Binder for pulverized toner, and pulverized toner

Abstract

To provide a binder for pulverized toner excellent in grindability, and a pulverized toner including the binder for pulverized toner.SOLUTION: A binder for pulverized toner includes a low molecular weight polymer and a high molecular weight polymer. The weight average molecular weight of the low molecular weight polymer is less than 25000. The weight average molecular weight of the high molecular weight polymer is equal to or more than 25000. The low molecular weight polymer is a polymer of a first monomer component. The high molecular weight polymer is a polymer of a second monomer component. At least any one of the first monomer component and the second monomer component includes a vinyl monomer having a cross-linking cyclic structure.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a binder for pulverized toner and pulverized toner.

Background Art

[0002] Conventionally, in copiers and laser printers, toner is used to print characters and the like.

[0003] Such toner is manufactured, for example, by a melt-kneading pulverization method. Specifically, in the melt-kneading pulverization method, after mixing a binder and a colorant, they are melt-kneaded to obtain a kneaded product, and then the kneaded product is pulverized to manufacture particulate toner.

[0004] As such a binder, for example, a binder resin for toner containing a low molecular weight vinyl resin (L) and a high molecular weight vinyl resin (H) has been proposed (see, for example, Example 1 of Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] On the other hand, when the particle size of the toner is reduced, the toner adhesion amount can be reduced during printing. Therefore, from the viewpoint of reducing the amount of toner used, reducing the particle size of the toner is considered.

[0007] However, in the melt-kneading pulverization method, when trying to reduce the particle size of the toner, there is a problem that higher energy is required and the pulverization speed becomes slower, resulting in a decrease in productivity when pulverizing the kneaded product.

[0008] Therefore, the binder is required to be crushable.

[0009] The present invention provides a binder for a crushable toner, and a crushable toner containing the binder for a crushable toner.

Means for Solving the Problems

[0010] The present invention [1] includes a low molecular weight polymer and a high molecular weight polymer, wherein the weight average molecular weight of the low molecular weight polymer is less than 25,000, the weight average molecular weight of the high molecular weight polymer is 25,000 or more, the low molecular weight polymer is a polymer of a first monomer component, the high molecular weight polymer is a polymer of a second monomer component, and at least one of the first monomer component and the second monomer component includes a vinyl monomer having a bridged cyclic structure, and is a binder for a crushable toner.

[0011] The present invention [2] includes the binder for a crushable toner according to the above [1], wherein both the first monomer component and the second monomer component include a vinyl monomer having a bridged cyclic structure.

[0012] The present invention [3] includes the binder for a crushable toner according to the above [2], wherein in the first monomer component, the content ratio of the vinyl monomer having a bridged cyclic structure is 5% by mass to 60% by mass, and in the second monomer component, the content ratio of the vinyl monomer having a bridged cyclic structure is 5% by mass to 60% by mass.

[0013] The present invention [4] includes the binder for a crushable toner according to any one of the above [1] to [3], wherein the vinyl monomer having a bridged cyclic structure is isobornyl (meth)acrylate.

[0014] The binder for pulverized toner according to any one of [1] to [3] above, wherein the first monomer component and / or the second monomer component contains a (meth)acrylate ester having an alkyl group with 8 to 22 carbon atoms.

[0015] The binder for pulverized toner according to any one of [1] to [5] above, wherein the first monomer component and / or the second monomer component contains an aromatic vinyl monomer.

[0016] The binder for pulverized toner according to any one of [1] to [6] above, wherein the first monomer component and / or the second monomer component contains a biomass-derived monomer.

[0017] The binder for pulverized toner according to [7] above, wherein the biomass content is 10% or more and 70% or less.

[0018] The pulverized toner contains the binder for pulverized toner according to any one of [1] to [8] above.

Advantages of the Invention

[0019] The binder for pulverized toner of the present invention contains a low molecular weight polymer that is a polymer of the first monomer component and a high molecular weight polymer that is a polymer of the second monomer component, and at least one of the first monomer component and the second monomer component contains a vinyl monomer having a bridged cyclic structure. Therefore, it has excellent pulverizability.

[0020] The pulverized toner of the present invention contains the binder for pulverized toner of the present invention. Therefore, it has excellent pulverizability.

Embodiments for Carrying Out the Invention

[0021] 1. Binder for Pulverized Toner The binder for pulverized toner contains a low molecular weight polymer and a high molecular weight polymer. If the binder for pulverized toner contains a low molecular weight polymer and a high molecular weight polymer, it has excellent fixability.

[0022] Also, although it will be described in detail later, the low molecular weight polymer is a polymer of a first monomer component, and the high molecular weight polymer is a polymer of a second monomer component. And at least one of the first monomer component and the second monomer component contains a vinyl monomer (described later) having a bridged cyclic structure. In other words, the first monomer component contains a vinyl monomer (described later) having a bridged cyclic structure, and the second monomer component does not contain a vinyl monomer (described later) having a bridged cyclic structure, or the first monomer component does not contain a vinyl monomer (described later) having a bridged cyclic structure, and the second monomer component contains a vinyl monomer (described later) having a bridged cyclic structure, or both the first monomer component and the second monomer component contain a vinyl monomer (described later) having a bridged cyclic structure.

[0023] In the following description, the case where both the first monomer component and the second monomer component contain a vinyl monomer (described later) having a bridged cyclic structure will be described in detail.

[0024] <Low molecular weight polymer> The low molecular weight polymer is a polymer having a relatively small weight average molecular weight compared to the high molecular weight polymer. Specifically, the weight average molecular weight (Mw) of the low molecular weight polymer is less than 25,000, preferably 20,000 or less, from the viewpoint of improving pulverizability, and is preferably 4,000 or more for the sake of achieving both low-temperature fixability and fixing strength of the toner.

