Aqueous dispersion, surface treatment agent, treated fiber and treated filler

Abstract

To provide an aqueous dispersion, a surface treatment agent, a treated fiber and a treated filler having a relatively low yellowness degree.SOLUTION: There is provided an aqueous dispersion which contains an acid-modified polypropylene wax obtained by modifying a polypropylene-based wax with an acid and water for dispersing the acid-modified polypropylene wax. The acid includes unsaturated dicarboxylic acids. The acid-modified polypropylene wax contains a propylene-derived structural unit in a ratio of 80 mass % or more based on the total amount of the acid-modified polypropylene wax. The acid-modified polypropylene wax has a weight average molecular weight of 5000 or more and 50000 or less. The acid-modified polypropylene wax has an acid value of 1 mgKOH / g or more and 200 mgKOH / g or less. The acid-modified polypropylene wax has a color hue APHA of 500 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to aqueous dispersions, surface treatment agents, treated fibers, and treated fillers. [Background technology]

[0002] Conventionally, aqueous dispersions of polypropylene-based resins have been known as fiber treatment agents. More specifically, for example, the following sizing agent for inorganic fibers is known. This sizing agent for inorganic fibers is composed of an aqueous emulsion containing a polypropylene-based resin (A) or a salt thereof. The polypropylene-based resin (A) is obtained by modifying a low-molecular-weight polypropylene-based resin (B) having a number-average molecular weight of 500 to 20,000 with an unsaturated dicarboxylic acid (C) (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-107442 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, aqueous dispersions of polypropylene resins are required to have low yellowness depending on their applications, but the above-mentioned sizing agents for inorganic fibers have the disadvantage of having relatively high yellowness.

[0005] The present invention is an aqueous dispersion, a surface treatment agent, a treated fiber, and a treated filler having a relatively low yellowness. [Means for solving the problem]

[0006] The present invention [1] includes an aqueous dispersion containing an acid-modified polypropylene wax obtained by modifying a polypropylene wax with an acid, and water in which the acid-modified polypropylene wax is dispersed, wherein the acid contains an unsaturated dicarboxylic acid, the acid-modified polypropylene wax contains structural units derived from propylene in a proportion of 80 mass% or more relative to the total amount of the acid-modified polypropylene wax, the weight-average molecular weight of the acid-modified polypropylene wax is 5,000 or more and 50,000 or less, the acid value of the acid-modified polypropylene wax is 1 mgKOH / g or more and 200 mgKOH / g or less, and the color APHA of the acid-modified polypropylene wax is 500 or less.

[0007] The present invention [2] includes the aqueous dispersion according to the above [1], in which the ash content of the acid-modified polypropylene wax is 100 ppm or less.

[0008] The present invention [3] includes the aqueous dispersion according to the above [1] or [2], in which the acid-modified polypropylene wax has a phosphorus content of 10 ppm or less.

[0009] The present invention [4] includes the aqueous dispersion according to any one of the above [1] to [3], in which the calcium content of the acid-modified polypropylene wax is 10 ppm or less.

[0010] The present invention [5] includes the aqueous dispersion according to any one of the above [1] to [4], in which the acid-modified polypropylene wax has a free acid content of 200 ppm or less.

[0011] The present invention [6] includes a surface treatment agent containing the aqueous dispersion according to any one of the above [1] to [5].

[0012] The present invention [7] includes a treated fiber comprising a fiber and a dried product of the surface treatment agent described in [6] above, which coats at least a portion of the fiber.

[0013] The present invention [8] includes a treated filler comprising a filler and the dried product of the surface treatment agent described in [6] above, which coats at least a portion of the filler. [Effects of the Invention]

[0014] The aqueous dispersion of the present invention has a relatively low yellowness.

[0015] The surface treatment agent of the present invention has a relatively low yellowness because it contains the above-mentioned aqueous dispersion.

[0016] The treated fiber and treated filler of the present invention have a relatively low yellowness because they contain the dried product of the above-mentioned aqueous dispersion. DETAILED DESCRIPTION OF THE INVENTION

[0017] 1. Water dispersion The aqueous dispersion of the present invention contains an acid-modified polypropylene wax and water in which the acid-modified polypropylene wax is dispersed.

[0018] As will be described later, the acid-modified polypropylene wax is obtained by modifying an unmodified polypropylene wax with an acid. That is, the acid-modified polypropylene wax is an acid-modified product of an unmodified polypropylene wax.

[0019] The unmodified polypropylene wax may be simply referred to as a polypropylene wax.

[0020] The polypropylene wax is a polypropylene resin having a relatively low molecular weight, which can be obtained, for example, by short-chain decomposition (described later) of a polypropylene resin having a relatively high molecular weight (raw polypropylene resin).

[0021] A polypropylene resin having a relatively low molecular weight may be simply referred to as a low-molecular-weight polypropylene resin, and a polypropylene resin having a relatively high molecular weight may be simply referred to as a high-molecular-weight polypropylene resin.

[0022] The high molecular weight polypropylene resin (raw polypropylene resin), the low molecular weight polypropylene resin (polypropylene wax), and the acid-modified polypropylene wax will be described in detail below.

[0023] (1) High molecular weight polypropylene resin (raw polypropylene resin) High molecular weight polypropylene resin is a polypropylene resin with a relatively high molecular weight. "Relatively high molecular weight" means that the weight average molecular weight (molecular weight in polypropylene equivalent) exceeds 50,000. High molecular weight polypropylene resin is a raw material polypropylene resin for producing low molecular weight polypropylene resin.

[0024] More specifically, the high-molecular-weight polypropylene resin is a high-molecular-weight polymer of an olefin component containing propylene. The olefin component contains propylene as an essential component. In addition, in the high-molecular-weight polypropylene resin, the olefin component can optionally contain an olefin other than propylene. Examples of olefins other than propylene include ethylene and α-olefins having 4 or more carbon atoms. Examples of α-olefins having 4 or more carbon atoms include α-olefins having 4 to 20 carbon atoms, more specifically 1-brene, isobutene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, and 1-dodecene. These may be used alone or in combination of two or more. Furthermore, the olefin component may optionally contain a vinyl compound. Examples of vinyl compounds include unsaturated monocarboxylic acids and unsaturated monocarboxylic acid alkyl esters. These may be used alone or in combination of two or more.

[0025] In the high-molecular-weight polypropylene-based resin, the olefin component preferably consists of propylene, or consists of propylene and ethylene, or consists of propylene and an α-olefin having 4 or more carbon atoms. The olefin component more preferably consists of propylene or consists of propylene and ethylene. The olefin component further preferably consists of propylene and ethylene.

