JP6519184B2 - Polylactic acid resin fine particles - Google Patents

Description

  The present invention relates to polylactic acid based resin fine particles using meso lactide.

  BACKGROUND ART With the recent increase in awareness of environmental problems, development of products using synthetic resins composed of natural materials or biomass-derived materials has been actively conducted. Among them, the polylactic acid-based resin is a resin that can be obtained using lactic acid obtained by fermenting biomass such as corn starch as a synthetic raw material, and various application development has been carried out most actively.

  The polylactic acid-based resin is obtained by dehydration condensation of lactic acid or ring-opening polymerization of lactide. Among them, in the case of dehydration condensation of lactic acid, only a low molecular weight polylactic acid-based resin is obtained, and the required characteristics in various applications can not be satisfied. Therefore, ring-opening polymerization of lactide that can be controlled in molecular weight to obtain a polylactic acid-based resin of high molecular weight is used.

  Polylactic acid composed of L-lactic acid or D-lactic acid exhibits crystallinity, and in particular, exhibits high heat resistance by being stereocomplexed, and thus is used as a resin for fibers and a resin for molded bodies. On the other hand, polylactic acid obtained by mixing L-lactic acid and D-lactic acid becomes amorphous. Amorphous polylactic acid is superior to crystalline polylactic acid in solvent solubility, low-temperature processability, and biodegradability, and it should be used in paints, adhesives, inks, etc. in the form of solution or melt. (See, for example, Patent Documents 1 and 2).

  The non-crystalline polylactic acid is processed into fine particle form (polylactic acid based resin fine particles) in addition to paint and adhesive in solution form or melt form, and then used in various applications such as powder paint, toner and cosmetic additives. It is also expected to be used for the purpose.

At present, the demand for low-temperature melting is increasing for energy saving, and in polylactic acid-based resin fine particles, it is required to achieve both low-temperature melting and higher blocking resistance during storage. In addition, when the low-temperature meltability is enhanced, the quality change over time due to hydrolysis occurs more remarkably, and it has been found to be a fatal problem.
The present invention is a combination of low-temperature melting property and blocking resistance of polylactic acid resin fine particles in various applications such as coating materials such as hot melt adhesive and powder coating, toner, paste, ink and cosmetic additives, and stability over time The task is to improve the quality.

The means for solving the problems are as follows. That is,
The polylactic acid based resin fine particles of the present invention are
Contains polylactic acid resin as the main component,
The total content of lactide and lactic acid is 0.30% by mass or less,
At least one of the following conditions (1) and (2) is satisfied:
It is characterized by
Condition (1): The molar ratio (L-lactic acid residue / D-lactic acid residue) of L-lactic acid residue and D-lactic acid residue in the polylactic acid-based resin is 1 or more and 7 or less, and the D- The main component of the lactic acid residue is a meso-lactide-derived D-lactic acid residue.
Condition (2): the molar ratio of D-lactic acid residue to L-lactic acid residue (D-lactic acid residue / L-lactic acid residue) in the polylactic acid-based resin is 1 or more and 7 or less, and the L- The main component of a lactic acid residue is an L-lactic acid residue derived from meso lactide.

  According to the present invention, the above-mentioned various problems in the prior art can be solved, and it is possible to use polylactic acid resin fine particles in various applications such as coating materials such as hot melt adhesive and powder coating, toners, pastes, inks and cosmetic additives. It is possible to improve both the low temperature melting property and the blocking resistance, and the stability over time.

FIG. 1 is a ¹³ C-NMR spectrum of polylactic acid.

(Poly lactic acid resin fine particles)
The polylactic acid-based resin fine particle of the present invention contains a polylactic acid-based resin as a main component, and the total content of lactide and lactic acid is 0.30% by mass or less, and, if necessary, other components. contains.

The polylactic acid-based resin fine particles satisfy at least one of the following condition (1) and condition (2).
Condition (1): The molar ratio (L-lactic acid residue / D-lactic acid residue) of L-lactic acid residue and D-lactic acid residue in the polylactic acid-based resin is 1 or more and 7 or less, and the D- The main component of the lactic acid residue is a meso-lactide-derived D-lactic acid residue.
Condition (2): the molar ratio of D-lactic acid residue to L-lactic acid residue (D-lactic acid residue / L-lactic acid residue) in the polylactic acid-based resin is 1 or more and 7 or less, and the L- The main component of a lactic acid residue is an L-lactic acid residue derived from meso lactide.

As a result of intensive investigations, the present inventors found that the molar ratio of L-lactic acid residue and D-lactic acid residue in the polylactic acid resin is within a specific range, and that of the monomer residues in the polylactic acid resin. In the arrangement, the higher the proportion of the L-lactic acid residue and the D-lactic acid residue adjacent to each other, the higher the polylactic acid-based resin fine particle has a low level of low-temperature melting property, and further, in the polylactic acid-based resin fine particle It was found that the lower the total content of lactide and lactic acid, the smaller the fluctuation of quality over time due to hydrolysis.
When the polylactic acid-based resin satisfies the condition (1), the polylactic acid-based resin fine particles have a high level of low-temperature melting property. On the other hand, since L-lactic acid and D-lactic acid have an optical isomer relationship, even if L-lactic acid and D-lactic acid are replaced in the polylactic acid-based resin, the physical properties are the same as those of the polylactic acid-based resin before replacement. Characteristics are obtained. The condition (1) and the condition (2) are in a relationship in which L-lactic acid and D-lactic acid are interchanged. Therefore, even when the polylactic acid-based resin satisfies the above condition (2), the polylactic acid-based resin fine particles have a high level of low-temperature melting property. That is, the condition (1) and the condition (2) have the same technical meaning.

Whether or not the D-lactic acid residue in the polylactic acid-based resin is a meso-lactide-derived D-lactic acid residue, and the ratio thereof can be confirmed by structural analysis of the polymer.
Whether or not the L-lactic acid residue in the polylactic acid-based resin is a meso-lactide-derived L-lactic acid residue, and the ratio thereof can be confirmed by structural analysis of the polymer.
The method of structural analysis of the polymer will be described later.

The molar ratio of the D-lactic acid residue and the L-lactic acid residue can be determined, for example, by the following method.
The sample is added to a mixed solvent of pure water and 1N sodium hydroxide and isopropyl alcohol, and the mixture is heated and stirred at 70 ° C. to hydrolyze. Subsequently, after filtering and removing the solid content in a liquid, sulfuric acid is added and it neutralizes and it obtains the aqueous solution containing L-lactic acid and D-lactic acid. This aqueous solution is measured by high performance liquid chromatography (HPLC) using a chiral ligand exchange column SUMICHIRAL OA-5000 (manufactured by Sumika Chemical Analysis Service, Ltd.), and the peak area derived from L-lactic acid and D-lactic acid A molar ratio (L-lactic acid residue / D-lactic acid residue) or a molar ratio (D-lactic acid residue / L-lactic acid residue) is calculated from the ratio of the peak area derived from.