[0025] The weight average molecular weight and the number average molecular weight are the weight average molecular weights in terms of polystyrene measured by gel permeation chromatography (GPC) (the same applies hereinafter).

[0026] The low molecular weight polymer is a polymer of the first monomer component.

[0027] [Vinyl monomer having a bridged cyclic structure] The first monomer component includes a vinyl monomer having a bridged cyclic structure. That is, the low molecular weight polymer includes structural units derived from a vinyl monomer having a bridged cyclic structure.

[0028] The bridged cyclic structure in the vinyl monomer having a bridged cyclic structure is not particularly limited as long as it exhibits steric hindrance described later, and examples thereof include a bridged alicyclic structure.

[0029] Examples of the functional group having a bridged alicyclic structure include a norbornyl group, an isobornyl group, a dicyclopentenyl group, a dicyclopentanyl group, a tricyclodecanyl group, and an adamantyl group. As the bridged alicyclic structure, a norbornyl group is preferably mentioned. That is, the vinyl monomer having a bridged cyclic structure is preferably a vinyl monomer having a norbornyl group.

[0030] From the viewpoint of grindability, the vinyl monomer having a norbornyl group is preferably isobornyl (meth)acrylate. More preferably, isobornyl methacrylate is mentioned as the vinyl monomer having a norbornyl group.

[0031] The vinyl monomer having a bridged cyclic structure can be used alone or in combination of two or more.

[0032] In the first monomer component, the content ratio of the vinyl monomer having a bridged cyclic structure is, for example, 5% by mass to 60% by mass, preferably 10% by mass to 58% by mass, more preferably 20% by mass to 57% by mass, still more preferably 30% by mass to 57% by mass, particularly preferably 40% by mass to 57% by mass, and most preferably 50% by mass to 57% by mass.

[0033] Specifically, in the first monomer component, the content ratio of the vinyl monomer having a bridged cyclic structure is, from the viewpoint of grindability, for example, 5% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, particularly preferably 40% by mass or more, most preferably 50% by mass or more. Also, from the viewpoint of the thermal properties required for the binder of the pulverized toner, for example, it is 60% by mass or less, preferably 58% by mass or less, more preferably 57% by mass or less.

[0034] [(meth)acrylic acid alkyl ester] The first monomer component preferably contains a (meth)acrylic acid alkyl ester. That is, the low molecular weight polymer contains a structural unit derived from a (meth)acrylic acid alkyl ester.

[0035] Examples of the (meth)acrylic acid alkyl ester include a (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms and a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms.

[0036] Examples of the (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-amyl (meth)acrylate, isoamyl (meth)acrylate, and n-hexyl (meth)acrylate. As the (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms, preferably, n-butyl (meth)acrylate is mentioned. As the (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms, more preferably, n-butyl acrylate is mentioned.

[0037] Examples of the (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms include octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, and octadecyl (meth)acrylate. As the (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms, lauryl (meth)acrylate is preferably mentioned. As the (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms, lauryl methacrylate is more preferably mentioned.

[0038] As the (meth)acrylic acid alkyl ester, it is preferable to use a combination of a (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms and a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms, or only a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms.

[0039] That is, preferably, the first monomer component contains a (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms and a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms, or contains a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms and does not contain a (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms. In other words, preferably, the first monomer component contains at least a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms.

[0040] When the first monomer component contains a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms, the glass transition temperature of the low molecular weight polymer can be adjusted to the range described later.

[0041] More preferably, the first monomer component contains a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms and does not contain a (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms.

[0042] (Meth)acrylic acid alkyl esters can be used alone or in combination of two or more kinds.

[0043] In the first monomer component, the content ratio of (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms is, for example, 5% by mass to 25% by mass, preferably 10% by mass to 20% by mass, more preferably 12% by mass to 15% by mass.

[0044] [Aromatic vinyl monomer] The first monomer component preferably contains an aromatic vinyl monomer. That is, the low molecular weight polymer contains a structural unit derived from an aromatic vinyl monomer.

[0045] Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, and chlorostyrene. Preferably, styrene is mentioned as the aromatic vinyl monomer.

[0046] Aromatic vinyl monomers can be used alone or in combination of two or more kinds.

[0047] [Vinyl monomer containing a carboxy group] The first monomer component preferably contains a vinyl monomer containing a carboxy group. That is, the low molecular weight polymer contains a structural unit derived from a vinyl monomer containing a carboxy group. When the first monomer component contains a vinyl monomer containing a carboxy group, the dispersibility of a colorant (described later) can be improved.

[0048] Examples of the vinyl monomer containing a carboxy group include monocarboxylic acids, dicarboxylic acids, or salts thereof. Examples of the monocarboxylic acid include (meth)acrylic acid. Examples of the dicarboxylic acid include itaconic acid, maleic acid, fumaric acid, itaconic anhydride, maleic anhydride, and fumaric anhydride.

[0049] As the carboxy group-containing vinyl monomer, preferably, monocarboxylic acid can be mentioned. As the carboxy group-containing vinyl monomer, more preferably, (meth)acrylic acid can be mentioned. As the carboxy group-containing vinyl monomer, even more preferably, methacrylic acid can be mentioned.

[0050] The carboxy group-containing vinyl monomer can be used alone or in combination of two or more.

[0051] In the first monomer component, the content ratio of the carboxy group-containing vinyl monomer is, for example, 0 mass% to 10 mass%, preferably, 0.5 mass% to 3 mass%.

[0052] [Other copolymerizable monomers] The first monomer component may optionally contain a vinyl monomer having a bridged cyclic structure, an alkyl (meth)acrylate, an aromatic vinyl monomer, and other copolymerizable monomers copolymerizable with the carboxy group-containing vinyl monomer (that is, the other copolymerizable monomers are copolymerizable monomers other than the vinyl monomer having a bridged cyclic structure, the alkyl (meth)acrylate, the aromatic vinyl monomer, and the carboxy group-containing vinyl monomer). That is, the low molecular weight polymer may optionally contain structural units derived from other copolymerizable monomers.

