Asphalt composition and asphalt paving material composition

Abstract

To provide an asphalt composition and an asphalt pavement material composition that achieve superior hardness and heat resistance while improving the storage stability.SOLUTION: Disclosed is an asphalt composition including asphalt and a polyolefin copolymer containing monomeric units with epoxy groups, wherein the content of asphaltenes in the asphalt is less than 1 mass% relative to the total of the asphalt, and the proportion of the monomeric units with epoxy groups is 1-4 mass% relative to the total of the polyolefin copolymer.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an asphalt composition and an asphalt pavement material composition.

Background Art

[0002] For the paving of roads, parking lots, cargo yards, etc., asphalt paving using an asphalt composition is carried out because the laying is relatively easy and the time from the start of the paving work to the start of traffic is short. In recent years, from the perspective of the life cycle cost, the demand for high-durability paving has been increasing, and as a method for enhancing the durability of asphalt, an asphalt composition containing a high-strength and oil-resistant polyethylene resin has been studied (see, for example, Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] One aspect of the present invention relates to an asphalt composition and an asphalt pavement material composition that can achieve excellent hardness and heat resistance while improving storage stability.

Means for Solving the Problems

[0005] In some aspects of the present invention, the following [1] to [7] are provided. [1] An asphalt composition comprising asphalt and a polyolefin copolymer containing monomer units having epoxy groups, wherein the asphaltene content in the asphalt is less than 1% by mass relative to the total amount of the asphalt, and the proportion of monomer units having epoxy groups is 1 to 4% by mass relative to the total amount of the polyolefin copolymer. [2] The asphalt composition according to [1], wherein the MFR of the polyolefin copolymer at 190°C and 2.16 kg is 6 g / 10 min or more. [3] The asphalt composition according to [1] or [2], wherein the MFR of the polyolefin copolymer at 190°C and 2.16 kg is 40 g / 10 min or more. [4] The asphalt composition according to any one of [1] to [3], wherein the content of the polyolefin copolymer is 5 to 30 parts by mass per 100 parts by mass of asphalt. [5] The asphalt composition according to any one of [1] to [4], wherein the content of the polyolefin copolymer is 5 to 20 parts by mass per 100 parts by mass of asphalt. [6] The asphalt composition according to any one of [1] to [5], wherein the asphalt composition is a molten kneaded mixture containing the asphalt and the polyolefin copolymer. [7] An asphalt paving material composition comprising an asphalt composition described in any of [1] to [6] and aggregate. [Effects of the Invention]

[0006] According to one aspect of the present invention, an asphalt composition and an asphalt paving material composition are provided that can achieve excellent hardness and heat resistance while improving storage stability. [Modes for carrying out the invention]

[0007] The present invention is not limited to the examples described below.

[0008] An example of the asphalt composition of the present invention is an asphalt composition containing asphalt and a polyolefin copolymer containing monomer units having epoxy groups. The asphalt composition may also be a melted and kneaded mixture containing asphalt and a polyolefin copolymer containing monomer units having epoxy groups.

[0009] The asphalt is not particularly limited, but may include, for example, paving straight asphalt, natural asphalt such as lake asphalt, semi-blown asphalt, straight asphalt modified with blown asphalt, tar-modified straight asphalt, or a combination thereof.

[0010] The asphaltene content in asphalt is less than 1% by mass relative to the total amount of asphalt. A less than 1% by mass asphalt content suppresses gelation of the asphalt composition and provides excellent storage stability. From the viewpoint of even better storage stability, the asphaltene content in asphalt may be 0.5% by mass or less, 0.3% by mass or less, or 0.1% by mass or less. In this specification, the asphaltene content in asphalt refers to the value measured by the following procedure. First, 5g of asphalt is added to 100ml of n-heptane, and the n-heptane solution containing the asphalt is heated at 100°C for 1 hour with a reflux tubing attached. Next, the heated solution is filtered using a 200-mesh wire mesh, and the residue on the mesh is washed multiple times with heated n-heptane. Then, asphaltene is obtained by drying the residue, and the asphaltene content is calculated from the mass of the added asphalt and the mass of the obtained asphaltene.

[0011] The asphalt content may be 60% by mass or more, 65% by mass or more, 70% by mass or more, 75% by mass or more, or 80% by mass or more, based on the total mass of the asphalt composition, and may also be 99% by mass or less, 97% by mass or less, 95% by mass or less, 92% by mass or less, or 90% by mass or less.