In the condition (1), when the D-lactic acid residue is mainly composed of a meso-lactide-derived D-lactic acid residue, the polylactic acid-based resin fine particles exhibit good low-temperature melting property. here. The "main component" means that 50% by mass or more of D-lactic acid residues constituting the polylactic acid-based resin is contained, and preferably 65% by mass or more, more preferably 80% by mass or more. is there.
In the condition (2), when the L-lactic acid residue is mainly composed of a meso-lactide-derived L-lactic acid residue, the polylactic acid-based resin fine particles exhibit good low-temperature melting property. here. The "main component" is to occupy 50% by mass or more of the L-lactic acid residue constituting the polylactic acid-based resin, preferably 65% by mass or more, more preferably 80% by mass or more is there.

The molar ratio (L-lactic acid residue / D-lactic acid residue) in the condition (1) is preferably 1 or more and 5.67 or less. In the condition (1), when the molar ratio (L-lactic acid residue / D-lactic acid residue) is within the preferable range, the polylactic acid-based resin is excellent in low-temperature melting property and is to be a general-purpose solvent Solubility of the above, and there is no change in physical properties in long-term storage.
The molar ratio (D-lactic acid residue / L-lactic acid residue) in the condition (2) is preferably 1 or more and 5.67 or less. In the condition (2), when the molar ratio (D-lactic acid residue / L-lactic acid residue) is within the preferable range, the polylactic acid-based resin is excellent in low-temperature melting property, and to a general-purpose solvent Solubility of the above, and there is no change in physical properties in long-term storage.

<Poly lactic acid resin>
The said polylactic acid type-resin particle | grains show favorable low-temperature melting property by containing polylactic acid type-resin as a main component. Here, the "main component" means that the content is 50% by mass or more of the polylactic acid resin fine particles.
It is preferable that the said polylactic acid-type resin microparticles contain 65 mass% or more of said polylactic acid-type resin, and it is more preferable to contain 80 mass% or more.

  The polylactic acid-based resin can be obtained, for example, by ring opening polycondensation of lactide using a hydroxyl group-containing compound as an initiator.

<< Hydroxyl group containing compound >>
There is no restriction | limiting in particular as said hydroxyl-containing compound used as said initiator, According to the objective, it can select suitably, For example, aliphatic polyol, hydroxycarboxylic acid, polyester polyol etc. are mentioned.
Examples of the aliphatic polyol include ethylene glycol, glycerin and pentaerythritol.
Examples of the hydroxycarboxylic acid include glycolic acid, lactic acid and glyceric acid.
Examples of the polyester polyol include polyester polyols obtained from succinic acid, adipic acid and the like, and butanediol, hexanediol and the like.
Among these, the hydroxyl group-containing compound is preferably ethylene glycol from the viewpoint of versatility.

When a diol such as ethylene glycol is used as the hydroxyl group-containing compound, a lactide ring-opened polymer having hydroxyl groups at both ends can be obtained.
The polylactic acid-based resin may be obtained by chain extension of the lactide ring-opening polymer having a hydroxyl group at both ends with at least one of a dicarboxylic acid, a diisocyanate, and a diamine.
Examples of the dicarboxylic acids include succinic acid and adipic acid.
Examples of the diisocyanate include hexamethylene diisocyanate and 4,4'-diphenylmethane diisocyanate.
Examples of the diamine include ethylene diamine and paraphenylene diamine.

<< lactide >>
In the production of the polylactic acid-based resin, meso-lactide is used as an essential component, but in addition, L-lactide and D-lactide can be used in such a range that at least one of the conditions (1) and (2) is satisfied. You may use.
From the viewpoint of economic rationality, it is preferable that, as the meso-lactide, L-lactic acid is a racemized L-lactic acid in the process of obtaining L-lactide, which is a by-product.

In the production of the polylactic acid-based resin, hydroxycarboxylic acid, dicarboxylic acid, polyol, ε-caprolactone and the like can be used as a copolymerization component other than lactide.
Examples of the hydroxycarboxylic acid include lactic acid, glycolic acid, 2-hydroxyisobutyric acid, 3-hydroxybutyric acid, 16-hydroxyhexadecanoic acid, 2-hydroxy-2-methylbutyric acid, 10-hydroxystearic acid, malic acid and citric acid. An acid etc. are mentioned.
As said dicarboxylic acid, a succinic acid etc. are mentioned, for example.
Examples of the polyol include ethylene glycol and the like.

A catalyst may be used in the ring opening polycondensation.
Examples of the catalyst include organic tin compounds, organic titanium compounds, organic tin halide compounds and the like.
The amount of the catalyst used in the ring opening polycondensation is, for example, 100 ppm to 1,000 ppm relative to the monomer.

As a polymerization temperature of the said ring-opening polycondensation, 150 degreeC-220 degreeC etc. are mentioned, for example.
As time of the said ring-opening polycondensation, 1 hour-6 hours etc. are mentioned, for example.
The ring-opening polycondensation is preferably performed under an inert gas atmosphere such as nitrogen gas.

<< number average molecular weight >>
There is no restriction | limiting in particular as a number average molecular weight of the said polylactic acid-type resin, Although it can select suitably according to the objective, 9,000 or more is preferable, 9,000-40,000 is more preferable, 10,000 -35,000 are more preferable, and 11,000-30,000 are especially preferable. When the number average molecular weight is less than 9,000, the blocking resistance may decrease, and when it exceeds 40,000, a coating film is formed using the polylactic acid resin fine particles. And the degree of gloss may decrease.

The said number average molecular weight can be measured by the following method, for example.
The sample is dissolved in tetrahydrofuran so that the sample concentration is about 0.5 mass%, and the sample filtered through a polytetrafluoroethylene membrane filter with a pore size of 0.5 μm is used as a measurement sample. Measure at 30 ° C. using a Waters gel permeation chromatograph (GPC) Alliance GPC system. A polystyrene standard is used as a molecular weight standard sample.

<Content of lactide and lactic acid>
The total content of lactide and lactic acid in the polylactic acid-based resin fine particles is 0.30% by mass or less, and preferably 0.20% by mass or less. When the total content of the lactide and the lactic acid exceeds 0.30% by mass, the temporal stability and the blocking resistance deteriorate.

  As a method of reducing the total content of lactide and lactic acid in the polylactic acid resin fine particles, for example, a method of removing the lactide and the lactic acid by reducing the pressure of the polylactic acid resin after polymerization, the polylactic acid resin The pellet after polymerization is immersed in warm water to extract and remove the lactide and the lactic acid, and a method of removing the lactide and the lactic acid in the step of preparing resin fine particles. Among these, the method of removing the lactide and the lactic acid in the step of preparing the resin fine particles is particularly preferable. In the method of removing the lactide and the lactic acid by reducing the pressure of the polylactic acid-based resin after polymerization and removing the lactide and the lactic acid by immersing pellets after the polymerization of the polylactic acid-based resin in warm water, The total content of lactide and lactic acid may fail to achieve 0.30% by mass or less. The process of preparing resin fine particles will be described later.

