

[0045] The molded article of the present invention is preferably an injection-molded article, and examples of injection molding methods include general injection molding, injection foam molding, supercritical injection foam molding, ultra-high speed injection molding, injection compression molding, injection press molding, gas-assisted injection molding, sandwich molding, sandwich foam molding, and insert-outsert molding.

[0046] The molded article of the present invention is preferably used for automobile interior parts, such as door trims, pillars, instrument panels, consoles, rocker panels, armrests, door panels, and spare tire covers.

[0047] The molded article for automotive interior parts of the present invention can be produced by injection molding the polypropylene resin composition described above. The molding temperature is generally 150 to 350°C, preferably 170 to 250°C. A molding temperature exceeding 350°C can lead to deterioration of the resin composition and molding defects, while a molding temperature below 150°C can result in poor appearance and molding defects. The mold temperature is preferably in the range of 10 to 60°C. A mold temperature exceeding 60°C can produce molded articles with excellent surface finish and rigidity, but the molding cycle is lengthened, resulting in reduced productivity. Conversely, a mold temperature lower than 10°C can result in significant warpage and shrinkage, making it difficult to obtain satisfactory molded articles. Furthermore, condensation is more likely to form on the mold, which can accelerate mold corrosion. This is also unsuitable from the perspective of the energy costs associated with cooling. [Example]

[0048] The present invention will now be described with reference to examples, but is not limited to these examples. Unless otherwise specified, the blend amounts are expressed in parts by mass.

[0049] [Synthesis of fatty acid diethanolamide (D)] Synthesis Example 1 A glass autoclave was charged with 1,360 g of methyl laurate, 650 g of diethanolamine, and 19.6 g of 28% sodium methylate. The autoclave was purged with nitrogen and stirred. The pressure was reduced to below -0.090 MPa and the temperature was raised to 80°C. After heating, the reaction was carried out at below -0.090 MPa for 10 hours, followed by vacuum topping at 80°C for 4 hours, synthesizing 1,808 g of the target lauric acid diethanolamide (D1). The residual methanol in the product was 450 ppm. The residual methanol was measured according to Method 3 of the Quasi-drug Raw Materials Standards (External Drug Standards).

[0050] Fatty acid diethanolamides (D2) to (D5) were synthesized in the same manner as in Synthesis Example 1, except that the type of raw material fatty acid ester and the time of reduced pressure topping were changed as shown in Table 1. The amount of residual methanol is shown in Table 1. [Table 1]

[0051] [Manufacturing of injection molded products] Examples 1 to 9 and Comparative Examples 1 to 5 Using Novatec MA1B manufactured by Japan Polypropylene Corporation as polypropylene resin (A), the types and amounts of components (B) to (D) and other components shown in Tables 1 and 2 below were blended in a twin-screw extruder (TEM26SS manufactured by Toshiba Machine Co., Ltd.) and melt-kneaded (screw rotation speed: 250 rpm, cylinder temperature: 200°C). The extrudate was cooled and solidified with cold water and cut to obtain resin component compound pellets. The prepared compound was used in a hybrid injection molding machine FNX140 manufactured by Nissei Plastic Industrial Co., Ltd. at a molding temperature of 190°C to prepare flat test plates measuring 150 mm x 150 mm x 3 mm.

[0052] The measurements and evaluations of each evaluation item were carried out by the following methods. The results are shown in Tables 2 and 3.

[0053] (1) Evaluation of antistatic properties The test plate was left for 14 days at 23°C and 50% humidity, and then the surface resistivity was measured using a Hiresta UP MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. From past knowledge, the effective surface resistivity for preventing the adhesion of dirt and dust to molded products is 1 x 10 13 (logΩ / □) or less.

[0054] (2) Evaluation of anti-fogging properties Two 25mm x 100mm x 3mm pieces were cut from the test plate to serve as samples for evaluating fogging. The fogging evaluation was performed using a Thomas Scientific fogging tester (constant temperature oil bath) with the glass container heated to 100°C for 20 hours. After the heat treatment, the glass plate with the fogging was removed and left at 23°C and 50% humidity for 1 hour. The total light transmittance of the glass plate was measured using a Murakami Color Technology Research Co., Ltd. HM-150 L2 haze meter to evaluate the fogging prevention properties. Here, fogging that does not impair visibility while riding in a car was defined as less than 5%.