[0012] A polyolefin copolymer containing monomer units having epoxy groups may be a copolymer comprising monomer units having epoxy groups and monomer units derived from ethylene and / or α-olefins. A polyolefin copolymer containing monomer units having epoxy groups may also be a polyethylene copolymer containing monomer units having epoxy groups. A polyolefin copolymer containing monomer units having epoxy groups may be a random copolymer or a block copolymer.

[0013] The monomer unit having an epoxy group may be, for example, a monomer unit derived from an unsaturated carboxylic acid glycidyl ester, or a monomer unit derived from a glycidyl ether having an unsaturated group.

[0014] The unsaturated carboxylic acid glycidyl ester may also be a compound represented by the following formula (1). In formula (1), R 1 This represents an alkenyl group having 2 to 18 carbon atoms, and the alkenyl group may have one or more substituents. Examples of compounds represented by formula (1) include glycidyl acrylate, glycidyl methacrylate, and glycidyl itaconic acid ester.

[0015] [ka]

[0016] A glycidyl ether having an unsaturated group may be a compound represented by the following formula (2). In formula (2), R 2 represents an alkenyl group having 2 to 18 carbon atoms, and the alkenyl group may have one or more substituents. X represents CH2-O or an oxygen atom. Examples of compounds represented by formula (2) include allyl glycidyl ether, 2-methylallyl glycidyl ether, and styrene-p-glycidyl ether.

[0017] [ka]

[0018] The proportion of monomer units having an epoxy group that constitute the polyolefin copolymer is 1 to 4% by mass based on the total amount of the polyolefin copolymer. When the proportion of monomer units having an epoxy group is 1% by mass or more based on the total amount of the polyolefin copolymer, the polyolefin copolymer containing monomer units having an epoxy group reacts with the functional groups of asphalt, thereby improving the affinity with asphalt and obtaining excellent storage stability. When the proportion of monomer units having an epoxy group is 4% by mass or less based on the total amount of the polyolefin copolymer, gelation of the asphalt composition due to excessive reaction between asphalt and the polyolefin copolymer containing monomer units having an epoxy group is suppressed, and excellent storage stability is obtained. From the viewpoint of further suppressing the gelation of the asphalt composition and having more excellent storage stability, the proportion of monomer units having an epoxy group may be 3.5% by mass or less, 3% by mass or less, 2.8% by mass or less, 2.6% by mass or less, or 2.5% by mass or less based on the total amount of the polyolefin copolymer. From the viewpoint of further improving the affinity with asphalt and having more excellent storage stability, the proportion of monomer units having an epoxy group may be 1.5% by mass or more, 1.8% by mass or more, 2% by mass or more, 2.2% by mass or more, or 2.3% by mass or more based on the total amount of the polyolefin copolymer.

[0019] The proportion of monomer units derived from ethylene and / or α-olefin that constitute the polyolefin copolymer (the total proportion of monomer units derived from ethylene and monomer units derived from α-olefin) may be 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 96% by mass or more, 96.5% by mass or more, 97% by mass or more, 97.2% by mass or more, 97.4% by mass or more, or 97.5% by mass or more, and may be 99% by mass or less, 98.5% by mass or less, 98.2% by mass or less, 98% by mass or less, 97.8% by mass or less, or 97.7% by mass or less.

[0020] The polyolefin copolymer containing a monomer unit having an epoxy group may contain monomer units such as styrene, acrylonitrile, unsaturated carboxylic acid esters (ethyl acrylate, methyl methacrylate, butyl acrylate, etc.), acrylic acid, and unsaturated vinyl esters (vinyl acetate, vinyl propionate, etc.) in addition to the monomer unit having an epoxy group, the monomer unit derived from ethylene and / or α-olefin.

[0021] Examples of the polyolefin copolymer containing a monomer unit having an epoxy group include ethylene-glycidyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-methyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-ethyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-normal propyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-isopropyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-norbutyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-isobutyl (meth)acrylate copolymer, and ethylene-glycidyl (meth)acrylate-vinyl acetate copolymer. The polyolefin copolymer containing a monomer unit having an epoxy group may be a polyolefin copolymer containing a monomer unit having a glycidyl group, may be a polyethylene copolymer containing a monomer unit having a glycidyl group, may be a polyethylene copolymer containing a monomer unit derived from glycidyl (meth)acrylate, or may be an ethylene-glycidyl (meth)acrylate copolymer. The ratio of the monomer unit having a glycidyl group and the monomer unit derived from glycidyl (meth)acrylate to the total amount of the polyolefin copolymer may be within the same range as the ratio of the monomer unit having an epoxy group described above. An example of a commercially available product of the ethylene-glycidyl (meth)acrylate copolymer is "Bondfast" (trade name) manufactured by Sumitomo Chemical.