<Glass transition temperature>
There is no restriction | limiting in particular as a glass transition temperature of the said polylactic acid-type resin fine particle, Although it can select suitably according to the objective, 40.0 degreeC or more is preferable, 42.0 degreeC or more is more preferable, 45.0 C. or higher is particularly preferred. When the glass transition temperature is less than 40.0 ° C., the blocking resistance may be reduced.
The glass transition temperature can be controlled by the reduced viscosity of the polylactic acid-based resin and the selection of the copolymerization component.

  The glass transition temperature is, for example, 5 mg of a sample placed in an aluminum sample pan and sealed, using a differential scanning calorimeter DSC-220 manufactured by Seiko Instruments Inc., at a rate of 20 ° C./min to −20 ° C. to 120 ° C. The temperature is raised to ° C., and after cooling at an arbitrary rate, the temperature is raised from -20 ° C. to 120 ° C. at a heating rate of 10 ° C./min, and the glass transition temperature can be determined by the midpoint method.

<1/2 outflow temperature>
There is no restriction | limiting in particular as 1/2 outflow temperature of the said polylactic acid-type resin fine particle, Although it can select suitably according to the objective, 80 to 120 degreeC is preferable and 90 to 110 degreeC is more preferable. . When the 1/2 outflow temperature is less than 80 ° C., the offset resistance may be deteriorated, and when it is more than 120 ° C., the low temperature melting property may be deteriorated or the gloss may be deteriorated. It is advantageous at the point of coexistence of low temperature melting property and offset resistance that the said 1/2 outflow temperature is in the said more preferable range.

  The 1/2 outflow temperature can be determined, for example, using an elevated flow tester (CFT-500) (manufactured by Shimadzu Corporation). In that case, 1 g of the pelletized sample is melted and flowed under the conditions of die hole diameter 0.5 mm, die length 1 mm, weight 30 kg, heating rate 3 ° C./min, measurement start temperature 50 ° C., end temperature 200 ° C. The temperature corresponding to 1⁄2 of the height of the outflow end point from the outflow start point at that time is taken as the 1⁄2 outflow temperature.

<Volume average particle size>
The volume average particle diameter of the polylactic acid based resin fine particles can be appropriately selected according to the application.
For example, in the case of toner use, it is preferably 3 μm to 10 μm. If the volume average particle diameter of the toner is less than 3 μm, the toner may be fused to the surface of the carrier during long-term stirring in the developing device with a two-component developer, and the chargeability of the carrier may be reduced. It becomes difficult to obtain high resolution and high quality images.

  Moreover, in the case of a hot-melt-adhesive use, it is preferable that they are 3 micrometers or more and 20 micrometers or less. If the particle size is too small, storage stability may be poor, and the particles may be fused together to make the particle size non-uniform, which may make low-temperature melting in a short time difficult. On the other hand, if the particle size is too large, uniform fine processing may be difficult.

  In the case of powder coating applications, the thickness is preferably 10 μm or more and 50 μm or less. If the volume average particle diameter of the powder coating is less than 10 μm, the fluidity may be insufficient, and uniform coating may be difficult. If it exceeds 50 μm, high gloss may not be obtained. .

  The volume average particle diameter can be adjusted by the production conditions at the time of granulation and the like.

<Volume Average Particle Size (Dv) / Number Average Particle Size (Dn)>
Although the particle size distribution (Dv / Dn) of the said polylactic acid-type resin fine particle can be suitably selected according to a use, it is preferable that it is 1.3 or less.

  In particular, in the case of toner use, it is more preferable that the ratio is 1.25 or less. If the particle size distribution (Dv / Dn) exceeds 1.25, the two-component developer may cause the toner to fuse to the surface of the carrier during long-term stirring in the developing device, which may lower the chargeability of the carrier, resulting in high resolution. It can be difficult to obtain high quality images with images.

  In the case of hot melt adhesive applications, the particle size distribution (Dv / Dn) is more preferably 1.25 or less. If the particle size distribution is too wide, low temperature melting in a short time becomes difficult, and the storage stability may be poor due to an increase in the proportion of particles having a particle size of less than 1 μm.

  In the case of powder coating applications, when the particle size distribution (Dv / Dn) exceeds 1.3, the flow characteristics and the uniformity of the film thickness may be deteriorated.

  The particle size distribution can be adjusted by the production conditions at the time of granulation and the like.

  The measurement of the volume average particle diameter (Dv) and the ratio of the volume average particle diameter (Dv) to the number average particle diameter (Dn) (particle size distribution (Dv / Dn)) can be carried out, for example, using It can be carried out using Sizer III "manufactured by Beckman Coulter. In that case, it measures by aperture diameter 100 micrometers, and analyzes with analysis software (Beckman CoulterMutlisizer 3 Version 3.51).

<Method for producing polylactic acid resin fine particles>
There is no restriction | limiting in particular as a manufacturing method of the said polylactic acid-type resin microparticles | fine-particles, According to the objective, it can select suitably, For example, a grinding method, an aggregation method, the solution suspension method etc. are mentioned. Among these, the aggregation method and the dissolution suspension method are preferable in that the content of lactic acid and lactide can be reduced.

<< Crushing method >>
The pulverization method is, for example, a method of obtaining the polylactic acid-based resin fine particles by melting or kneading raw materials such as the polylactic acid-based resin and the like, pulverizing, classifying and the like.
First, raw materials such as the polylactic acid-based resin are mixed, and the obtained mixture is charged into a melt kneader and melt-kneaded. Then, the kneaded material obtained by the said melt-kneading is grind | pulverized. At this time, it is preferable to use a system in which the collision plate is made to collide with a collision plate to be crushed in a jet air flow, particles are made to collide with each other in a jet air flow to be ground, or a small gap of mechanically rotating rotor and stator is used. . Furthermore, the pulverized product obtained by the pulverization is classified to prepare particles of a predetermined particle size, to obtain the polylactic acid based resin fine particles.

<< flocculation method >>
As the aggregation method, first, a resin fine particle dispersion in which the polylactic acid-based resin is dispersed in an aqueous medium is prepared. Separately, a dispersion in which an additive such as a filler is dispersed in an aqueous medium is prepared, and after mixing with the fine resin particle dispersion, it is coagulated to a desired particle size and thermally fused to obtain the above-mentioned fine polylactic acid resin fine particles. .