[0053] Examples of the other copolymerizable monomers include functional group-containing vinyl monomers (excluding carboxy group-containing vinyl monomers), vinyl esters, N-substituted unsaturated carboxylic acid amides, heterocyclic vinyl compounds, vinylidene halide compounds, α-olefins, dienes, and crosslinkable vinyl monomers.

[0054] Examples of the functional group-containing vinyl monomers include sulfonic acid group-containing vinyl monomers, phosphoric acid group-containing vinyl monomers, hydroxyl group-containing vinyl monomers, amino group-containing vinyl monomers, glycidyl group-containing vinyl monomers, cyano group-containing vinyl monomers, and acetoacetoxy group-containing vinyl monomers.

[0055] Examples of the vinyl monomer containing a sulfonic acid group include allyl sulfonic acid, methallyl sulfonic acid, and acrylamide t-butyl sulfonic acid. The vinyl monomer containing a sulfonic acid group includes its salts. Examples of the salt of the vinyl monomer containing a sulfonic acid group include alkali metal salts (e.g., sodium salt, potassium salt), and ammonium salts. Specifically, for example, sodium allyl sulfonate, sodium methallyl sulfonate, and ammonium methallyl sulfonate can be mentioned.

[0056] Examples of the vinyl monomer containing a phosphate group include 2-methacryloyloxyethyl acid phosphate.

[0057] Examples of the vinyl monomer containing a hydroxyl group include 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate.

[0058] Examples of the vinyl monomer containing an amino group include 2-aminoethyl (meth)acrylate, 2-(N-methylamino)ethyl (meth)acrylate, and 2-(N,N-dimethylamino)ethyl (meth)acrylate.

[0059] Examples of the vinyl monomer containing a glycidyl group include glycidyl (meth)acrylate.

[0060] Examples of the vinyl monomer containing a cyano group include (meth)acrylonitrile.

[0061] Examples of the vinyl monomer containing an acetoacetoxy group include acetoacetoxyethyl (meth)acrylate.

[0062] Examples of the vinyl esters include vinyl acetate, and vinyl propionate.

[0063] Examples of the N-substituted unsaturated carboxylic acid amide include N-methylol (meth)acrylamide.

[0064] Examples of the heterocyclic vinyl compound include vinyl pyrrolidone.

[0065] Examples of the vinylidene halide compound include vinylidene chloride and vinylidene fluoride.

[0066] Examples of the α-olefins include ethylene and propylene.

[0067] Examples of the dienes include butadiene.

[0068] Examples of the crosslinkable vinyl monomer include vinyl monomers containing two or more vinyl groups. Examples of the vinyl monomers containing two or more vinyl groups include methylene bis(meth)acrylamide, divinylbenzene, di(meth)acrylate containing a polyethylene glycol chain, trimethylolpropane tetraacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate.

[0069] Other copolymerizable monomers can be used alone or in combination of two or more.

[0070] In the first monomer component, the content ratio of other copolymerizable monomers is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 1% by mass or less, and still more preferably 0% by mass. That is, still more preferably, the first monomer component does not contain other copolymerizable monomers and consists of a vinyl monomer having a bridged cyclic structure, an alkyl (meth)acrylate, an aromatic vinyl monomer, and a vinyl monomer containing a carboxy group.

[0071] In addition, from the perspective of reducing environmental impact, the vinyl monomer having the above-mentioned bridged cyclic structure, (meth)acrylic acid alkyl ester (the (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms and the (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms), aromatic vinyl monomer, carboxy group-containing vinyl monomer, and other copolymerizable monomers are preferably biomass-derived monomers. That is, the first monomer component preferably contains biomass-derived monomers. In other words, the low molecular weight polymer preferably contains structural units derived from biomass-derived monomers.

[0072] More preferably, the vinyl monomer having a bridged cyclic structure and the (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms are biomass-derived monomers.

[0073] The biomass-derived monomer is a monomer having biomass-derived carbon measured by the method described in ASTM (American Standard Test Methods) D6866 and estimated from the carbon isotope content of mass number 14, and the content of biomass-derived carbon (biomass degree) in the total carbon of the biomass-derived monomer is, for example, 60% or more, preferably 70% or more.

[0074] [Preparation of Low Molecular Weight Polymer] The low molecular weight polymer is prepared by polymerizing the first monomer component.

[0075] The polymerization method is not particularly limited, and suspension polymerization, emulsion polymerization, bulk polymerization, solution polymerization, etc. can be used. Preferably, solution polymerization is selected.

[0076] When solution polymerization is employed as the polymerization method, the first monomer component is blended with a solvent in an appropriate ratio and polymerized.

[0077] Examples of the solvent include aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene, and cumene. Preferably, xylene is mentioned as the solvent.

[0078] The solvent(s) can be used alone or in combination of two or more kinds.

[0079] The polymerization may be carried out using a polymerization initiator or may be so-called thermal polymerization without using a polymerization initiator.