[0022] Another example of a polyolefin copolymer containing monomer units having epoxy groups is glycidyl methacrylate-propylene copolymer.

[0023] Polyolefin copolymers containing monomer units having epoxy groups may be polymers obtained by graft polymerization of monomers having epoxy groups onto polyethylene, polypropylene, ethylene-α-olefin copolymers, hydrogenated and unhydrogenated styrene-conjugated diene polymers, etc., by solution or melt kneading.

[0024] The melt flow rate (MFR) of a polyolefin copolymer containing monomer units having epoxy groups at 190°C and 2.16 kg may be 1 g / 10 min or more, 3 g / 10 min or more, greater than 5 g / 10 min, 6 g / 10 min or more, 10 g / 10 min or more, 20 g / 10 min or more, 40 g / 10 min or more, 60 g / 10 min or more, 80 g / 10 min or more, 100 g / 10 min or more, 150 g / 10 min or more, or 180 g / 10 min or more. The MFR of a polyolefin copolymer containing monomer units having epoxy groups at 190°C and 2.16 kg may be 500 g / 10 min or less, 400 g / 10 min or less, 300 g / 10 min or less, or 200 g / 10 min or less. The MFR of a polyolefin copolymer containing monomer units with epoxy groups is a value measured according to JIS7210-1:2014, under conditions of 190°C and a load of 2.16 kg, using Method A (a method of calculating the extrusion rate in grams per 10 minutes (g / 10min) from the weight of the extruded product produced in a predetermined time).

[0025] The content of the polyolefin copolymer containing monomer units having epoxy groups may be 1 part by mass or more, 3 parts by mass or more, 5 parts by mass or more, 8 parts by mass or more, or 10 parts by mass or more per 100 parts by mass of asphalt, and may also be 40 parts by mass or less, 35 parts by mass or less, 30 parts by mass or less, 25 parts by mass or less, or 20 parts by mass or less. The content of the polyolefin copolymer containing monomer units having epoxy groups may be 1 to 40 parts by mass, 5 to 30 parts by mass, or 10 to 20 parts by mass per 100 parts by mass of asphalt.

[0026] An asphalt composition according to one embodiment may further contain components other than asphalt and a polyolefin copolymer containing monomer units having epoxy groups. The asphalt composition may further contain, for example, a polyethylene resin or a thermoplastic resin. However, among these resins, those that correspond to a polyolefin copolymer containing monomer units having epoxy groups shall be treated as a polyolefin copolymer containing monomer units having epoxy groups.

[0027] The heat resistance and durability of the asphalt composition can be improved by including a polyethylene resin. Examples of polyethylene resins include nonpolar polyethylene resins such as high-density polyethylene, low-density polyethylene, linear low-density polyethylene, linear ultra-low-density polyethylene (VLDPE), and ethylene-propylene copolymer; and polar polyethylene resins such as ionomer resins, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl acrylate copolymer (EMA), ethylene-methyl methacrylate copolymer (EMMA), and modified polyethylene resins (for example, reaction products of polyethylene resins with unsaturated carboxylic acids such as maleic acid and fumaric acid, acid anhydrides, esters, or metal salts). The polyethylene resin can be used alone or in combination of two or more types. The polyethylene resin may also include linear low-density polyethylene, VLDPE, EVA, and EMMA.

[0028] The polyethylene resin content may be 1 part by mass or more, 3 parts by mass or more, 5 parts by mass or more, or more than 5 parts by mass per 100 parts by mass of asphalt, and may also be 30 parts by mass or less, 20 parts by mass or less, less than 20 parts by mass, 15 parts by mass or less, or 10 parts by mass or less. The polyethylene resin content may be 1 to 30 parts by mass, 5 to 20 parts by mass, or more than 5 parts by mass but less than 20 parts by mass per 100 parts by mass of asphalt.