<< Dissolution suspension method >>
Examples of the lysis suspension method include the following methods.
The raw material such as the polylactic acid-based resin is dissolved or dispersed in an organic solvent, and the obtained dissolved or dispersed liquid is dispersed or emulsified in an aqueous medium in which resin fine particles are dispersed, and then the organic solvent is removed. .
At the time of the dispersion or emulsification, a surfactant or the like is suitably used as a particle size regulator. In order to remove the organic solvent from the obtained emulsified dispersion, a method of gradually raising the temperature of the whole system and completely evaporating and removing the organic solvent in the droplets may be mentioned. Thereafter, the crude dispersion is roughly separated by centrifugation, the step of washing the emulsified dispersion in a washing tank, and the step of drying with a warm air drier are repeated, the organic solvent is removed, dried and classified. Resin fine particles can be obtained. In order to reduce the content of lactide and lactic acid more effectively, heating may be performed during the dispersion or emulsification.

  Further, in order to enhance the flowability and the storage stability of the polylactic acid based resin fine particles, inorganic fine particles such as hydrophobic silica fine powder may be further added to and mixed with the resin fine particles manufactured as described above. Examples of mixing equipment that can be used include a V-type mixer, a rocking mixer, a Loedige mixer, a Nauta mixer, and a Henschel mixer. Next, the particles are passed through a sieve of 250 mesh or more to remove coarse particles and aggregated particles, and the polylactic acid based resin fine particles are obtained.

The polylactic acid-based resin fine particle is a hot melt adhesive, coating material (for example, powder coating), toner, paste, ink, cosmetic additive, spacer, various carriers, magnetic fluid, electrorheological fluid, electrostatic / electrostatic charge prevention Agent, magnetism, radiation, heat ray, ultraviolet ray shielding material, plastic magnet, piezoelectric material, pyroelectric material, dielectric, photocatalyst, magnetic powder for cancer thermal treatment, reflective material, abrasive, sliding property improvement material, etc. .
The polylactic acid-based resin fine particles are expected to contribute to the industry in terms of energy saving and improvement of working efficiency due to good meltability in a lower temperature range than conventional.

(toner)
Hereinafter, a toner as an application example of the polylactic acid based resin fine particle will be described.
The toner contains the polylactic acid-based resin as a main component, the total content of lactide and lactic acid is 0.30% by mass or less, and further contains other components as necessary.
The toner satisfies at least one of the condition (1) and the condition (2).

  The toner has low-temperature fixability and blocking resistance, and is excellent in the stability over time of the fixing temperature range.

The toner exhibits good low-temperature melting property by containing the polylactic acid-based resin as a main component. Here, the “main component” means that the content is 50% by mass or more of the toner.
The toner preferably contains the polylactic acid-based resin at 65% by mass or more, and more preferably 80% by mass or more.

<Other ingredients>
Examples of the other components include colorants, release agents, charge control agents, external additives, flowability improvers, cleanability improvers, magnetic materials, metal soaps and the like.

<< Colorant >>
There is no restriction | limiting in particular as said coloring agent, According to the objective, it can select suitably.
There is no restriction | limiting in particular as content of the said coloring agent in the said toner, Although it can select suitably according to the objective, 1 mass%-15 mass% are preferable, and 3 mass%-10 mass% are more preferable. When the content is less than 1% by mass, the coloring power of the toner may be decreased. When the content is more than 15% by mass, poor dispersion of the pigment in the toner may occur to reduce the coloring power and the electricity of the toner. It may cause deterioration of the characteristics.

  The colorant may be used as a master batch complexed with a resin. The masterbatch can be manufactured by mixing or kneading the resin and the colorant under high shear force. For mixing or kneading, for example, a high shear dispersion device such as a triple roll mill can be used.

<< mold release agent >>
There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably, For example, carnauba wax, polyethylene wax, ester wax etc. are mentioned.

  There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 40 to 120 degreeC is preferable and 70 to 90 degreeC is more preferable. When the melting point is less than 40 ° C., the blocking resistance may be lowered, and when it is more than 120 ° C., cold offset may be easily caused when fixing at a low temperature.

  There is no restriction | limiting in particular as content of the said mold release agent in the said toner, Although it can select suitably according to the objective, 1 mass%-20 mass% are preferable with respect to a toner resin component, 3 mass%- 10 mass% is more preferable. When the content is less than 1% by mass, the offset prevention effect may be insufficient, and when it exceeds 20% by mass, the transferability and the durability may be reduced.

<< Charge control agent >>
In order to provide the toner with an appropriate chargeability, it is also possible to include a charge control agent in the toner as needed.
Any known charge control agent can be used as the charge control agent.

  The charge control agent may be dissolved or dispersed in a solution or dispersion of a toner material after being melt-kneaded with a master batch in which the colorant and the resin are complexed, and the organic solvent together with each component of the toner It may be added directly when dissolving or dispersing the toner material, or may be fixed to the toner surface after the toner particles are produced.

<< External additive >>
Various external additives can be added to the toner for the purpose of flowability modification, charge amount adjustment, adjustment of electrical characteristics, and the like.
There is no restriction | limiting in particular as said external additive, According to the objective, it can select suitably from well-known things.

  There is no restriction | limiting in particular as an average particle diameter of the primary particle of the said external additive, Although it can select suitably according to the objective, 1 nm-100 nm are preferable, and 3 nm-70 nm are more preferable.

  There is no restriction | limiting in particular as content of the said external additive in the said toner, Although it can select suitably according to the objective, 0.1 mass%-5 mass% are preferable, 0.3 mass%-3 mass % Is more preferable.

  The toner is not particularly limited in its shape, size and the like, and may be appropriately selected according to the purpose. However, the average circularity, volume average particle diameter, volume average particle diameter and number of particles as described below It is preferable to have a ratio to the average particle diameter (volume average particle diameter / number average particle diameter) or the like.

  The average circularity is a value obtained by dividing the peripheral length of the equivalent circle having the same projected area as the shape of the toner by the peripheral length of the actual particles, and is preferably 0.900 to 0.980, and 0.950 to 0.975. Is more preferred.

  There is no restriction | limiting in particular as a volume average particle diameter of the said toner, Although it can select suitably according to the objective, 3 micrometers-10 micrometers are preferable, and 3 micrometers-8 micrometers are more preferable.

  The ratio of volume average particle diameter to number average particle diameter (volume average particle diameter / number average particle diameter) in the toner is preferably 1.00 to 1.25, and more preferably 1.10 to 1.25.

(Developer)
The toner can be used as a developer containing other components such as a carrier appropriately selected.
The developer may be a one-component developer or a two-component developer, but when it is used in a high-speed printer or the like compatible with the recent improvement of the information processing speed, the life is improved The two-component developer is preferred in view of the above.

<Carrier>
There is no restriction | limiting in particular as said carrier, According to the objective, it can select suitably.

10 micrometers-100 micrometers are preferable, and, as for the volume average particle diameter of the said carrier, 20 micrometers-65 micrometers are more preferable.
The volume resistivity of the carrier is preferably 9 [log (Ω · cm)] or more and 16 [log (Ω · cm)] or less, and 10 [log (Ω · cm)] or more 14 [log (Ω · cm)] The following are more preferable.