[0026] The propylene content relative to the total amount of olefin components is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and for example, 100% by mass or less, preferably 99% by mass or less, more preferably 98% by mass or less, relative to the total amount of olefin components.

[0027] In other words, the content of structural units derived from propylene relative to the total amount of the high molecular weight polypropylene-based resin is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more. Furthermore, the content of structural units derived from propylene relative to the total amount of the high molecular weight polypropylene-based resin is, for example, 100% by mass or less, preferably 99% by mass or less, more preferably 98% by mass or less. The content of structural units derived from propylene is, in accordance with the examples described later, 13 It is measured by C-NMR (same below).

[0028] The content of ethylene and / or α-olefins having 4 or more carbon atoms relative to the total amount of olefin components is, for example, 0% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more. The content of ethylene and / or α-olefins having 4 or more carbon atoms relative to the total amount of olefin components is, for example, 20% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less.

[0029] In other words, the content of structural units derived from ethylene and / or α-olefins having 4 or more carbon atoms relative to the total amount of the high molecular weight polypropylene resin is, for example, 0% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more. Furthermore, the content of structural units derived from ethylene and / or α-olefins having 4 or more carbon atoms relative to the total amount of the high molecular weight polypropylene resin is, for example, 20% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less. The content of structural units derived from ethylene and / or α-olefins having 4 or more carbon atoms is, in accordance with the examples described later, 13 It is measured by C-NMR (same below).

[0030] The high-molecular-weight polypropylene resin can be obtained by polymerizing an olefin component by a known method, and is also available as a commercially available product.

[0031] The weight average molecular weight (Mw) (polypropylene equivalent molecular weight) of the high molecular weight polypropylene resin is, for example, more than 50,000, preferably 100,000 or more, more preferably 200,000 or more. The weight average molecular weight (Mw) (polypropylene equivalent molecular weight) of the high molecular weight polypropylene resin is, for example, 500,000 or less, preferably 400,000 or less.

[0032] The number average molecular weight (Mn) (polypropylene equivalent molecular weight) of the high molecular weight polypropylene resin is, for example, 10,000 or more, preferably 20,000 or more, and more preferably 40,000 or more. The number average molecular weight (Mn) (polypropylene equivalent molecular weight) of the high molecular weight polypropylene resin is, for example, 100,000 or less, preferably 80,000 or less, and more preferably 60,000 or less.

[0033] The weight average molecular weight and number average molecular weight are measured by gel permeation chromatography (GPC) in accordance with the examples described below (the same applies hereinafter).

[0034] The polydispersity (Mw / Mn) of the high molecular weight polypropylene resin is, for example, 1.5 or more, preferably 2.0 or more, more preferably 2.5 or more, and for example, 20.0 or less, preferably 10.0 or less, more preferably 8.0 or less.

[0035] The high molecular weight polypropylene resin has an MFR (Melt flow rate) of, for example, 10 g / 10 min or more, preferably 30 g / 10 min or more, more preferably 40 g / 10 min or more, and an MFR (Melt flow rate) of, for example, 100 g / 10 min or less, preferably 80 g / 10 min or less, more preferably 60 g / 10 min or less.

[0036] (2) Low molecular weight polypropylene resin (polypropylene wax) The low-molecular-weight polypropylene resin (polypropylene wax) is a polypropylene resin having a relatively low molecular weight. The term "relatively low molecular weight" refers to a weight-average molecular weight (molecular weight in terms of polypropylene) of 50,000 or less, preferably 20,000 or less.

[0037] More specifically, polypropylene wax is a low-molecular-weight polymer of an olefin component containing propylene. The olefin component contains propylene as an essential component. The olefin component may also contain an olefin other than propylene as an optional component. Examples of olefins other than propylene include the above-mentioned ethylene and the above-mentioned α-olefins having 4 or more carbon atoms. The olefin component may also contain the above-mentioned vinyl compound as an optional component. These may be used alone or in combination of two or more types.

[0038] In the polypropylene-based wax, the olefin component preferably consists of propylene, or consists of propylene and ethylene, or consists of propylene and an α-olefin having 4 or more carbon atoms. The olefin component more preferably consists of propylene or consists of propylene and ethylene. The olefin component further preferably consists of propylene and ethylene.

[0039] The propylene content relative to the total amount of olefin components is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and for example, 100% by mass or less, preferably 99% by mass or less, more preferably 98% by mass or less, relative to the total amount of olefin components.

[0040] In other words, the content of structural units derived from propylene relative to the total amount of the polypropylene wax is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more. Furthermore, the content of structural units derived from propylene relative to the total amount of the polypropylene wax is, for example, 100% by mass or less, preferably 99% by mass or less, more preferably 98% by mass or less. The content of structural units derived from propylene is determined based on the examples described later. 13 It is measured by C-NMR (same below).

[0041] The content of ethylene and / or α-olefins having 4 or more carbon atoms relative to the total amount of olefin components is, for example, 0% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more. The content of ethylene and / or α-olefins having 4 or more carbon atoms relative to the total amount of olefin components is, for example, 20% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less.

[0042] In other words, the content of structural units derived from ethylene and / or α-olefins having 4 or more carbon atoms relative to the total amount of the polypropylene wax is, for example, 0% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more. Furthermore, the content of structural units derived from ethylene and / or α-olefins having 4 or more carbon atoms relative to the total amount of the polypropylene wax is, for example, 20% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less. The content of structural units derived from ethylene and / or α-olefins having 4 or more carbon atoms is, in accordance with the examples described later, 13 It is measured by C-NMR (same below).

[0043] When the olefin component of the polypropylene wax is composed of propylene and ethylene, the ethylene content relative to the total amount of the olefin components is, for example, 0% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, and the ethylene content relative to the total amount of the olefin components is, for example, 20% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less.

[0044] The polypropylene wax can be obtained by short-chain decomposition of a high-molecular-weight polypropylene resin, for example, by thermal decomposition.

[0045] The method for thermally decomposing the high-molecular-weight polypropylene-based resin is not particularly limited, and known methods can be used. For example, the high-molecular-weight polypropylene-based resin is heated under an inert gas atmosphere. The heating temperature for thermal decomposition is, for example, 300°C or higher and 450°C or lower. The heating time for thermal decomposition is, for example, 5 hours or higher and 20 hours or lower. The heating time varies greatly depending on the equipment used for thermal decomposition. From the viewpoint of suppressing coloration of the polypropylene-based wax, the heating time is preferably as short as possible.

[0046] This results in a polypropylene wax being obtained as a short-chain product of a high-molecular-weight polypropylene resin. The polypropylene wax is also available as a commercial product.