[0055] (3) Evaluation of bleeding properties The test piece was placed in an oven set at 60°C for 200 hours, and after being taken out, the appearance was visually observed and evaluated according to the following criteria. ○: No bleeding is visually observed △: Bleeding is visually observed ×: Bleeding was easily observed with the naked eye, and the composition was not practically usable.

[0056] (4) Acetaldehyde and formaldehyde emissions The amount of acetaldehyde emitted was measured by the following method using a test piece of 80 mm x 100 mm cut out from the flat molded article obtained in the above [Production of injection molded article]. (i) The test specimen was sealed in a 10 L sampling bag and filled with pure nitrogen gas. The pure nitrogen gas was then removed, and the gas in the sampling bag was replaced with nitrogen gas. This process was repeated twice. (ii) The sampling bag was filled with 4 L of pure nitrogen gas, and the tap of the sampling bag was closed. The sampling bag was placed in an oven, and a Teflon (registered trademark) sampling tube was attached to the tip of the tap and extended to the outside of the oven. In this state, the bag was heated at 65°C for 2 hours.

[0057] (iii) Sampling and measurement of acetaldehyde and formaldehyde After 1 L of the sample gas prepared in (ii) above was collected in a simulated adsorption tube heated to 65°C, the remaining sample gas was collected in its entirety on a 2,4-dinitrophenylhydrazine (DNPH) cartridge at a collection rate of 0.4 L / min. After collection, the cartridge was eluted with acetonitrile, and the components eluted from the cartridge were measured using a high-performance liquid chromatograph (HPLC; Waters, model: Ultra Performance Liquid Chromatography Aquiy).

[0058] The amount of acetaldehyde and formaldehyde emitted (the amount of acetaldehyde and formaldehyde emitted from one test piece of a specified size, unit: μg / test piece) was calculated using the calibration curve of the standard substance for the component. Note that the detection limit for acetaldehyde and formaldehyde in this evaluation method is 0.060 μg / test piece, and when the amount of acetaldehyde or formaldehyde emitted was 0.060 μg / test piece or less, it was recorded as "nd" (below the detection limit).

[0059] [Table 2]

[0060] [Table 3]

[0061] As shown in Table 2, all of the polypropylene resin compositions of Examples 1 to 9 were excellent in antistatic properties and anti-bleeding properties, and were also able to significantly suppress fogging and the generation of aldehydes. In contrast, as shown in Table 3, the polypropylene resin compositions of Comparative Examples 1 to 4 containing alkyldiethanolamine or fatty acid esters of alkyldiethanolamine exhibited fogging and generation of aldehydes.

Claims

1. For 100 parts by mass of the polypropylene resin (A), 0.05 to 0.5 parts by mass of monoglycerin fatty acid ester (B), 0.01 to 1.0 parts by mass of diglycerin fatty acid ester (C), and Lauric acid diethanolamide (D) 0.001 to 0.8 parts by mass A polypropylene resin composition comprising: A polypropylene-based resin composition characterized by being substantially free of alkyldiethanolamine and / or fatty acid ester of alkyldiethanolamine.

2. The polypropylene resin composition according to claim 1, which is substantially free of methanol derived from the component (D).

3. For 100 parts by mass of the polypropylene resin (A), 3. The polypropylene resin composition according to claim 1, wherein the components (B), (C) and (D) are blended in a total amount of 0.1 to 1.5 parts by mass.

4. 4. The polypropylene resin composition according to claim 1, wherein a mass ratio of the total of the components (B) and (C) to the component (D) is [(B) + (C)] / (D) = 1 / 99 to 99 / 1.

5. A molded article obtained by molding the polypropylene resin composition according to any one of claims 1 to 4.

6. An injection-molded article obtained by molding the polypropylene-based resin composition according to any one of claims 1 to 4.

7. A molded article for automobile interior parts obtained by molding the polypropylene resin composition according to any one of claims 1 to 4.

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