  When the developer is a two-component developer, the mixing ratio of the toner and the carrier in the two-component developer is 2.0% by mass to 12.0% by mass of the toner with respect to the carrier. Is preferably, and more preferably 2.5% by mass to 10.0% by mass.

  EXAMPLES Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples. The term "parts" refers to "parts by mass" unless otherwise specified. "%" Represents "% by mass" unless otherwise specified.

  In addition, the measurement and evaluation method employ | adopted in this specification are as follows.

(1) Number Average Molecular Weight A sample was dissolved in tetrahydrofuran so that the sample concentration was about 0.5%, and filtered through a polytetrafluoroethylene membrane filter with a pore size of 0.5 μm to obtain a measurement sample. Measurement was carried out at 30 ° C. using a Waters gel permeation chromatograph (GPC) Alliance GPC system. A polystyrene standard was used as a molecular weight standard sample.

(2) Polymer structure analysis A sample is dissolved in chloroform-d at a concentration of 200 mg / 3 mL, 13 C-NMR analysis is performed by Bruker's nuclear magnetic resonance analyzer (NMR) "Avance 500" using a BBO probe with a diameter of 10 mm. went. The number of integrations was 512 times, and spin decoupling with 1 H was performed.
At 69.0 ppm-70.0 ppm of the spectrum, a peak derived from the methine group of the polymer is observed. As shown in FIG. 1, the chain distribution differs between polylactic acid consisting only of L-lactide and D-lactide (spectrum a) and polylactic acid using meso-lactide (spectrums b, c, d, e), the latter being more The peak number of splits increases. At this time, for example, when the molar ratio of L-lactic acid residue to D-lactic acid residue (L / D) is 1 or more and 7 or less, the ratio of meso-lactide-derived D-lactic acid residue in D-lactic acid residue increases , The relative peak area of "5" increases. When the proportion occupied by the meso-lactide-derived D-lactic acid residue is 50%, the relative peak area of the “5” peak is 35.3% with respect to the “3” peak.

(3) Content of lactide After dissolving 0.05 g of resin in 2 mL of dichloromethane, 6 mL of acetone was added. The polymer was reprecipitated with 40 mL of hexane and adjusted to 50 mL with acetone. The sample solution after constant volume is filtered with a polytetrafluoroethylene membrane filter with a pore size of 0.50 μm, and the filtrate is GC-MS (GC: HP-7890 manufactured by Agilent, MS: HP-5975 C manufactured by Agilent) It analyzed by. Since peaks of D-lactide and L-lactide were detected, two peak area values were added and used for quantification. The calibration curve was prepared by analyzing an acetone solution of L-lactide by GC-MS.
〔Measurement condition〕
Column: Stabilwax (30 m in length, 0.25 mm in inner diameter, 0.50 μm in film thickness) manufactured by Restek
・ Inlet temperature: 220 ° C
・ Column flow rate: 1.0 mL / min
Split ratio: 10
· Column bath temperature: 50 ° C (hold for 2 minutes) → 15 ° C / min → 230 ° C (hold for 5 minutes)
・ Measurement mass number: m / z 56
・ Ionization energy: 70 eV
-Ion source temperature: 230 ° C
Injection volume: 1 μL

(4) Content of lactic acid 1 mL of a solution in which 1 g of a sample was dissolved in 10 g of THF was charged into 10 g of ion exchanged water and stirred. Next, the precipitate was removed using filter paper and a membrane filter, and the filtrate was made up to 50 mL with ion exchanged water. The sample solution after constant volume was analyzed by HPLC (manufactured by Shiseido Co., Ltd., NANO-SPACE SI-2).
[Measurement condition]
Mobile phase: acetonitrile / 0.05 M aqueous potassium dihydrogen phosphate solution = 1 vol% / 99 vol%
Detector: Photodiode array detector (manufactured by Shiseido Co., Ltd., attached to NANO-SPACE SI-2), wavelength 210 nm
Column: AQUASIL C18 (manufactured by Thermo Fisher Scientific, particle diameter 5 μm, length 250 mm, inner diameter 4.6 mm)
・ Column bath temperature: 40 ° C
・ Flow rate: 1.25mL / min

(5) Method of measuring molar ratio of L-lactic acid residue and D-lactic acid residue (L-lactic acid residue / D-lactic acid residue) Add the sample to a mixed solvent of pure water and 1N sodium hydroxide and isopropyl alcohol The mixture was heated and stirred at 70 ° C. for hydrolysis. Subsequently, after filtering and removing the solid content in a liquid, sulfuric acid was added and it neutralized, and obtained the aqueous solution containing L-lactic acid and D-lactic acid. This aqueous solution is measured by high performance liquid chromatography (HPLC) using a chiral ligand exchange column SUMICHIRAL OA-5000 (manufactured by Sumika Chemical Analysis Service, Ltd.), and the peak area derived from L-lactic acid and D-lactic acid The molar ratio (L-lactic acid residue / D-lactic acid residue) was calculated from the ratio of the peak area derived from.

(6) Glass transition temperature (Tg)
5 mg of the sample is put in an aluminum sample pan and sealed, and the temperature is raised from −20 ° C. to 120 ° C. at a rate of 20 ° C./min using a differential scanning calorimeter DSC-220 manufactured by Seiko Instruments Inc. After cooling at a speed, the temperature was raised from -20 ° C. to 120 ° C. at a heating rate of 10 ° C./min, and the glass transition temperature was determined by the midpoint method.

(7) Particle Size of Polylactic Acid-Based Resin Fine Particles Volume average particle size (Dv) and ratio of volume average particle size (Dv) to number average particle size (Dn) (volume average particle size / number average particle size) A particle size measurement device ("Multisizer III", manufactured by Beckman Coulter, Inc.) was used for the measurement of. It measured by aperture diameter 100 micrometers, and analyzed with analysis software (Beckman CoulterMutlisizer 3 Version 3.51).

(8) 1/2 outflow temperature The 1/2 outflow temperature was determined using an elevated flow tester (CFT-500) (manufactured by Shimadzu Corporation). Start of flow when 1 g of pelletized sample is melted and flowed out under the conditions of die hole diameter 0.5 mm, die length 1 mm, weight 30 kg, heating rate 3 ° C./min, measurement start temperature 50 ° C., end temperature 200 ° C. The temperature corresponding to 1/2 of the height of the outflow end point from the point was taken as 1/2 outflow temperature.