[0047] The weight average molecular weight (Mw) (polypropylene equivalent molecular weight) of the polypropylene wax is, for example, 1500 or more, preferably 3000 or more, more preferably 6500 or more, and even more preferably 8000 or more. The weight average molecular weight (Mw) (polypropylene equivalent molecular weight) of the polypropylene wax is, for example, 20000 or less, preferably 15000 or less, more preferably 10000 or less, and even more preferably 9000 or less.

[0048] The number average molecular weight (Mn) of the polypropylene wax (molecular weight in terms of polypropylene) is, for example, 500 or more, preferably 1000 or more, more preferably 1500 or more, and even more preferably 1800 or more. The number average molecular weight (Mn) of the polypropylene wax (molecular weight in terms of polypropylene) is, for example, 10000 or less, preferably 5000 or less, more preferably 3000 or less, and even more preferably 2500 or less.

[0049] The polypropylene wax has a polydispersity (Mw / Mn) of, for example, 1.5 or more, preferably 2.0 or more, more preferably 2.5 or more, and even more preferably 3.0 or more. The polypropylene wax has a polydispersity (Mw / Mn) of, for example, 20.0 or less, preferably 10.0 or less, more preferably 8.0 or less, and even more preferably 6.0 or less.

[0050] The density of polypropylene wax is, for example, 800 kg / cm 3 More than 820 kg / cm 3 More preferably, 850 kg / cm 3 The density of the polypropylene wax is, for example, 950 kg / cm 3 Preferably, 930 kg / cm or less 3or less, more preferably 900 kg / cm 3 The density is measured in accordance with the examples described below (the same applies hereinafter).

[0051] The softening point of the polypropylene wax is, for example, 100° C. or higher, preferably 130° C. or higher, and more preferably 140° C. or higher. The softening point of the polypropylene wax is, for example, 180° C. or lower, preferably 150° C. or lower, and more preferably 148° C. or lower. The softening point is measured in accordance with the examples described later (the same applies hereinafter).

[0052] The polypropylene wax has a melt viscosity at 180°C of, for example, 40 mPa·s or more, preferably 55 mPa·s or more, and more preferably 65 mPa·s or more. The polypropylene wax has a melt viscosity at 180°C of, for example, 200 mPa·s or less, preferably 100 mPa·s or less, and more preferably 80 mPa·s or less. The melt viscosity at 180°C is measured in accordance with the examples described later (the same applies hereinafter).

[0053] The hue APHA of the polypropylene wax is, for example, 100 or less, preferably 90 or less, and more preferably 70 or less. The hue APHA of the polypropylene wax is usually 1 or more. The hue APHA is measured in accordance with the examples described later (the same applies hereinafter).

[0054] (3) Acid-modified polypropylene wax The acid-modified polypropylene wax is a modified product obtained by modifying a polypropylene wax with an acid.

[0055] The acid contains an unsaturated dicarboxylic acid. The acid is preferably composed of an unsaturated dicarboxylic acid. Examples of unsaturated dicarboxylic acids include unsaturated dicarboxylic acids and their esters, preferably unsaturated dicarboxylic acids. Examples of unsaturated dicarboxylic acids include maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, and anhydrides thereof. These can be used alone or in combination of two or more. A preferred example of the unsaturated dicarboxylic acid is maleic acid.

[0056] The method for modifying the polypropylene wax with an acid is not particularly limited, but for example, the polypropylene wax is reacted with an acid in the presence of a known catalyst.

[0057] Examples of catalysts include radical generators. Radical generators are not particularly limited, but include, for example, hydrogen peroxide, persulfates, peroxides, azo compounds, and redox initiators. Examples of persulfates include ammonium persulfate, potassium persulfate, and sodium persulfate. Examples of peroxides include cumene hydroperoxide, di-t-butyl peroxide, t-butyl hydroperoxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butyl peroxybenzoate, and lauroyl peroxide. Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and 1,1'-azobis(cyclohexane-1-carbonitrile). These can be used alone or in combination of two or more. A preferred catalyst is a peroxide, and more preferably di-t-butyl peroxide. The blending ratio of the catalyst is not particularly limited and may be appropriately set depending on the purpose and application.

[0058] The blending ratio of the polypropylene wax and the acid is adjusted so that the weight average molecular weight of the acid-modified polypropylene wax falls within the range described below, and the acid value of the acid-modified polypropylene wax falls within the range described below.

[0059] More specifically, the amount of acid is, for example, 1 part by mass or more, preferably 3 parts by mass or more, per 100 parts by mass of polypropylene wax. If the proportion of acid is above the lower limit, excellent water dispersibility is obtained. In other words, the particle size of the acid-modified polypropylene wax in water can be made relatively small. Therefore, excellent storage stability is obtained. Furthermore, the amount of acid is, for example, 20 parts by mass or less, preferably 10 parts by mass or less, per 100 parts by mass of polypropylene wax. If the proportion of acid is below the upper limit, the softening point of the acid-modified polypropylene wax can be made relatively high, and a resin composition (for example, the treated fiber and treated filler described below) with excellent strength can be obtained.

[0060] Furthermore, the polypropylene wax is, for example, 80% by mass or more, preferably 90% by mass or more, based on the total amount of the polypropylene wax and the acid. If the proportion of the polypropylene wax exceeds the above lower limit, the softening point of the acid-modified polypropylene wax can be relatively high, resulting in a resin composition with excellent strength (for example, the treated fiber and treated filler described below). Furthermore, the polypropylene wax is, for example, 99% by mass or less, preferably 97% by mass or less, based on the total amount of the polypropylene wax and the acid. If the proportion of the polypropylene wax is below the above upper limit, excellent water dispersibility can be obtained. In other words, the particle size of the acid-modified polypropylene wax in water can be relatively small. Therefore, excellent storage stability can be obtained.

[0061] Furthermore, the amount of acid is, for example, 0.1% by mass or more, preferably 3% by mass or more, based on the total amount of the polypropylene wax and the acid. If the proportion of acid is above the lower limit, excellent water dispersibility is obtained. In other words, the particle size of the acid-modified polypropylene wax in water can be made relatively small. Therefore, excellent storage stability is obtained. Furthermore, the amount of acid is, for example, 20% by mass or less, preferably 10% by mass or less, based on the total amount of the polypropylene wax and the acid. If the proportion of acid is below the upper limit, the softening point of the acid-modified polypropylene wax can be made relatively high, resulting in a resin composition (for example, the treated fiber and treated filler described below) with excellent strength.