[0080] As the polymerization initiator, those that can usually be used as radical polymerization initiators can be used. Examples of the polymerization initiator include azo initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl-2,2'-azobisisobutyrate, 1,1'-azobis(1-cyclohexanecarbonitrile), 2-(carbamoylazo)-isobutyronitrile, 2,2'-azobis(2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2,2'-azobis(2-methyl-propane); ketone peroxides such as methyl ethyl ketone peroxide, acetylacetone peroxide, cyclohexanone peroxide; peroxyketals such as 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(butylperoxy)cyclohexane, 2,2-bis(t-butylperoxy)butane; hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide; dialkyl peroxides such as di-t-butyl peroxide, t-butyl cumyl peroxide, di-cumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, α,α'-bis(t-butylperoxyisopropyl)benzene; and peroxides such as isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,Diacyl peroxides such as 5-trimethylhexanoyl peroxide, benzoyl peroxide, m-toluoyl peroxide, peroxydicarbonates such as di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, di-methoxyisopropyl peroxydicarbonate, di(3-methyl-3-methoxybutyl) peroxydicarbonate, sulfonyl peroxides such as acetylcyclohexylsulfonyl peroxide, peroxy esters such as t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, cumyl peroxyneodecanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl diperoxyisophthalate, etc. can be mentioned.,

[0081] The polymerization temperature and the polymerization time are appropriately selected according to the type and amount of the polymerization initiator and the type and amount of the solvent.,

[0082] Thereby, a low molecular weight polymer (reaction solution of the low molecular weight polymer) is prepared.,

[0083] The glass transition temperature described above will be described in detail in the examples described later, but it can be measured by differential scanning calorimetry (DSC) (the same applies hereinafter).

[0084] The method for measuring the softening point will be described in detail in the examples described later (the same applies hereinafter).

[0085] The acid value of the low molecular weight polymer is, for example, 0 mgKOH / g to 30 mgKOH / g, preferably 0 mgKOH / g to 10 mgKOH / g.,

[0086] The method for measuring the acid value will be described in detail in the examples described later (the same applies hereinafter).

[0087] The biomass content of the low molecular weight polymer is, for example, 10% or more.

[0088] The low molecular weight polymer can be used alone or in combination of two or more.

[0089] <High molecular weight polymer> The high molecular weight polymer is a polymer having a relatively large weight average molecular weight compared to the low molecular weight polymer. Specifically, the weight average molecular weight of the high molecular weight polymer is 25,000 or more, preferably 50,000 or more, and, from the viewpoint of improving pulverizability, for example, 700,000 or less. When the weight average molecular weight (Mw) of the high molecular weight polymer is within the above range, as the fixing property of the toner, high temperature offset does not occur and the low temperature fixing property is also good.

[0090] The high molecular weight polymer is a polymer of the second monomer component.

[0091] [Vinyl monomer having a bridged cyclic structure] The second monomer component includes a vinyl monomer having the above bridged cyclic structure. That is, the high molecular weight polymer includes a structural unit derived from a vinyl monomer having a bridged cyclic structure.

[0092] Examples of the vinyl monomer having a bridged cyclic structure preferably include vinyl monomers having a norbornyl group. More preferably, isobornyl (meth)acrylate is mentioned as the vinyl monomer having a bridged cyclic structure. Even more preferably, isobornyl methacrylate is mentioned as the vinyl monomer having a bridged cyclic structure.

[0093] The vinyl monomer having a bridged cyclic structure can be used alone or in combination of two or more.

[0094] In the second monomer component, the content ratio of the vinyl monomer having a bridged cyclic structure is, for example, 5% by mass to 60% by mass, preferably 10% by mass to 58% by mass, more preferably 20% by mass to 57% by mass, still more preferably 30% by mass to 57% by mass, particularly preferably 40% by mass to 57% by mass, and most preferably 50% by mass to 57% by mass. Preferably, the content ratio of the vinyl monomer having a bridged cyclic structure in the second monomer component is the same as the content ratio of the vinyl monomer having a bridged cyclic structure in the first monomer component.

[0095] Specifically, in the second monomer component, the content ratio of the vinyl monomer having a bridged cyclic structure is, from the viewpoint of grindability, for example, 5% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, particularly preferably 40% by mass or more, and most preferably 50% by mass or more. Also, from the viewpoint of the thermal properties required for the binder for the pulverized toner, it is, for example, 60% by mass or less, preferably 58% by mass or less, and more preferably 57% by mass or less.

[0096] [(Meth)acrylic acid alkyl ester] The second monomer component preferably contains the above (meth)acrylic acid alkyl ester. That is, the high molecular weight polymer contains a structural unit derived from the (meth)acrylic acid alkyl ester.

[0097] Examples of the (meth)acrylic acid alkyl ester include the (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms and the (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms described above.

[0098] Examples of the (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms preferably include n-butyl (meth)acrylate. More preferably, examples of the (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms include n-butyl acrylate.

[0099] As the (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms, preferably, lauryl (meth)acrylate can be mentioned. As the (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms, more preferably, lauryl methacrylate can be mentioned.

[0100] The second monomer component preferably contains a (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms and a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms, or contains a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms and does not contain a (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms. In other words, preferably, the second monomer component contains at least a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms.

[0101] When the second monomer component contains a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms, the glass transition temperature of the high molecular weight polymer can be adjusted to the range described later.

[0102] More preferably, the second monomer component contains a (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms and does not contain a (meth)acrylic acid ester having an alkyl group with 1 to 7 carbon atoms.

[0103] (Meth)acrylic acid alkyl esters can be used alone or in combination of two or more.

[0104] In the second monomer component, the content ratio of the (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms is, for example, 1% by mass to 40% by mass, preferably, 5% by mass to 35% by mass, more preferably, 10% by mass to 33% by mass, still more preferably, 25% by mass to 32% by mass.

[0105] [Aromatic vinyl monomer] The second monomer component preferably includes the above aromatic vinyl monomer. That is, the high molecular weight polymer includes structural units derived from the aromatic vinyl monomer.

[0106] Preferably, styrene is mentioned as the aromatic vinyl monomer.

[0107] The aromatic vinyl monomer can be used alone or in combination of two or more.

[0108] [Vinyl monomer containing carboxyl group] The second monomer component preferably includes the above vinyl monomer containing a carboxyl group. That is, the high molecular weight polymer includes structural units derived from the vinyl monomer containing a carboxyl group. When the second monomer component includes a vinyl monomer containing a carboxyl group, the dispersibility of a colorant (described later) can be improved.