Hereinafter, the abbreviations of the compounds shown in the texts and tables in the examples respectively indicate the following compounds.
M-LD: meso lactide L-LD: L-lactide D-LD: D-lactide EG: ethylene glycol

(Production example)
<Synthesis of Polylactic Acid Resin (1 to 15)>
Lactide (M-LD, D-LD, L-LD) and polyol (EG) are charged as shown in Table 1 below into a 500 mL glass flask equipped with a thermometer, a stirrer, and a Liebig condenser, and 2 as a catalyst. -0.084 parts of tin (II) ethylhexanoate and 0.420 parts of triethyl phosphonoacetate as a catalyst deactivator were added, and the solution was decompressed to 10 mmHg or less at room temperature and dehydrated for 30 minutes. The pressure was returned to normal pressure with nitrogen gas, and the temperature was raised to 180 ° C. while being appropriately stirred under a nitrogen stream, and the mixture was stirred for 3 hours. Thereafter, the pressure of the system was reduced to distill off low molecular weight compounds such as unreacted lactide. After about 20 minutes, distillation of the low molecular weight compound was stopped, the pressure was released, and the resultant was taken out as a Teflon sheet or the like to obtain a resin. The composition and number average molecular weight of the obtained polylactic acid resin (1 to 15) are shown in Table 1.

Example 1
<Preparation of Polylactic Acid-Based Resin Fine Particles 1>
-Preparation of styrene acrylic resin fine particle dispersion-
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen introduction pipe, 1.6 parts of sodium dodecyl sulfate and 486 parts of ion exchange water were placed and heated to 80 ° C. with stirring to dissolve. Thereafter, 2.8 parts of potassium persulfate dissolved in 109 parts of ion-exchanged water is added to the reaction vessel, and after 15 minutes, a mixed solution of 180 parts of styrene and 20 parts of butyl acrylate is added for 90 minutes. It dripped over. Thereafter, the temperature was kept at 80 ° C. for 60 minutes to carry out a polymerization reaction, followed by cooling to obtain a styrene acrylic resin fine particle dispersion. The volume average particle diameter of the particles contained in the styrene acrylic resin fine particle dispersion was 78 nm, the weight average molecular weight of the resin component was 220,000, and the Tg was 85 ° C.

-Preparation of aqueous phase-
Mix and stir 990 parts of water, 37 parts of a 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, Sanyo Chemical Industries, Ltd.), 90 parts of ethyl acetate, and 83 parts of a styrene acrylic resin fine particle dispersion Water phase 1 was obtained.

-Preparation of polylactic acid resin fine particle 1-
A resin solution 1 was prepared by mixing and stirring 180 parts of the polylactic acid-based resin 1 and 180 parts of ethyl acetate.
Next, 90 parts of the resin solution 1 was placed in a container. In a separate container, 150 parts of the aqueous phase 1 is added, 90 parts of the resin solution 1 is added while stirring at 8,000 rpm at 50 ° C. using a TK homomixer, and mixed for 2 minutes. Emulsified slurry 1 was obtained. Furthermore, 100 parts of the emulsified slurry 1 is charged in a Kolben set with a stirrer and a thermometer, desolvated at 50 ° C. for 10 hours while stirring at a stirring peripheral speed of 20 m / min, and then washed, filtered and dried. went.
Thereafter, the particles were sieved with a mesh of 75 μm to prepare polylactic acid based resin fine particles 1 of Example 1. Physical properties of the obtained polylactic acid based resin fine particle 1 are described in Table 2.

(Examples 2 to 10)
<Preparation of Polylactic Acid-Based Resin Fine Particles 2 to 10>
In Example 1, polylactic acid based resin fine particles 2 to 10 were produced in the same manner as in Example 1 except that polylactic acid based resin 1 was replaced with polylactic acid based resin 2 to 10 as shown in Table 2, respectively. did.
Physical properties of the obtained polylactic acid based resin fine particles 2 to 10 are described in Table 2.

(Example 11)
<Preparation of Polylactic Acid-Based Resin Fine Particles 11>
The polylactic acid-based resin fine particles 11 of Example 11 were obtained in the same manner as in Example 1 except that the temperature at the time of stirring by the TK homomixer and the solvent removal temperature were changed to 40 ° C. in Example 1.
Physical properties of the obtained polylactic acid based resin fine particles 11 are described in Table 2.

(Comparative example 1)
<Preparation of Polylactic Acid-Based Resin Fine Particles 12>
A polylactic acid-based resin fine particle 12 was produced in the same manner as in Example 1, except that the polylactic acid-based resin 1 was replaced with the polylactic acid-based resin 11 in Example 1.
Physical properties of the obtained polylactic acid based resin fine particles 12 are described in Table 2.

(Comparative examples 2 to 5)
<Preparation of Polylactic Acid-Based Resin Fine Particles 13 to 16>
In Example 1, polylactic acid based resin fine particles 13 to 16 were produced in the same manner as in Example 1 except that polylactic acid based resin 1 was replaced with polylactic acid based resins 12 to 15 as shown in Table 2, respectively. did.
Physical properties of the obtained polylactic acid based resin fine particles 13 to 16 are described in Table 2.

(Comparative example 6)
<Preparation of Polylactic Acid-Based Resin Fine Particles 17>
A polylactic acid based resin fine particle 17 of Comparative Example 6 was obtained in the same manner as in Example 1 except that the temperature at the time of stirring by the TK homomixer and the solvent removal temperature were changed to 35 ° C. in Example 1.
Physical properties of the obtained polylactic acid resin fine particles 17 are described in Table 2.

(Comparative example 7)
<Preparation of Polylactic Acid-Based Resin Fine Particles 18>
A polylactic acid-based resin fine particle 18 of Comparative Example 7 was obtained in the same manner as in Example 1 except that the temperature at the time of stirring by the TK homomixer and the solvent removal temperature were changed to 30 ° C. in Example 1.
Physical properties of the obtained polylactic acid based resin fine particles 18 are described in Table 2.

<< Heat-resistant storage stability (blocking resistance) >>
Each resin fine particle was filled in a 50 mL glass container, and left in a thermostat at 50 ° C. for 24 hours. The fine resin particles were cooled to 24 ° C., and the penetration (mm) was measured by a penetration test (JIS K 2235-1991), and evaluated based on the following criteria. The larger the penetration value, the better the heat resistant storage stability, and if it is less than 5 mm, there is a high possibility of problems in use.
In the present invention, the penetration is represented by the penetration depth (mm). The results are shown in Table 2.
〔Evaluation criteria〕
○: Penetration degree 15 mm or more △: Penetration degree 5 mm or more, less than 15 mm ×: Penetration degree less than 5 mm

<< Temporal stability >>
Each resin fine particle was placed in a 10 mL glass container, and stored in a constant temperature and humidity chamber at 40 ° C. and 70% relative humidity for 2 weeks. Subsequently, molecular weight measurement was performed by GPC, and the number average molecular weight (Mn) before and after storage was compared. The smaller the decrease in number average molecular weight, the more excellent the temporal stability. The results are shown in Table 2.