[0062] In the reaction between the polypropylene wax and the acid, a melt method or a solution method may be adopted.

[0063] In the melting method, for example, a mixture of polypropylene wax and acid is melted and kneaded in the presence of a catalyst. This causes the polypropylene wax and acid to react with each other. The reaction temperature is, for example, 120°C or higher, preferably 150°C or higher. If the reaction temperature is higher than the lower limit, the polypropylene wax can be melted relatively uniformly. Therefore, the acid and polypropylene wax can react relatively uniformly. As a result, an acid-modified polypropylene wax with excellent water dispersibility is obtained. The reaction temperature is, for example, 300°C or lower, preferably 200°C or lower. If the reaction temperature is lower than the upper limit, discoloration of the acid-modified polypropylene wax can be more effectively suppressed. The reaction time is, for example, 30 minutes or longer, preferably 1 hour or longer. If the reaction time is higher than the lower limit, the polypropylene wax can be melted relatively uniformly. Therefore, the acid and polypropylene wax can react relatively uniformly. As a result, an acid-modified polypropylene wax with excellent water dispersibility is obtained. The reaction time is, for example, 24 hours or shorter, preferably 12 hours or shorter. If the reaction time is below the upper limit, coloration of the acid-modified polypropylene wax can be more effectively suppressed.

[0064] In the solution method, for example, a polypropylene wax and an acid are dissolved in a known organic solvent and heated and mixed in the presence of a catalyst. This causes the polypropylene wax and the acid to react with each other. Examples of organic solvents include hydrocarbons and halogenated hydrocarbons. The reaction temperature is, for example, 80°C or higher, preferably 100°C or higher. If the reaction temperature is higher than the lower limit, the polypropylene wax can be melted relatively uniformly. Therefore, the acid and the polypropylene wax can react relatively uniformly. As a result, an acid-modified polypropylene wax with excellent water dispersibility is obtained. The reaction temperature is, for example, 300°C or lower, preferably 200°C or lower. If the reaction temperature is lower than the upper limit, discoloration of the acid-modified polypropylene wax can be more effectively suppressed. The reaction time is, for example, 30 minutes or longer, preferably 1 hour or longer. If the reaction time is higher than the lower limit, the polypropylene wax can be melted relatively uniformly. Therefore, the acid and the polypropylene wax can react relatively uniformly. As a result, an acid-modified polypropylene wax with excellent water dispersibility is obtained. The reaction time is, for example, 24 hours or less, preferably 12 hours or less. If the reaction time is less than the above upper limit, coloration of the acid-modified polypropylene wax can be more effectively suppressed.

[0065] As a result, an acid-modified polypropylene wax is obtained as a reaction product of the polypropylene wax and the acid.

[0066] That is, the acid-modified polypropylene wax is a reaction product of a polypropylene wax (a polymer of an olefin component) and a raw material component containing the above-mentioned acid. In other words, the acid-modified polypropylene wax is a reaction product of a polymer of an olefin component and a raw material component containing an acid.

[0067] The content of the structural units derived from propylene relative to the total amount of the acid-modified polypropylene wax is, for example, 80% by mass or more, preferably 90% by mass or more, and more preferably 95% by mass or more. If the content of the structural units derived from propylene is above the lower limit, the softening point of the acid-modified polypropylene wax can be relatively high, resulting in a resin composition with excellent strength (for example, the treated fiber and treated filler described below). Furthermore, the content of the structural units derived from propylene relative to the total amount of the acid-modified polypropylene wax is, for example, 99.9% by mass or less, preferably 99% by mass or less, and more preferably 98% by mass or less. If the content of the structural units derived from propylene is below the upper limit, excellent water dispersibility can be obtained. In other words, the particle size of the acid-modified polypropylene wax in water can be relatively small. Therefore, excellent storage stability can be obtained. The content of the structural units derived from propylene is determined based on the examples described below. 13 It is measured by C-NMR (same below).

[0068] Furthermore, the content of structural units derived from ethylene and / or α-olefins having 4 or more carbon atoms relative to the total amount of the acid-modified polypropylene wax is, for example, 0% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more. Furthermore, the content of structural units derived from ethylene and / or α-olefins having 4 or more carbon atoms relative to the total amount of the acid-modified polypropylene wax is, for example, 20% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less. If the content of structural units derived from ethylene and / or α-olefins having 4 or more carbon atoms is below the upper limit, the softening point of the acid-modified polypropylene wax can be relatively high, resulting in a resin composition with excellent strength (for example, treated fibers and treated fillers described later). The content of structural units derived from ethylene and / or α-olefins having 4 or more carbon atoms can be, for example, 0% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, based on the total amount of the acid-modified polypropylene wax. 13 It is measured by C-NMR (same below).

[0069] Furthermore, the content ratio of the structural units derived from the acid relative to the total amount of the acid-modified polypropylene wax is, for example, 0.1% by mass or more, preferably 1% by mass or more, and more preferably 2% by mass or more. If the content ratio of the structural units derived from the acid is above the lower limit, excellent water dispersibility can be obtained. In other words, the particle size of the acid-modified polypropylene wax in water can be made relatively small. Therefore, excellent storage stability can be obtained. Furthermore, the content ratio of the structural units derived from the acid relative to the total amount of the acid-modified polypropylene wax is, for example, 20% by mass or less, preferably 10% by mass or less, and more preferably 5% by mass or less. If the content ratio of the structural units derived from the acid is below the upper limit, the softening point of the acid-modified polypropylene wax can be made relatively high, and therefore a resin composition (for example, the treated fiber and treated filler described below) with excellent strength can be obtained.

[0070] The acid value of the acid-modified polypropylene wax is 1 mgKOH / g or more, preferably 10 mgKOH / g or more, more preferably 20 mgKOH / g or more, even more preferably 30 mgKOH / g or more, even more preferably 40 mgKOH / g or more, and particularly preferably 48 mgKOH / g or more. If the acid value of the acid-modified polypropylene wax is below the above lower limit, the dispersibility in water decreases, resulting in an increase in the particle size of the polypropylene wax in water and a decrease in storage stability. In addition, the acid value of the acid-modified polypropylene wax is 200 mgKOH / g or less, preferably 150 mgKOH / g or less, more preferably 100 mgKOH / g or less, even more preferably 80 mgKOH / g or less, and particularly preferably 50 mgKOH / g or less. If the acid value of the acid-modified polypropylene wax exceeds the above range, the softening point of the acid-modified polypropylene wax decreases, resulting in a decrease in the strength of the resin composition (for example, the treated fiber and treated filler described below).