[0109] Preferably, monocarboxylic acid is mentioned as the vinyl monomer containing a carboxyl group. More preferably, (meth)acrylic acid is mentioned as the vinyl monomer containing a carboxyl group. Even more preferably, methacrylic acid is mentioned as the vinyl monomer containing a carboxyl group.

[0110] The vinyl monomer containing a carboxyl group can be used alone or in combination of two or more.

[0111] In the second monomer component, the content ratio of the vinyl monomer containing a carboxyl group is, for example, 0 mass% to 10 mass%, preferably 1 mass% to 5 mass%, more preferably 2 mass% to 4 mass%.

[0112] [Other copolymerizable monomers] The second monomer component may optionally include the above other copolymerizable monomers. That is, the high molecular weight polymer may optionally include structural units derived from other copolymerizable monomers.

[0113] The other copolymerizable monomers can be used alone or in combination of two or more.

[0114] In the second monomer component, the content ratio of other copolymerizable monomers is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 1% by mass or less, and still more preferably 0% by mass. That is, still more preferably, the second monomer component does not contain other copolymerizable monomers and consists of a vinyl monomer having a bridged cyclic structure, an alkyl (meth)acrylate, an aromatic vinyl monomer, and a vinyl monomer containing a carboxy group.

[0115] Also, similar to the first monomer component, the vinyl monomer having the above-described bridged cyclic structure, the alkyl (meth)acrylate (the (meth)acrylate having an alkyl group having 1 to 7 carbon atoms and the (meth)acrylate having an alkyl group having 8 to 22 carbon atoms), the aromatic vinyl monomer, the vinyl monomer containing a carboxy group, and other copolymerizable monomers are preferably biomass-derived monomers from the viewpoint of reducing environmental load. That is, the second monomer component preferably contains biomass-derived monomers. In other words, the low molecular weight polymer preferably contains a structural unit derived from a biomass-derived monomer.

[0116] More preferably, the vinyl monomer having a bridged cyclic structure and the (meth)acrylate having an alkyl group having 8 to 22 carbon atoms are biomass-derived monomers.

[0117] Also, each component in the first monomer component (the vinyl monomer having a bridged cyclic structure, the alkyl (meth)acrylate, the aromatic vinyl monomer, the vinyl monomer containing a carboxy group, and other copolymerizable monomers) and each component in the second monomer component are preferably selected from the same type.

[0118] In particular, from the perspective of compatibility, preferably, in both the first monomer component and the second monomer component, the vinyl monomer having a bridged cyclic structure contains isobornyl methacrylate, and more preferably, the vinyl monomer having a bridged cyclic structure consists of isobornyl methacrylate.

[0119] Also, when the vinyl monomer having a bridged cyclic structure contains isobornyl methacrylate in both the first monomer component and the second monomer component, the content ratio of isobornyl methacrylate is preferably 5% by mass or more and 60% by mass or less with respect to the first monomer component, and also preferably 5% by mass or more and 60% by mass or less with respect to the second monomer component.

[0120] Also, from the perspective of suppressing phase separation and improving the performance of the pulverized toner (for example, fixability), preferably, the content ratio of isobornyl methacrylate with respect to the first monomer component and the content ratio of isobornyl methacrylate with respect to the second monomer component are adjusted to be approximately the same. Specifically, the ratio of the content ratio of isobornyl methacrylate with respect to the first monomer component to the content ratio of isobornyl methacrylate with respect to the second monomer component is, for example, 0.3 to 3.0, preferably 0.5 to 2.0, more preferably 0.7 to 1.8, and even more preferably 0.9 to 1.1.

[0121] When each component in the first monomer component and each component in the second monomer component are of the same type, for example, by adjusting the content ratio and / or polymerization conditions of each component, the weight average molecular weight of the low molecular weight polymer and the weight average molecular weight of the high molecular weight polymer are adjusted to the above ranges. Preferably, by adjusting the polymerization conditions, the weight average molecular weight of the low molecular weight polymer and the weight average molecular weight of the high molecular weight polymer are adjusted to the above ranges.

[0122] [Preparation of High Molecular Weight Polymer] The high molecular weight polymer is prepared by polymerizing the second monomer component.

[0123] The polymerization method is not particularly limited, and examples thereof include suspension polymerization, emulsion polymerization, bulk polymerization, solution polymerization, and combinations thereof. As the polymerization method, bulk polymerization and solution polymerization are preferred. Specifically, first, in a nitrogen atmosphere, the second monomer component is polymerized (bulk polymerization), and then a solvent (for example, the solvents mentioned in the low molecular weight polymer, preferably xylene) and, if necessary, a polymerization initiator (for example, the polymerization initiators mentioned in the low molecular weight polymer, preferably di-t-butyl peroxide) are blended at appropriate ratios and polymerized (solution polymerization).

[0124] The polymerization temperature and polymerization time are appropriately selected according to the type and amount of the polymerization initiator and the type and amount of the solvent.

[0125] Thereby, a high molecular weight polymer (reaction solution of the high molecular weight polymer) is prepared.

[0126] The acid value of the high molecular weight polymer is, for example, 0 mgKOH / g to 35 mgKOH / g, preferably 0 mgKOH / g to 30 mgKOH / g.

[0127] The biomass degree of the high molecular weight polymer is, for example, 10% or more.

[0128] The high molecular weight polymer can be used alone or in combination of two or more.

[0129] In addition, a crosslinking agent (specifically, a glycidyl group-containing vinyl polymer) described in International Publication No. 2004 / 015498 and / or a glycidyl group-containing vinyl resin described in International Publication No. 2013 / 176016 may be added to a binder composed of a high molecular weight polymer and a low molecular weight polymer to cause a crosslinking reaction.