(Example 12)
<Production of Toner>
-Preparation of wax dispersion-
100 parts of carnauba wax (molecular weight 1,800, acid value 2.7 mg KOH / g, penetration 1.7 mm (40 ° C.)) and 1,000 parts of ethyl acetate were charged and dissolved at 79 ° C. with stirring After that, it was rapidly cooled to 4 ° C. Using a bead mill (Ultravisco Mill, made by Imex Co., Ltd.), the solution is charged at a liquid transfer rate of 1 kg / hr, at a disk peripheral velocity of 6 m / sec, filled with 80% by volume of zirconia beads with a diameter of 0.5 mm, and dispersed under 3 passes. To prepare a wax dispersion having a volume average particle size of 0.6 μm.

-Preparation of aqueous phase-
990 parts of water, 37 parts of a 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, Sanyo Chemical Industries, Ltd.), 90 parts of ethyl acetate, and 83 parts of the styrene acrylic resin fine particle dispersion are mixed and stirred. , Obtained water phase 2.

-Production of resin fine particles 19 (toner)-
(A mixed solution obtained by mixing and stirring 180 parts of the polylactic acid-based resin 1, 120 parts of the wax dispersion, 12 parts of carbon black (Printex 35, manufactured by Degussa), and 100 parts of ethyl acetate until uniform) Charge to Ultra Bisco Mill, made by Imex Co., Ltd.), pass 3 volumes of 80% by volume of zirconia beads with a particle diameter of 0.5 mm at a disk peripheral velocity of 6 m / sec, at a liquid transfer speed of 1 kg / hour, Was prepared.
Next, 90 parts of the oil phase 2 was placed in a container. In a separate container, 150 parts of the aqueous phase 2 is added, and 90 parts of the oil phase 2 is added while stirring at 8,000 rpm at 50 ° C. using a TK homomixer, and mixed for 2 minutes Emulsified slurry 2 was obtained.
Furthermore, 100 parts of the emulsified slurry 2 is charged in a Kolben set with a stirrer and a thermometer, desolvated at 50 ° C. for 10 hours while stirring at a stirring peripheral speed of 20 m / min, and then washed, filtered and dried. went. Thereafter, the base 2 was produced by sieving with a mesh of 75 μm.

  100 parts of the base 2 thus obtained and 1.0 part of hydrophobic silica (H 2000, manufactured by Clariant Japan) as an external additive, using a Henschel mixer (manufactured by Japan Coke Industry Co., Ltd.), at a circumferential speed of 30 m After 5 cycles of mixing for 30 seconds per second and rest for 1 minute, the resin fine particles 19 of Example 12 were produced by sieving with a mesh of 35 μm.

(Examples 13 to 21 and comparative examples 8 to 12)
<Preparation of resin fine particles 20 to 33 (toner)>
Example 13 is the same as the preparation of the resin fine particle 19 except that the polylactic acid-based resin 1 of the oil phase 2 is replaced by the polylactic acid-based resin 2 to 15 as shown in Table 3 in the preparation of the resin fine particle 19 Resin fine particles 20 to 33 of ̃21 and Comparative Examples 8 to 12 were produced.

(Example 22)
<Preparation of resin fine particles 34 (toner)>
Resin fine particles 34 of Example 22 were obtained in the same manner as the preparation of the resin fine particles 19 except that the temperature during stirring by the TK homomixer and the solvent removal temperature were changed to 40 ° C. in the preparation of the resin fine particles 19.

(Comparative example 13)
<Preparation of resin fine particles 35 (toner)>
Resin fine particles 35 of Comparative Example 13 were obtained in the same manner as the preparation of the resin fine particles 19 except that the temperature during stirring by the TK homomixer and the solvent removal temperature were changed to 35 ° C. in the preparation of the resin fine particles 19.

(Comparative example 14)
<Preparation of resin fine particles 36 (toner)>
Resin fine particles 36 of Comparative Example 14 were obtained in the same manner as the preparation of the resin fine particles 19 except that the temperature at the time of stirring by the TK homomixer and the solvent removal temperature were changed to 30 ° C. in the preparation of the resin fine particles 19.

(Comparative example 15)
<Preparation of resin fine particles 37 (toner)>
Resin fine particles 37 of Comparative Example 15 were obtained in the same manner as the preparation of the resin fine particles 35, except that the number of revolutions at the time of stirring by the TK homomixer was changed to 12,000 rpm in the preparation of the resin fine particles 35.

<Preparation of carrier>
100 parts of silicone resin (organo straight silicone), 5 parts of γ- (2-aminoethyl) aminopropyltrimethoxysilane, 10 parts of carbon black, and 100 parts of toluene are dispersed with a homomixer for 20 minutes to obtain a resin layer coating solution Was prepared. Thereafter, the resin layer coating solution was applied to the surface of 1,000 parts of spherical ferrite having a volume average particle diameter of 35 μm using a fluidized bed type coating apparatus to produce a carrier.

<Preparation of developer>
5 parts by mass of each of the resin fine particles 19 to 37 and 95 parts by mass of the carrier were mixed to prepare developers of Examples 12 to 22 and Comparative Examples 8 to 15.

  The volume average particle size (Dv), the number average particle size (Dn), the ratio (Dv / Dn), the Tg, and the 1⁄2 outflow temperature of the obtained resin fine particles were measured. Further, using each of the obtained developers, the fixing property, the heat resistant storage stability, and the temporal stability were evaluated. The results are shown in Table 3.

<Evaluation method>
<< Fixability >>
Using a tandem-type full-color image forming apparatus (imagio MP C6000, manufactured by Ricoh Co., Ltd.), the adhesion amount of toner after transfer is 0.85 on transfer paper (copy printing paper <70> manufactured by Ricoh Business Expert Co., Ltd.) A solid image (image size 3 cm × 8 cm) of the entire surface of the paper of ± 0.10 mg / cm ² was imaged.
Fixing is performed by changing the temperature of the fixing belt, and the surface of the obtained fixed image is fixed with a ruby needle (tip radius: 260 to 320 μm, tip angle: 60 degrees) using a drawing tester AD-401 (manufactured by Ueshima Seisakusho Co., Ltd.) The image was drawn with a load of 50 g, the drawing surface was strongly rubbed five times with a fiber (Hanicot # 440, manufactured by Hanilon Co., Ltd.), and the fixing belt temperature at which image scraping was almost eliminated was defined as the fixing lower limit temperature. In addition, a solid image was created on the transfer paper at a position 3.0 cm from the leading edge in the sheet passing direction. The speed of passing through the nip portion of the fixing device is 280 mm / s. The lower the fixing lower limit temperature, the better the low temperature fixability.