[0071] The weight-average molecular weight (Mw) (polypropylene-equivalent molecular weight) of the acid-modified polypropylene wax is 5,000 or more, preferably 10,000 or more, more preferably 20,000 or more, and even more preferably 25,000 or more. If the weight-average molecular weight (Mw) of the acid-modified polypropylene wax is below the lower limit, the coverage of the treated fiber (described below) and the treated filler (described below) is improved, but the acid-modified polypropylene wax becomes embrittled, resulting in a decrease in the strength of the resin composition (e.g., the treated fiber and treated filler described below). The weight-average molecular weight (Mw) (polypropylene-equivalent molecular weight) of the acid-modified polypropylene wax is 50,000 or less, preferably 40,000 or less, more preferably 35,000 or less, and even more preferably 30,000 or less. If the weight-average molecular weight (Mw) of the acid-modified polypropylene wax exceeds the upper limit, the coverage of the treated fiber (described below) and the treated filler (described below) is decreased, resulting in a decrease in the strength of the resin composition (e.g., the treated fiber and treated filler described below).

[0072] The number average molecular weight (Mn) (polypropylene equivalent molecular weight) of the acid-modified polypropylene wax is, for example, 2000 or more, preferably 3500 or more, more preferably 4000 or more, and even more preferably 4500 or more. If the number average molecular weight (Mn) of the acid-modified polypropylene wax is above the above lower limit, embrittlement of the acid-modified polypropylene wax can be suppressed, and treated fibers (described below) and treated fillers (described below) with excellent strength can be obtained. Furthermore, the number average molecular weight (Mn) (polypropylene equivalent molecular weight) of the acid-modified polypropylene wax is, for example, 10000 or less, preferably 7000 or less, more preferably 6000 or less, and even more preferably 5000 or less. If the number average molecular weight (Mn) of the acid-modified polypropylene wax is below the above upper limit, the coverage of the treated fibers (described below) and treated fillers (described below) can be improved. As a result, treated fibers (described below) and treated fillers (described below) with excellent strength can be obtained.

[0073] The polydispersity (Mw / Mn) of the acid-modified polypropylene wax is, for example, 1.5 or more, preferably 2.0 or more, more preferably 2.5 or more, and even more preferably 3.0 or more. The polydispersity (Mw / Mn) of the acid-modified polypropylene wax is, for example, 20.0 or less, preferably 10.0 or less, more preferably 8.0 or less, and even more preferably 6.0 or less. When the polydispersity (Mw / Mn) of the acid-modified polypropylene wax is below the upper limit, the particle size distribution of the acid-modified polypropylene wax can be prevented from becoming excessively broad, and excellent storage stability can be obtained.

[0074] The density of the acid-modified polypropylene wax is, for example, 800 kg / cm 3 More than 820 kg / cm 3 More preferably, 850 kg / cm 3 The density of the acid-modified polypropylene wax is, for example, 980 kg / cm 3 Preferably, 950 kg / cm or less 3 or less, more preferably 920 kg / cm 3 The density is measured in accordance with the examples described below (the same applies hereinafter).

[0075] The softening point of the acid-modified polypropylene wax is, for example, 100°C or higher, preferably 130°C or higher, and more preferably 140°C or higher. If the softening point of the acid-modified polypropylene wax is higher than the lower limit, a resin composition (e.g., the treated fiber and treated filler described below) with excellent strength can be obtained. The softening point of the acid-modified polypropylene wax is, for example, 170°C or lower, preferably 150°C or lower, and more preferably 142°C or lower. The softening point is measured in accordance with the examples described below (the same applies hereinafter).

[0076] The 180°C melt viscosity of the acid-modified polypropylene wax is, for example, 300 mPa·s or more, preferably 500 mPa·s or more, and more preferably 800 mPa·s or more. If the 180°C melt viscosity of the acid-modified polypropylene wax is above the above-mentioned lower limit, the coverage of the treated fiber (described below) and the treated filler (described below) can be improved, and embrittlement of the acid-modified polypropylene wax can be suppressed, resulting in treated fiber (described below) and treated filler (described below) with excellent strength. Furthermore, the 180°C melt viscosity of the acid-modified polypropylene wax is, for example, 1000 mPa·s or less, preferably 950 mPa·s or less, and more preferably 920 mPa·s or less. If the 180°C melt viscosity of the acid-modified polypropylene wax is below the above-mentioned upper limit, excellent water dispersibility can be obtained. In other words, the particle size of the acid-modified polypropylene wax in water can be relatively small. Therefore, excellent storage stability can be obtained. The 180°C melt viscosity is measured in accordance with the examples described below (the same applies hereinafter).

[0077] From the viewpoint of low yellowness, the hue APHA of the acid-modified polypropylene wax is 500 or less, preferably 400 or less, and more preferably 300 or less. The hue APHA of the acid-modified polypropylene wax is usually 100 or more. The hue APHA is measured in accordance with the examples described later (the same applies hereinafter).

[0078] In addition, from the viewpoint of low yellowness, the ash content of the acid-modified polypropylene wax is, for example, 120 ppm or less, preferably 100 ppm or less, more preferably 80 ppm or less, even more preferably 50 ppm or less, even more preferably 30 ppm or less, even more preferably 20 ppm or less, and particularly preferably less than 10 ppm, relative to the total amount of the acid-modified polypropylene wax. The ash content of the acid-modified polypropylene wax is usually 0 ppm or more. The ash content of the acid-modified polypropylene wax is measured in accordance with the examples described below (the same applies hereinafter).

[0079] In addition, from the viewpoint of low yellowness, the calcium content of the acid-modified polypropylene wax is, for example, 15 ppm or less, preferably 10 ppm or less, more preferably 8 ppm or less, even more preferably 7 ppm or less, even more preferably 6 ppm or less, even more preferably 5 ppm or less, and particularly preferably 3 ppm or less, relative to the total amount of the acid-modified polypropylene wax. The calcium content of the acid-modified polypropylene wax is usually 0 ppm or more. The calcium content of the acid-modified polypropylene wax is measured in accordance with the examples described below (the same applies hereinafter).

[0080] In addition, from the viewpoint of low yellowness, the phosphorus content of the acid-modified polypropylene wax is, for example, 15 ppm or less, preferably 10 ppm or less, more preferably 8 ppm or less, even more preferably 5 ppm or less, even more preferably 3 ppm or less, even more preferably 2 ppm or less, and particularly preferably less than 1 ppm, relative to the total amount of the acid-modified polypropylene wax. The phosphorus content of the acid-modified polypropylene wax is usually 0 ppm or more. The phosphorus content of the acid-modified polypropylene wax is measured in accordance with the examples described below (the same applies hereinafter).