[0130] <Additive> The binder for pulverized toner may contain an additive if necessary.

[0131] Examples of the additive include a release agent, a plasticizer, and an ultraviolet absorber.

[0132] Examples of the release agent include polypropylene wax, polyethylene wax, paraffin wax, rice wax, ester wax, and Fischer-Tropsch wax.

[0133] The blending ratio of the additive is appropriately set according to the use and purpose.

[0134] The additive can be used alone or in combination of two or more.

[0135] <Manufacture of Binder for Pulverized Toner> The binder for pulverized toner is obtained by mixing a low molecular weight polymer, a high molecular weight polymer, and an additive blended as needed.

[0136] The mass ratio of the high molecular weight polymer to the low molecular weight polymer (high molecular weight polymer / low molecular weight polymer) is, for example, 30 / 70 to 60 / 40. Preferably, the smaller the mass ratio of the high molecular weight polymer to the low molecular weight polymer (the more the low molecular weight polymer relative to the high molecular weight polymer), the more the pulverizability can be improved.

[0137] Also, the content ratio of the vinyl monomer having a bridged cyclic structure is 5% by mass to 60% by mass, preferably 10% by mass to 58% by mass, more preferably 20% by mass to 57% by mass, still more preferably 30% by mass to 57% by mass, particularly preferably 40% by mass to 57% by mass, and most preferably 50% by mass to 57% by mass with respect to the total amount of the first monomer component and the second monomer component.

[0138] Specifically, from the perspective of grindability, the content ratio of the vinyl monomer having a bridged cyclic structure is, for example, 5% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, particularly preferably 40% by mass or more, and most preferably 50% by mass or more, based on the total amount of the first monomer component and the second monomer component. From the perspective of compatibility, for example, it is 60% by mass or less, preferably 58% by mass or less, more preferably 57% by mass or less.

[0139] In addition, the content ratio of the (meth)acrylic acid ester having an alkyl group with 8 to 22 carbon atoms is, for example, 5% by mass to 25% by mass, preferably 10% by mass to 23% by mass, more preferably 15% by mass to 21% by mass, based on the total amount of the first monomer component and the second monomer component.

[0140] Also, the content ratio of the carboxy group-containing vinyl monomer is, for example, 0% by mass to 10% by mass, preferably 1.0% by mass to 5% by mass, more preferably 1.5% by mass to 3% by mass, based on the total amount of the first monomer component and the second monomer component.

[0141] The content ratio of other copolymerizable monomers is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 1% by mass or less, still more preferably 0% by mass, based on the total amount of the first monomer component and the second monomer component.

[0142] In addition, in the above mixing, the solvent can also be removed by known methods such as distillation and extraction.

[0143] Thereby, a binder for pulverized toner containing a low molecular weight polymer, a high molecular weight polymer, and, if necessary, an additive is produced.

[0144] The weight average molecular weight (Mw) of the binder for pulverized toner is, for example, 30,000 to 35,000, preferably 100,000 to 300,000, more preferably 150,000 to 250,000, still more preferably 200,000 to 240,000.

[0145] The glass transition temperature (Tg) of the binder for pulverized toner is, for example, 40°C to 70°C, preferably 40°C to 60°C.

[0146] The softening point (Tm) of the binder for pulverized toner is, for example, 110°C to 150°C.

[0147] The acid value of the binder for pulverized toner is, for example, 0 mgKOH / g to 30 mgKOH / g, preferably 10 mgKOH / g to 20 mgKOH / g.

[0148] The biomass content of the binder for pulverized toner is, for example, 10% or more, preferably 20% or more, more preferably 30% or more, still more preferably 40% or more, particularly preferably 50% or more, and, for example, 70% or less, preferably 60% or less.

[0149] Since the binder for pulverized toner contains vinyl monomers having a bridging cyclic structure in both the first monomer component and the second monomer component, it has excellent pulverizability. Therefore, such a binder for pulverized toner is suitably used in the production of pulverized toner. Hereinafter, the pulverized toner obtained using this binder for pulverized toner will be described in detail.

[0150] 2. Pulverized Toner The pulverized toner contains a binder for pulverized toner, a colorant, and, if necessary, an additive.

[0151] Examples of the colorant include known pigments and dyes.

[0152] Examples of the additive include a charge control agent, a release agent, and a pigment dispersant.

[0153] Then, the pulverized toner is manufactured by the melt-kneading pulverization method. Specifically, after premixing a binder for the pulverized toner, a colorant, a charge control agent optionally blended, and a release agent optionally blended, they are kneaded in a heated and molten state using a twin-screw kneader. After cooling this, it is pulverized using a fine pulverizer, further classified by an air classifier to collect particles in the range of 2 to 10 μm, and mixed with an external additive such as silica to adhere the external additive to the particle surface.

[0154] Thereby, particulate pulverized toner is manufactured.

[0155] The average particle diameter of the pulverized toner is, for example, 1 μm to 10 μm.

[0156] 3. Effects The binder for the pulverized toner contains a low molecular weight polymer that is a polymer of the first monomer component and a high molecular weight polymer that is a polymer of the second monomer component, and the first monomer component and the second monomer component contain a vinyl monomer having a bridging cyclic structure. Therefore, it is excellent in pulverizability.

[0157] Specifically, when the particle diameter of the toner is reduced, the toner adhesion amount can be reduced during printing. Therefore, from the viewpoint of reducing the usage amount of the pulverized toner, reducing the particle diameter of the pulverized toner is considered.

[0158] However, in the melt-kneading pulverization method, when trying to reduce the particle diameter of the pulverized toner, higher energy is required when pulverizing the kneaded product, the pulverization speed becomes slower, and the productivity decreases.