<< Heat-resistant storage stability (blocking resistance) >>
Each resin fine particle was filled in a 50 mL glass container, and left in a thermostat at 50 ° C. for 24 hours. The fine resin particles were cooled to 24 ° C., and the penetration (mm) was measured by a penetration test (JIS K 2235-1991), and evaluated based on the following criteria. The larger the penetration value, the better the heat resistant storage stability, and if it is less than 5 mm, there is a high possibility of problems in use.
In the present invention, the penetration is represented by the penetration depth (mm).
〔Evaluation criteria〕
○: Penetration degree 15 mm or more △: Penetration degree 5 mm or more, less than 15 mm ×: Penetration degree less than 5 mm

<< Temporal stability >>
In a tandem type full color image forming apparatus (imagio MP C6000, manufactured by Ricoh Co., Ltd.), the adhesion amount of resin fine particles is 0.85 ± 0 on a transfer paper (copy printing paper <70> manufactured by Ricoh Business Expert Co., Ltd.) A solid image (image size 3 cm × 8 cm) of the entire surface of the paper of 10 mg / cm ² was imaged. A solid image is created on the transfer paper at a position 3.0 cm from the leading edge in the sheet passing direction, and the speed of passing through the nip portion of the fixing device is 280 mm / s.
Fixing is performed by changing the temperature of the fixing belt, and the surface of the obtained fixed image is fixed with a ruby needle (tip radius: 260 to 320 μm, tip angle: 60 degrees) using a drawing tester AD-401 (manufactured by Ueshima Seisakusho Co., Ltd.) The image was drawn with a load of 50 g, the drawing surface was strongly rubbed five times with a fiber (Hanicot # 440, manufactured by Hanilon Co., Ltd.), and the fixing belt temperature at which image scraping was almost eliminated was defined as the fixing lower limit temperature. Further, the upper limit temperature at which the hot offset does not occur is defined as the fixing upper limit temperature. The difference between the fixing upper limit temperature and the fixing lower limit temperature determined in this manner was taken as the fixing temperature range.
The same measurement was performed on resin fine particles after storage for 2 weeks in a constant temperature and humidity chamber set at 40 ° C. relative humidity of 70%, and temporal stability was evaluated based on the following criteria from changes in fixing temperature width before and after storage.
〔Evaluation criteria〕
○: (Fixing temperature range before storage-Fixing temperature range after storage) ≦ 5 ° C
Δ: 5 ° C. <(Fixing temperature range before storage−fixing temperature range after storage) ≦ 10 ° C.
×: 10 ° C. <(Fixing temperature range before storage−fixing temperature range after storage)

The resin fine particles of Examples 12 to 22 have low-temperature melting properties (1/2 outflow temperature, fixing lower limit temperature) and resistance due to the type of polylactic acid-based resin and the total content of lactide and lactic acid in the resin fine particles. It was possible to achieve both blocking properties (heat-resistant storage stability) and to improve the temporal stability.
In Comparative Examples 8 to 12, the low temperature melting property was not sufficient due to the type of polylactic acid-based resin.
In Comparative Examples 13 to 15, the blocking resistance and the temporal stability were insufficient due to the decrease in the molecular weight of the polylactic acid-based resin due to the large total content of lactide and lactic acid in the resin fine particles.

The polylactic acid-based resin fine particles of the present invention can be used in hot melt adhesive materials, coating materials (for example, powder coatings), toners, pastes, inks, cosmetic additives, spacers, various carriers, magnetic fluids, electrorheological fluids, electrostatic Antistatic agents, magnetic, radiation, heat rays, ultraviolet rays shielding materials, plastic magnets, piezoelectrics, pyroelectrics, dielectrics, photocatalysts, magnetic powders for cancer thermal treatment, reflective materials, abrasives, sliding property improving materials, etc. Available.
The polylactic acid-based resin fine particles of the present invention are expected to contribute to the industry in terms of energy saving and improvement of work efficiency due to good meltability in a lower temperature range than conventional.

The aspect of the present invention is, for example, as follows.
<1> contains polylactic acid resin as a main component,
The total content of lactide and lactic acid is 0.30% by mass or less,
At least one of the following conditions (1) and (2) is satisfied:
It is a polylactic acid based resin fine particle characterized in that
Condition (1): The molar ratio (L-lactic acid residue / D-lactic acid residue) of L-lactic acid residue and D-lactic acid residue in the polylactic acid-based resin is 1 or more and 7 or less, and the D- The main component of the lactic acid residue is a meso-lactide-derived D-lactic acid residue.
Condition (2): the molar ratio of D-lactic acid residue to L-lactic acid residue (D-lactic acid residue / L-lactic acid residue) in the polylactic acid-based resin is 1 or more and 7 or less, and the L- The main component of a lactic acid residue is an L-lactic acid residue derived from meso lactide.
<2> The polylactic acid-based resin fine particle according to <1>, wherein a total content of lactide and lactic acid is 0.20% by mass or less.
<3> The molar ratio (L-lactic acid residue / D-lactic acid residue) in the condition (1) is 1 or more and 5.67 or less,
The molar ratio (D-lactic acid residue / L-lactic acid residue) in the condition (2) is 1 or more and 5.67 or less,
It is a polylactic acid based resin fine particle according to any one of <1> and <2>.
<4> The polylactic acid-based resin fine particles according to any one of <1> to <3>, wherein the number average molecular weight of the polylactic acid-based resin is 9,000 or more.
<5> 1/2 outflow temperature by a flow tester is 80 ° C or more and 120 ° C or less,
The glass transition temperature is 45.0 ° C. or higher,
It is a polylactic acid-based resin fine particle according to any one of <1> to <4>.

JP-A-8-92518 Patent No. 3395395 gazette

Claims (5)

Containing at least 65% by mass of polylactic acid based resin with respect to polylactic acid based resin particles ,
The total content of lactide and lactic acid is 0.30% by mass or less,
At least one of the following conditions (1) and (2) is satisfied:
Polylactic acid-based resin fine particles characterized by
Condition (1): The molar ratio (L-lactic acid residue / D-lactic acid residue) of L-lactic acid residue and D-lactic acid residue in the polylactic acid-based resin is 1 or more and 7 or less, and the D- 50 mass% or more of lactic acid residues are meso lactide-derived D-lactic acid residues.
Condition (2): the molar ratio of D-lactic acid residue to L-lactic acid residue (D-lactic acid residue / L-lactic acid residue) in the polylactic acid-based resin is 1 or more and 7 or less, and the L- 50 mass% or more of lactic acid residues are L-lactic acid residues derived from meso lactide.   The polylactic acid based resin fine particles according to claim 1, wherein the total content of lactide and lactic acid is 0.20% by mass or less. The molar ratio (L-lactic acid residue / D-lactic acid residue) in the condition (1) is 1 or more and 5.67 or less,
The molar ratio (D-lactic acid residue / L-lactic acid residue) in the condition (2) is 1 or more and 5.67 or less,
The polylactic acid-based resin fine particle according to any one of claims 1 to 2.   The polylactic acid resin fine particles according to any one of claims 1 to 3, wherein the number average molecular weight of the polylactic acid resin is 9,000 or more. 1/2 outflow temperature by the flow tester is 80 ° C or more and 120 ° C or less,
The glass transition temperature is 45.0 ° C. or higher,
The polylactic acid based resin fine particle according to any one of claims 1 to 4.