[0029] The asphalt composition can be improved in terms of heat resistance and durability by containing a thermoplastic resin. Examples of thermoplastic resins include styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, styrene-butadiene random copolymer, styrene-isoprene block copolymer, and styrene-isoprene random copolymer.

[0030] The content of thermoplastic resin may be 0.1 parts by mass or more, 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more per 100 parts by mass of asphalt, and may also be 10 parts by mass or less, 8 parts by mass or less, 6 parts by mass or less, or 5 parts by mass or less. The content of thermoplastic resin may be 0.1 to 10 parts by mass, or 2 to 6 parts by mass per 100 parts by mass of asphalt.

[0031] An asphalt composition can be obtained by melt-kneading a mixture containing asphalt and a polyolefin copolymer containing monomer units having epoxy groups. The order in which the resin, such as the polyolefin copolymer containing monomer units having epoxy groups, is added to the asphalt is not particularly limited. For example, if the asphalt composition contains a polyolefin copolymer containing monomer units having epoxy groups and a polyethylene resin, the polyolefin copolymer containing monomer units having epoxy groups and the polyethylene resin may be kneaded beforehand, and then the resulting mixture may be melt-kneaded with asphalt. Alternatively, the asphalt and the polyolefin copolymer containing monomer units having epoxy groups may be kneaded beforehand, and then the resulting mixture may be melt-kneaded with the polyethylene resin. If the asphalt composition contains a thermoplastic resin, the asphalt, the polyolefin copolymer containing monomer units having epoxy groups, and the thermoplastic resin may be kneaded beforehand, and then the resulting mixture may be melt-kneaded with the polyethylene resin. The temperature during melt-kneading may be, for example, 100 to 250°C or 150 to 200°C. The time for melt-kneading may be, for example, 0.01 to 6 hours.

[0032] The asphalt composition can be used, for example, in combination with aggregate, and can be used as an asphalt composition for road paving containing the asphalt composition and aggregate. The aggregate may be added during the process of manufacturing the asphalt composition. That is, another embodiment of the present invention is an asphalt paving material composition (asphalt composition for road paving) containing the asphalt composition and aggregate.

[0033] The type and content of aggregate can be adjusted as appropriate within the range commonly used in the field of road paving. Examples of aggregates include crushed stone and crushed sand, and crushed stone and crushed sand of sedimentary rock (e.g., hard sandstone, limestone). The aggregate content may be, for example, 1,000 to 10,000 parts by mass per 100 parts by mass of asphalt composition. [Examples]

[0034] The present invention is not limited to the following embodiments.

[0035] 1. Raw materials (1) Asphalt (StAs) • Straight asphalt 1: Penetration: 70, Asphaltene content: 0.1% by mass or less • Straight Asphalt 2: Penetration: 60, Asphaltene Content: 0.5% by mass • Straight Asphalt 3: Penetration: 35, Asphaltene Content: 1.0% by mass • Straight Asphalt 4: Penetration: 10, Asphaltene Content: 3.0% by mass • Straight Asphalt 5: Penetration: 5, Asphaltene Content: 6.0% by mass (2) Additives Polyolefin copolymer containing monomer units having epoxy groups • BF-30C: Ethylene / glycidyl methacrylate copolymer (hereinafter also referred to as "EGMA copolymer"), manufactured by Sumitomo Chemical Co., Ltd., monomer unit content derived from glycidyl methacrylate: 19% by mass, MFR 7g / 10 min (190℃, 2.16kg load) • BF-2C: EGMA copolymer, manufactured by Sumitomo Chemical Co., Ltd., monomer unit content derived from glycidyl methacrylate: 6% by mass, MFR 3g / 10min (190℃, 2.16kg load) • BF1: EGMA copolymer, manufactured by Sumitomo Chemical Co., Ltd., monomer unit content derived from glycidyl methacrylate: 2.3% by mass, MFR 44g / 10min (190℃, 2.16kg load) • BF2: EGMA copolymer, manufactured by Sumitomo Chemical Co., Ltd., monomer unit content derived from glycidyl methacrylate: 2.3% by mass, MFR 83g / 10min (190℃, 2.16kg load) • BF3: EGMA copolymer, manufactured by Sumitomo Chemical Co., Ltd., monomer unit content derived from glycidyl methacrylate: 2.5% by mass, MFR 180g / 10min (190℃, 2.16kg load) • BF4: EGMA copolymer, manufactured by Sumitomo Chemical Co., Ltd., monomer unit content derived from glycidyl methacrylate: 2.4% by mass, MFR 3g / 10min (190℃, 2.16kg load) • BF-7L: Ethylene / glycidyl methacrylate / methyl acrylate copolymer (hereinafter also referred to as "EGMAMA copolymer"), manufactured by Sumitomo Chemical Co., Ltd., monomer unit content derived from glycidyl methacrylate: 3% by mass, monomer unit content derived from methyl acrylate: 27% by mass, MFR 7g / 10min (190℃, 2.16kg load) • BF5: EGMAMA copolymer, manufactured by Sumitomo Chemical Co., Ltd., monomer unit content derived from glycidyl methacrylate: 1.5% by mass, monomer unit content derived from methyl acrylate: 27% by mass, MFR 7g / 10min (190℃, 2.16kg load) Other additives • L420: Low-density polyethylene, manufactured by Sumitomo Chemical Co., Ltd., MFR 3.5g / 10min (190℃, 2.16kg load) • G806: Low-density polyethylene, manufactured by Sumitomo Chemical Co., Ltd., MFR 50g / 10min (190℃, 2.16kg load) • SBS: Styrene / butadiene / styrene copolymer, manufactured by Asahi Kasei Corporation, T437L