[0081] The acid-modified polypropylene wax may contain unreacted acids as inevitable impurities. The acid-modified polypropylene wax may contain by-products of the acid modification as inevitable impurities. Examples of by-products include acids, more specifically, oxalic acid, malonic acid, and succinic acid. Hereinafter, the unreacted acids and the by-product acids are collectively referred to as free acids.

[0082] The free acid content of the acid-modified polypropylene wax is, for example, 500 ppm or less, preferably 200 ppm or less, more preferably 180 ppm or less, based on the total amount of the acid-modified polypropylene wax. If the free acid content of the acid-modified polypropylene wax is below the upper limit, deterioration of color due to thermal degradation of the free acid can be suppressed in the production process of the resin composition (for example, the treated fiber and treated filler described below). The free acid content of the acid-modified polypropylene wax is usually 0 ppm or more. The free acid content of the acid-modified polypropylene wax is measured in accordance with the examples described below (the same applies hereinafter).

[0083] (4) Water dispersion The acid-modified polypropylene wax is dispersed in water to obtain an aqueous dispersion. The method for dispersing the acid-modified polypropylene wax in water is not particularly limited. For example, the acid-modified polypropylene wax and water are mixed and stirred by a known method.

[0084] The blending ratio of the acid-modified polypropylene wax per 100 parts by mass of water is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, and for example, 50 parts by mass or less, preferably 40 parts by mass or less.

[0085] The amount of the acid-modified polypropylene wax relative to the total amount of the acid-modified polypropylene wax and water is, for example, 10% by mass or more, preferably 20% by mass or more, and the amount of the acid-modified polypropylene wax relative to the total amount of the acid-modified polypropylene wax and water is, for example, 50% by mass or less, preferably 40% by mass or less.

[0086] For example, the amount of water is 50% by mass or more, preferably 60% by mass or more, based on the total amount of the acid-modified polypropylene wax and water, and 90% by mass or less, preferably 80% by mass or less, based on the total amount of the acid-modified polypropylene wax and water.

[0087] The method and conditions for mixing the acid-modified polypropylene wax with water are not particularly limited, and any known mixing method can be used to obtain an aqueous dispersion of the acid-modified polypropylene wax.

[0088] The aqueous dispersion may contain a neutralizing agent as needed. The neutralizing agent is not particularly limited as long as it can neutralize the carboxyl group of the acid-modified polypropylene wax, and any known neutralizing agent can be used. The blending ratio and blending timing of the neutralizing agent are appropriately determined depending on the purpose and application.

[0089] The aqueous dispersion may contain an emulsifier, if necessary. Examples of emulsifiers include nonionic emulsifiers and anionic emulsifiers. The blending ratio and blending timing of the emulsifier are appropriately determined depending on the purpose and application.

[0090] The aqueous dispersion may contain additives as needed. Examples of additives include silane coupling agents, sizing agents, antistatic agents, lubricants, smoothing agents, antifoaming agents, thickeners, tackifiers, hardness-imparting agents, preservatives, antifreezing agents, dispersants, pigments, and dyes. These additives may be used alone or in combination of two or more. The blending ratio and blending timing of the additives are appropriately determined depending on the purpose and application.

[0091] Such an aqueous dispersion has a relatively low yellowness. In particular, if the ash content, calcium content, and phosphorus content of the acid-modified polyolefin wax in the aqueous dispersion are relatively reduced, the aqueous dispersion has an even lower yellowness. Therefore, the aqueous dispersion is suitable for use as a surface treatment agent.

[0092] (5) Surface treatment agent The surface treatment agent contains the above-mentioned aqueous dispersion. The surface treatment agent may also contain additives as needed. Examples of additives include silane coupling agents, sizing agents, antistatic agents, lubricants, smoothing agents, antifoaming agents, thickeners, tackifiers, hardness-imparting agents, preservatives, antifreezing agents, dispersants, pigments, and dyes. These additives may be used alone or in combination of two or more. The blending ratio and blending timing of the additives are appropriately determined depending on the purpose and application.

[0093] The surface treatment agent contains the above-mentioned aqueous dispersion, and therefore has a relatively low yellowness. Therefore, the surface treatment agent is suitably used in the production of a resin composition containing a dried product of the surface treatment agent (the above-mentioned aqueous dispersion). Examples of such a resin composition include treated fibers and treated fillers.

[0094] (6) Treated fibers The treated fiber comprises a fiber and a dried product of the surface treatment agent. Examples of the fiber include inorganic and organic fibers. Examples of the inorganic fiber include glass fiber, carbon fiber, alumina fiber, ceramic fiber, rock fiber, and slag fiber. Examples of the organic fiber include olefin fiber, amide fiber, and pulp fiber. These fibers can be used alone or in combination of two or more types.

[0095] The dried product of the surface treatment agent is a resin layer containing an acid-modified polypropylene wax. The dried product coats at least a portion of the fiber. The coverage of the fiber with the dried product is not particularly limited and may be appropriately determined depending on the purpose and application.

[0096] The method for producing the treated fiber is not particularly limited, but involves applying a surface treatment agent to the surface of the fiber and heat treating it. Examples of application methods include dipping, spray coating, and roll coating. Heat treatment conditions are appropriately set depending on the surface treatment agent and the fiber. For example, the heat treatment temperature is 100 to 130°C. The heat treatment time is, for example, 1 to 12 hours.

[0097] Such treated fibers have a relatively low yellowness because they contain the dried product of the aqueous dispersion.

[0098] (7) Treated filler The treated filler comprises a filler and a dried product of the surface treatment agent. Examples of fillers include inorganic fillers and organic fillers. Examples of inorganic fillers include talc, alumina, silica, clay, barium sulfate, titanium oxide, kaolin, calcium oxide, glass balloons, bentonite, mica, sericite, magnesia, wollastonite, xonotlite, and whiskers. Examples of organic fillers include olefin particles, acrylic particles, polystyrene particles, melamine particles, and fluororesin particles. These fillers can be used alone or in combination.

[0099] The dried product of the surface treatment agent is a resin layer containing an acid-modified polypropylene wax. The dried product coats at least a portion of the filler. The coverage of the filler with the dried product is not particularly limited and may be appropriately set depending on the purpose and application.

[0100] The manufacturing method of the treated filler is not particularly limited, but includes applying a surface treatment agent to the surface of the filler and heat-treating the surface. Examples of application methods include immersion, spray coating, and roll coating. Heat-treatment conditions are appropriately set depending on the surface treatment agent and filler. For example, the heat-treatment temperature is 100 to 130°C. The heat-treatment time is, for example, 1 to 12 hours.