[0159] On the other hand, in this binder for the pulverized toner, since the first monomer component and the second monomer component contain a vinyl monomer having a bridging cyclic structure, aggregation of the low molecular weight polymer and the high molecular weight polymer can be suppressed by steric hindrance derived from the bridging cyclic structure.

[0160] By suppressing the above aggregation, the energy required for pulverization can be reduced (i.e., the pulverizability is improved). As a result, even if the particle size of the pulverized toner is reduced, a decrease in productivity can be suppressed.

[0161] The pulverized toner contains a binder for pulverized toner. Therefore, it has excellent pulverizability.

[0162] 4. Modification Example In the above description, both the first monomer component and the second monomer component contain a vinyl monomer having a bridged cyclic structure, but either the first monomer component or the second monomer component may contain a vinyl monomer having a bridged cyclic structure.

[0163] From the viewpoint of the compatibility between the high molecular weight polymer and the low molecular weight polymer, preferably, both the first monomer component and the second monomer component contain a vinyl monomer having a bridged cyclic structure.

[0164] In the above description, both the first monomer component and the second monomer component contain a (meth)acrylate having an alkyl group with 8 to 22 carbon atoms, but either the first monomer component or the second monomer component may contain a (meth)acrylate having an alkyl group with 8 to 22 carbon atoms.

[0165] From the viewpoint of adjusting the glass transition temperature, preferably, both the first monomer component and the second monomer component contain a (meth)acrylate having an alkyl group with 8 to 22 carbon atoms.

[0166] In the above description, both the first monomer component and the second monomer component contain an aromatic vinyl monomer, but either the first monomer component or the second monomer component may contain an aromatic vinyl monomer.

[0167] From the viewpoint of the compatibility between the high molecular weight polymer and the low molecular weight polymer, preferably, both the first monomer component and the second monomer component contain an aromatic vinyl monomer.

[0168] In the above description, both the first monomer component and the second monomer component preferably contain monomers derived from biomass, but either the first monomer component or the second monomer component may contain monomers derived from biomass.

[0169] From the viewpoint of reducing the environmental load, preferably, both the first monomer component and the second monomer component contain monomers derived from biomass.

Examples

[0170] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited by the following examples. In addition, "parts" and "%" are based on mass unless otherwise specified. Also, specific numerical values such as the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values (numerical values defined as "hereinafter", "less than") or lower limit values (numerical values defined as "above", "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Mode for Carrying Out the Invention".

[0171] <Details of Components> The trade names and abbreviations of the components used in each example and each comparative example will be described in detail. St: Styrene n-BA: n-Butyl acrylate IBX: Isobornyl methacrylate (biomass content 71%) LMA: Lauryl methacrylate (biomass content 75%) Mac: Methacrylic acid

[0172] <Production of Low Molecular Weight Polymer> Production Example 1 75 parts by mass of xylene was charged into a nitrogen-substituted flask and the temperature was raised. Next, a mixed solution of the first monomer component described in Table 1 and 1.8 parts by mass of t-butyl peroxy-2-ethylhexanoate was continuously added dropwise over 5 hours under reflux of xylene, and further refluxed for 1 hour. Thereafter, the internal temperature was maintained at 98 °C, and further, 0.5 part by weight of t-butyl peroxy-2-ethylhexanoate was added and reacted for 1 hour, and further 0.5 part by weight of t-butyl peroxy-2-ethylhexanoate was added and reacted for 2 hours. Thereby, a reaction solution of a low molecular weight polymer was produced. The numerical values of each component in Table 1 are in mass %.

[0173] Production Examples 2 to 6 Based on the same procedure as in Production Example 1, a reaction solution of a low molecular weight polymer was produced. However, the formulation of the first monomer component was changed based on Table 1, and 1.8 parts by mass of t-butyl peroxy-2-ethylhexanoate was changed to 3 parts by mass of 1.8 parts by mass of t-butyl peroxy-2-ethylhexanoate.

[0174] <Production of High Molecular Weight Polymer> Production Examples 7 to 10 The second monomer component described in Table 1 was blended into a nitrogen-substituted flask, the internal temperature was raised to 120 °C, and bulk polymerization was carried out while maintaining the temperature. Next, 30 parts by weight of xylene was charged when the Gardner viscosity at 25 °C reached Z. Thereafter, after 30 minutes elapsed, the temperature was raised to 130 °C and maintained. Next, a mixed solution (a mixed solution of 50 parts by mass of xylene and 0.1 part by mass of di-t-butyl peroxide) was continuously added dropwise over 4 hours, and further maintained at 130 °C for 1 hour. Thereafter, 20 parts by mass of xylene was added for dilution.

[0175] Next, the internal temperature was maintained at 130 °C, and further, 0.2 part by mass of di-t-butyl peroxide was added and the reaction was continued for 2 hours. Next, further, 0.2 part by mass of di-t-butyl peroxide was added and the reaction was continued for 2 hours. Thereby, a reaction solution of a high molecular weight polymer was produced.

[0176] <Production of Binder for Pulverized Toner> Examples 1 to 5 and Comparative Example 1 Based on the description in Table 2, a low molecular weight polymer and a high molecular weight polymer were mixed. Then, the solvent (xylene) was removed by distillation (190 °C, 1.33 kPa). Thereby, a binder for pulverized toner was produced.