[0036] 2. Preparation of the asphalt composition (Examples 1-16, Comparative Examples 1-11) 400g of StAs was heated in an oven at 180°C for 30 minutes. A homomixer MARK II 2.5 type stirring section was inserted into the softened StAs, and the additive was added while gradually increasing the rotation speed of the stirring section. Next, the mixture was melt-kneaded at 4000 rpm for 1 hour while heating to 180°C. The formed molten mixture was cooled to room temperature over 24 hours to obtain the asphalt composition. The amount of additive added was adjusted to the amounts shown in Tables 1 and 2 (amount per 100 parts by mass of asphalt; unit: parts by mass). The asphalt compositions obtained in Comparative Examples 2 and 11 were deemed unsuitable for evaluation due to undissolved additive residue.

[0037] 3. Evaluation (penetration) In accordance with JIS K2207, the penetration of the prepared asphalt composition was measured at 25°C using it as a test specimen. The penetration values ​​in the table are expressed in units of 1 / 10 mm, representing the penetration depth of a standard needle.

[0038] (softening point) The softening point (in °C) of the asphalt composition was measured by the Mettler Cup-and-Ball Method according to ASTM D3461-14.

[0039] (viscosity) The viscosity (in cP) of the asphalt composition was measured using a rotational viscometer in accordance with JPI-5S-54-99.

[0040] (Storage stability) The prepared asphalt composition was placed in an aluminum can and stored in an oven at 175°C for one day. After storage, the asphalt composition in the aluminum can was stirred with a spatula. If no lumps, phase separation, or gelation were observed, the storage stability was evaluated as "A". If lumps were observed, the storage stability was evaluated as "B". If phase separation was observed, the storage stability was evaluated as "C". If gelation was observed, the storage stability was evaluated as "D".

[0041] [Table 1]

[0042] [Table 2]

[0043] Tables 1-3 show that, by comparing Examples 1-16 with Comparative Examples 1-11, it was confirmed that the asphalt composition containing a polyolefin copolymer with monomer units having epoxy groups improves the storage stability of the asphalt composition while achieving excellent hardness and heat resistance.

Claims

1. It contains asphalt and a polyolefin copolymer containing monomer units having epoxy groups, The asphalt content in the asphalt is less than 1% by mass relative to the total amount of the asphalt. The proportion of monomer units having epoxy groups is 1 to 4% by mass relative to the total amount of the polyolefin copolymer. An asphalt composition wherein the polyolefin copolymer has an MFR of 40 g / 10 min or more at 190°C and 2.16 kg.

2. The asphalt composition according to claim 1, wherein the content of the polyolefin copolymer is 5 to 30 parts by mass per 100 parts by mass of asphalt.

3. The asphalt composition according to claim 1 or 2, wherein the content of the polyolefin copolymer is 5 to 20 parts by mass per 100 parts by mass of asphalt.

4. The asphalt composition according to claim 1 or 2, wherein the asphalt composition is a molten kneaded mixture containing the asphalt and the polyolefin copolymer.

5. An asphalt paving material composition comprising the asphalt composition according to claim 1 or 2 and aggregate.

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