[0101] Such a treated filler has a relatively low yellowness because it contains the dried product of the above-mentioned aqueous dispersion. [Example]

[0102] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited thereto. Note that specific numerical values ​​of the blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(numerical values ​​defined as "equal to or less than") or lower limit values ​​(numerical values ​​defined as "equal to or more than" or "exceeding") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the above "Modes for Carrying Out the Invention."

[0103] <Raw materials> 1. High molecular weight polypropylene resin (raw polypropylene resin) J107G (Prime Polymer, polypropylene, MFR 30g / 10min) J208 (Prime Polymer, propylene-ethylene copolymer, MFR 40g / 10min)

[0104] 2. Low molecular weight polypropylene resin (unmodified polypropylene wax) LC 503NC (Propylene-ethylene copolymer, manufactured by Lion Chemtech) CS-53NC (Coschem, propylene-ethylene copolymer)

[0105] 3. Acid-modified polypropylene wax Production Example 1 (Production of Acid-Modified Polypropylene Wax (W1)) 200 g of commercially available polypropylene (product name J107G, manufactured by Prime Polymer Co., Ltd., polypropylene, MFR 30 g / 10 min) was placed in a 1.5 L stainless steel pyrolyzer equipped with a stirrer, nitrogen inlet tube, and condenser, and the system was thoroughly purged with nitrogen. Next, the pyrolyzer was heated to 380 °C while nitrogen was still flowing in to melt the resin, and then stirring was started. After the resin temperature in the system reached the specified temperature, the system was heated for 2.5 hours to carry out pyrolysis. The pyrolyzer was then cooled to room temperature, yielding the polypropylene wax (w1) shown in Table 1.

[0106] 500 g of polypropylene wax (w1) was placed in a glass reactor and melted at 170°C under a nitrogen atmosphere. 26 g of maleic anhydride and 5.5 g of di-t-butyl peroxide were then continuously added to the reactor over a period of 3 hours. The contents of the reactor were then heated and reacted for 1 hour. The contents of the reactor were degassed in a vacuum of 10 mmHg for 0.5 hours while still in the molten state to remove volatiles. The contents of the reactor were then cooled to obtain the acid-modified polypropylene wax (W1) shown in Table 2.

[0107] Production Example 2 (Production of Acid-Modified Polypropylene Wax (W2)) A polypropylene wax (w2) shown in Table 1 was obtained in the same manner as in Production Example 1, except that the polypropylene in Production Example 1 was changed to J208 (trade name, manufactured by Prime Polymer Co., Ltd., propylene-ethylene copolymer, MFR 40 g / 10 min).

[0108] Furthermore, the polypropylene wax (w2) was acid-modified in the same manner as in Production Example 1 to obtain the acid-modified polypropylene wax (W2) shown in Table 2.

[0109] Production Example 3 (Production of Acid-Modified Polypropylene Wax (W3)) A polypropylene wax (w3) shown in Table 1 was obtained in the same manner as in Production Example 2, except that the thermal decomposition temperature was 360°C and the thermal decomposition time was 3.5 hours.

[0110] Furthermore, the polypropylene wax (w3) was acid-modified in the same manner as in Production Example 1 to obtain the acid-modified polypropylene wax (W3) shown in Table 2.

[0111] Production Example 4 (Production of Acid-Modified Polypropylene Wax (W4)) An acid-modified polypropylene wax (W4) shown in Table 2 was obtained by acid-modifying LC 503NC (trade name, manufactured by Lion Chemtech, propylene-ethylene copolymer) in the same manner as in Production Example 1.

[0112] Production Example 5 (Production of Acid-Modified Polypropylene Wax (W5)) In the same manner as in Production Example 1, CS-53NC (trade name, manufactured by Coschem, propylene-ethylene copolymer) was acid-modified to obtain the acid-modified polypropylene wax (W5) shown in Table 2.

[0113] <Physical property measurement> The physical properties of the polypropylene wax and the acid-modified polypropylene wax were measured by the following methods, and the results are shown in Tables 1 and 2.

[0114] 1. 13 C-NMR measurement Regarding the polypropylene wax, the content ratio of the structural unit derived from ethylene and the content ratio of the structural unit derived from propylene are 13 It was determined by analyzing the C-NMR spectrum.

[0115] In addition, for the acid-modified polypropylene wax, the content ratio of the structural unit derived from ethylene, the content ratio of the structural unit derived from propylene, and the content ratio of the structural unit derived from an acid are calculated as follows: 13 It was determined by analyzing the C-NMR spectrum.

[0116] The measurement conditions are as follows. Apparatus: AVANCE IIIcryo-500 nuclear magnetic resonance spectrometer, manufactured by Bruker BioSpin Measurement frequency; 125MHz Solvent: orthodichlorobenzene / benzene-d6 (4 / 1 v / v) Sample concentration: 60mg / 0.6ml Measurement temperature: 120℃ Number of scans: 128 Repeat time: 5.5 seconds Pulse width: 45°

[0117] 2. GPC Measurement The weight average molecular weight, number average molecular weight, and dispersity of the polypropylene wax and the weight average molecular weight, number average molecular weight, and dispersity of the acid-modified polypropylene wax were measured by gel permeation chromatography (GPC) under the following conditions.

[0118] Apparatus: Gel permeation chromatograph Alliance GPC2000 (Waters) Mobile phase: o-dichlorobenzene Columns: TSKgel GMH6-HT x 2, TSKgel GMH6-HTL columns x 2 (both manufactured by Tosoh Corporation) Flow rate; 1.0 ml / min Sample: 0.15 mg / mL o-dichlorobenzene solution Temperature; 140℃ Detector; differential refractometer Calibration curve: Commercially available monodisperse standard polystyrene (PS)

[0119] The weight average molecular weight and number average molecular weight were determined as polypropylene equivalent values ​​(PP equivalent values) by a general calibration method.

[0120] 3. Density The densities of the polypropylene wax and the acid-modified polypropylene wax were measured in accordance with JIS K 7112 (1999).

[0121] 4.Softening point The softening points of the polypropylene wax and the acid-modified polypropylene wax were measured in accordance with JIS K 2207 (1996).

[0122] 5. Melt viscosity (180℃) The melt viscosity (180°C) of the polypropylene wax and the acid-modified polypropylene wax was measured in accordance with ASTM D2669.

[0123] 6. Hue APHA The color (APHA) of polypropylene wax and acid-modified polypropylene wax was measured in accordance with JIS K 0071-1 (2017).