[0177] <Evaluation> [Weight-average molecular weight and number-average molecular weight] For the low molecular weight polymer of each production example, the high molecular weight polymer of each production example, and the binder for pulverized toner of each example, the weight-average molecular weight in terms of polystyrene was measured by gel permeation chromatography (GPC). The results are shown in Table 1 and Table 2. The measurement conditions are as follows. [Measurement conditions] GPC apparatus: Prominence 501 system (manufactured by Shoko Science Co., Ltd.) Detector: SHODEX RI-501 (manufactured by Resonac Holdings Corporation) Column: One SHODEX GPC KF-G, three SHODEX GPC KF-807L, and one SHODEX GPC KF-800D (manufactured by Resonac Holdings Corporation) were connected in series in this order and used. Solvent: Tetrahydrofuran (THF) Flow rate: 1.2 ml / min Sample concentration: 0.002 g-resin / ml-THF Injection volume: 100 μL

[0178] [Glass transition temperature] For the low molecular weight polymer of each production example, the high molecular weight polymer of each production example, and the binder for pulverized toner of each example, the glass transition temperature was measured. Specifically, using a differential scanning calorimeter (DSC-7000X, Hitachi High-Tech Science), 10 mg of the sample was placed in an aluminum pan, melted at 200 °C, then cooled to 0 °C to solidify, and the glass transition temperature was determined from the heat quantity change when the temperature was raised at 10 °C / min. The results are shown in Table 1 and Table 2.

[0179] [Softening point] The softening points of the low-molecular-weight polymers of each production example, the high-molecular-weight polymers of each production example, and the binders for pulverized toners of each example were measured. Specifically, using a flow tester (CFT, Shimadzu Corporation), a die with a 1-mm diameter and a 1-mm depth hole was installed at the bottom of the furnace, the furnace was set at 80 °C, 1 g of the sample was placed in the furnace, a piston was inserted from above, a 20-kg load was applied to the piston, and the displacement of the piston and the temperature were measured while the temperature was increased at a rate of 6 °C / min. The results are shown in Tables 1 and 2.

[0180] [Acid value] The acid values of the low-molecular-weight polymers of each production example, the high-molecular-weight polymers of each production example, and the binders for pulverized toners of each example were measured. Specifically, the accurately weighed sample was dissolved in a mixed solvent of xylene:n-butanol = 1:1 by mass ratio. Titration was performed with an alcohol of N / 10 potassium hydroxide (prepared by adding 5 g of ion-exchanged water to 7 g of special-grade potassium hydroxide, making it 1 L (liter) with primary ethyl alcohol, and calibrating the titer = F with N / 10 hydrochloric acid and 1% phenolphthalein solution), and it was calculated according to the following formula from the neutralization amount. The results are shown in Tables 1 and 2. Acid value (mgKOH / g) = (N / 10 KOH titration volume (ml) × F × 5.61) / (sample g × 0.01)

[0181] [Biomass content] The biomass contents of the low-molecular-weight polymers of each production example, the high-molecular-weight polymers of each production example, and the binders for pulverized toners of each example were calculated by the method described in ASTM (American Standard Test Methods) D6866. The results are shown in Tables 1 and 2.

[0182] [Pulverizability (pulverization rate)] The binders for pulverized toners of each example were roughly pulverized through a power mill (manufactured by Dalton) equipped with a 2-mm mesh screen.

[0183] Next, the binder for the coarsely pulverized toner was quantitatively fed into an air jet mill (SJ-100CB-C, manufactured by Nisshin Engineering Co., Ltd.) with an air pressure of 0.7 MPa, and the discharged finely pulverized material was measured with a particle size distribution measuring device (Multisizer3, manufactured by Beckman Coulter, Inc.) to measure the particle size of the finely pulverized material. The feed rate was adjusted so that the median diameter in the volume distribution of the finely pulverized material was 7.0 to 7.9 μm. Under those conditions, the pulverization rate was calculated from the recovery amount of the finely pulverized material with a median diameter of 7.0 to 7.9 μm and the pulverization time. The results are shown in Table 2.

[0184] <Discussion> It can be seen that Examples 1 to 5 in which the first monomer component and the second monomer component contain a vinyl monomer having a bridged cyclic structure are superior in pulverizability to Comparative Example 1 in which the first monomer component and the second monomer component do not contain a vinyl monomer having a bridged cyclic structure.

[0185] Also, according to Examples 1 to 5, it can be seen that the pulverizability improves as the content ratio of the vinyl monomer having a bridged cyclic structure increases with respect to the total amount of the first monomer component and the second monomer component.

[0186]

Table 1

[0187]

Table 2

Claims

1. comprising a low molecular weight polymer and a high molecular weight polymer, wherein the weight average molecular weight of the low molecular weight polymer is less than 25,000, the weight average molecular weight of the high molecular weight polymer is 25,000 or more, the low molecular weight polymer is a polymer of a first monomer component, the high molecular weight polymer is a polymer of a second monomer component, at least one of the first monomer component and the second monomer component contains a vinyl monomer having a bridged cyclic structure, a binder for a pulverized toner.

2. The binder for a pulverized toner according to claim 1, wherein both the first monomer component and the second monomer component contain a vinyl monomer having a bridged cyclic structure.

3. In the first monomer component, the content ratio of the vinyl monomer having a bridged cyclic structure is 5% by mass to 60% by mass, In the second monomer component, the content ratio of the vinyl monomer having a bridged cyclic structure is 5% by mass to 60% by mass, the binder for a pulverized toner according to claim 2.

4. The binder for a pulverized toner according to claim 1, wherein the vinyl monomer having a bridged cyclic structure is isobornyl (meth)acrylate.

5. The binder for a pulverized toner according to claim 1, wherein the first monomer component and / or the second monomer component contains a (meth)acrylate ester having an alkyl group having 8 to 22 carbon atoms.

6. The binder for a pulverized toner according to claim 1, wherein the first monomer component and / or the second monomer component contains an aromatic vinyl monomer.

7. The binder for a pulverized toner according to claim 1, wherein the first monomer component and / or the second monomer component contains a biomass-derived monomer.

8. The binder for a pulverized toner according to claim 7, wherein the biomass content is 10% or more and 70% or less.

9. A pulverized toner containing the binder for a pulverized toner according to any one of claims 1 to 8.

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