[0124] 7.Ash content The total ash content of the polypropylene wax was measured in accordance with JIS K 7250-2 (2006).

[0125] 8. Residual calcium, residual phosphorus The residual calcium and phosphorus amounts in the polypropylene wax were measured by inductively coupled plasma mass spectrometry (ICP-MS) under the following measurement conditions.

[0126] Pretreatment: Polypropylene wax was heated and decomposed by adding sulfuric acid. Apparatus: ICP-MS / MS Agilent 8900 (Agilent Technologies)

[0127] 9. Acid value The acid value of the acid-modified polypropylene wax was measured in accordance with JIS K 5902 (2006).

[0128] 10. Free Acids (Residual Maleic Acid and Residual Succinic Acid) The amounts of residual maleic acid and succinic acid in the acid-modified polypropylene wax were measured by high performance liquid chromatography under the following conditions.

[0129] Device: LC4A type (Shimadzu Corporation) Mobile phase: acetonitrile (25%) / water (75%) Column: ZORBAX ODS (Agilent Technologies) Flow rate; 1ml / min Sample: 1 g of acid-modified polypropylene wax, 40 mL of xylene, and 20 mL of water were placed in a 500 mL Erlenmeyer flask and stirred at 95°C for 1 hour. The flask was then cooled to room temperature, and 200 mL of methanol was added to the flask. The insoluble components were then filtered through filter paper (No. 2). The filtrate was then concentrated using a rotary evaporator, and 20 mL of methanol was added to the resulting residue. This was used as the measurement sample. Temperature; 25℃ Detector: SPD-2A type (Shimadzu Corporation) Calibration curve: Aqueous solutions of maleic acid and succinic acid with known concentrations were prepared and a calibration curve was drawn.

[0130] <Aqueous dispersion of acid-modified polypropylene wax> Example 1 1150 g of water and 8.3 g of sodium hydroxide (0.55 equivalents relative to the maleic anhydride of the acid-modified polypropylene wax (W1)) were placed in a 4 L pressure-resistant homogenizer, heated to 180 ° C., and stirred at 5000 rpm. 450 g of molten acid-modified polypropylene wax (W1) was added over 1 hour using a gear pump. After stirring for another 1 hour, the mixture was cooled to room temperature to obtain the aqueous dispersion (EM-1, solids concentration = 30 mass%) shown in Table 3.

[0131] Example 2 An aqueous dispersion was prepared in the same manner as in Example 1, except that the acid-modified polypropylene wax (W1) in Example 1 was replaced with the acid-modified polypropylene wax (W2), to obtain the aqueous dispersion (EM-2, solid content = 30 mass%) shown in Table 3.

[0132] Example 3 An aqueous dispersion was prepared in the same manner as in Example 1, except that the acid-modified polypropylene wax (W1) in Example 1 was replaced with the acid-modified polypropylene wax (W3), to obtain the aqueous dispersion (EM-3, solid content = 30 mass%) shown in Table 3.

[0133] Comparative Example 1 An aqueous dispersion was prepared in the same manner as in Example 1, except that the acid-modified polypropylene wax (W1) in Example 1 was replaced with the acid-modified polypropylene wax (W4), to obtain the aqueous dispersion (EM-4, solid content = 30 mass%) shown in Table 3.

[0134] Comparative Example 2 An aqueous dispersion was prepared in the same manner as in Example 1, except that the acid-modified polypropylene wax (W1) in Example 1 was replaced with the acid-modified polypropylene wax (W5), to obtain the aqueous dispersion (EM-5, solid content = 30 mass%) shown in Table 3.

[0135] <Physical property measurement> The physical properties of the aqueous dispersion of the acid-modified polypropylene wax were measured by the following methods, and the results are shown in Table 3.

[0136] 1. Hue The b value of an aqueous dispersion of an acid-modified polypropylene wax was measured using a color difference system and the following evaluation points were obtained. 3 points: less than 0.15 2 points: 0.16 or more and less than 0.30 1 point: 0.31 or more

[0137] 2. Filterability A water dispersion (1 kg) of acid-modified polypropylene wax was placed on a metal mesh (10 μm mesh, 50 cm filtration area). 2 The time required for filtration was measured. The evaluation criteria are as follows. 3 points: Less than 1 minute 2 points: 1 minute to less than 1 minute 30 seconds 1 point: 1 minute 30 seconds or more

[0138] 3.Storage stability The aqueous dispersion of the acid-modified polypropylene wax was placed in a measuring cylinder (volume 200 mL), and the appearance was observed after 7 days. The evaluation criteria are as follows.

[0139] 3 points: The entire surface is uniform, or the acid-modified polypropylene wax particles have settled to form a transparent layer on top, and the proportion of the transparent layer to the total depth is less than 1%. 2 points: Acid-modified polypropylene wax particles have settled, forming a transparent layer on top, and the proportion of the transparent layer to the total depth is 1% or more but less than 5%. 1 point: Acid-modified polypropylene wax particles settle to form a transparent layer on top, and the proportion of the transparent layer to the total depth is 5% or more.

[0140] [Table 1]

[0141] [Table 2]

[0142] [Table 3]

Claims

1. The composition contains an acid-modified polypropylene wax obtained by modifying a polypropylene wax with an acid, and water in which the acid-modified polypropylene wax is dispersed, The acid comprises an unsaturated dicarboxylic acid, The acid-modified polypropylene wax contains structural units derived from propylene in a proportion of 80% by mass or more based on the total amount of the acid-modified polypropylene wax, The weight average molecular weight of the acid-modified polypropylene wax is 5,000 or more and 50,000 or less, The acid value of the acid-modified polypropylene wax is 1 mgKOH / g or more and 200 mgKOH / g or less, The color APHA of the acid-modified polypropylene wax is 500 or less, The aqueous dispersion of the acid-modified polypropylene wax has an ash content of 100 ppm or less.

2. The aqueous dispersion according to claim 1 , wherein the acid-modified polypropylene wax has a phosphorus content of 10 ppm or less.

3. The aqueous dispersion according to claim 1 or 2, wherein the acid-modified polypropylene wax has a calcium content of 10 ppm or less.

4. The aqueous dispersion according to any one of claims 1 to 3, wherein the acid-modified polypropylene wax has a free acid content of 200 ppm or less.

5. A surface treatment agent comprising the aqueous dispersion according to any one of claims 1 to 4.

6. A treated fiber comprising a fiber and the dried product of the surface treatment agent according to claim 5 that coats at least a portion of the fiber.

7. A treated filler comprising a filler and the dried product of the surface treatment agent according to claim 5 that coats at least a portion of the filler.

Images