Marine biodegradable polymer particle swarm and method for producing same

Abstract

The present invention relates to a marine biodegradable polymer particle group comprising a polymer compound in which at least a water-soluble polymer-type multivalent anion having a monovalent anionic substituent derived from an alginic acid product is cross-linked by two or more types of bivalent or higher metal cations, said polymer compound being characterized in that: the polymer compound is a polymer compound containing at least a water-soluble polymer-type multivalent anion having a monovalent anionic substituent derived from an alginic acid product; conditions (1)-(4) are satisfied: (1) the content of the divalent or higher metal cations contained in the particle group is 3-30 mass%, (2) the difference between the maximum value and the minimum value of the atomic radius of the metal elements that are the divalent or higher metal cations is # imgabs0 # or more, and (3) the difference between the maximum value and the minimum value of the atomic radius of the metal elements that are the divalent or higher metal cations is 3-30 mass%. (3) the content of divalent or higher metal cations derived from a metal element having an atomic radius of # imgabs 1 # or more is 25% by mass or more of the total divalent or higher metal cations; and (4) the water absorption of the particle group is less than 300 mL / 100 g.

Description

Technical Field

[0001] The present invention relates to a group of marine biodegradable polymer particles and a method for producing the same. Background Art

[0002] In recent years, environmental pollution (marine pollution) caused by microplastics and adverse effects on ecosystems have become problems, and various studies for reducing the environmental load have been started. Among them, the development and popularization of biodegradable resins have attracted attention. In general, biodegradable resins exhibit high biodegradability in environments where a large amount of microorganisms responsible for degradation exist, such as in soil and sludge, but have the disadvantage of being difficult to degrade in an environment where the microorganism concentration is extremely low, such as in the ocean. Currently, there are few resins that can be biodegraded in the ocean.

[0003] Fine particles are used as a main material in basic industries. Synthetic resins are used as raw materials for the fine particles, but the above-mentioned environmental pollution (marine pollution) and adverse effects on ecosystems have become problems, and research for reducing the generation of microplastics has been started.

[0004] As raw materials for fine particles, natural polymers such as cellulose have attracted attention. However, since cellulose easily absorbs water and has relatively high swelling properties, it is not preferred from the viewpoints of dimensional stability, touch, and moldability. In addition, it has the following disadvantages: it has high degradability on land, such as in soil, but has low solubility and degradability in the ocean.

[0005] Among natural polymers, alginic acid is a polymer derived from seaweed and is degraded relatively quickly in the ocean because it is degraded by marine microorganisms and by enzymes released from seaweeds, shellfish, etc.

[0006] As described in Non-Patent Document 1, since alginic acid can suppress swelling properties by calcium crosslinking, it can be effectively utilized to the maximum extent in cosmetics such as antiperspirants that require moisture absorption and desorption properties, and has high advantages. However, for example, in applications such as base makeup and dot makeup where the softness and touch similar to those of existing plastics are emphasized, problems are caused by a highly crosslinked structure called the egg box structure.

[0007] In Patent Documents 1 and 2, techniques for improving the touch using a hydrophobizing agent are described, and although certain effects have been obtained, there is still room for improvement in softness, smoothness, flexibility, and feel.

[0008] In addition, in the entire industrial materials such as coatings and molded products, in consideration of environmental problems such as marine pollution, there is a demand for more useful raw materials that can replace existing polymer beads, such as touch modifiers and optical properties.

[0009] Prior Art Documents

[0010] Patent Document

[0011] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-125256

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 2021-195321

[0013] Non-Patent Document

[0014] Non-Patent Document 1: Takaya Sato et al., "Development of Calcium Alginate Microspheres and Their Applications in Cosmetics", Fibers and Industry, 1996, Vol. 20, No. 1, pp. 20-26 Summary of the Invention

[0015] Problems to be Solved by the Invention

[0016] In view of the above actual situation, the present invention has been completed, and its object is to provide a practical marine biodegradable polymer particle group that can effectively replace polymer beads for cosmetics, etc. by eliminating the adverse effects of swelling, dimensional stability, touch, optical properties, moldability, etc. caused by natural components, and solve the microplastic problem caused by existing general polymer components

[0017] Means for Solving the Problems

[0018] The inventors of the present invention have repeatedly conducted in-depth research to solve the above problems, and as a result, it has been found that in a polymer particle group obtained by crosslinking with metal cations, by accurately adjusting the type, compounding amount, crosslinking structure, and density of the metal cations used in the crosslinking, the structure can be stabilized, and at the same time, softness, smoothness, flexibility, feel, optical properties such as ultraviolet (UV) scattering, etc. can be imparted to the particles. Furthermore, by using such a polymer particle group in combination with a resin, particularly a biodegradable resin, this material is first degraded once in seawater, and the following effects are obtained: (1) voids are formed in the resin material, the specific surface area of the resin increases, and the proliferation of microorganisms responsible for degradation is promoted; (2) by performing the first degradation, the secondary degradation, i.e., biodegradation by microorganisms, is promoted, and as a result, the biodegradation of the resin material in the ocean can be promoted, thus solving the microplastic problem, and the present invention has been completed

[0019] That is, the present invention provides the following marine biodegradable polymer particle group and its manufacturing method

[0020] 1. A marine biodegradable polymer particle group, which is a marine biodegradable polymer particle group composed of a polymer compound formed by crosslinking a water-soluble polymer type polyvalent anion having a monovalent anionic substituent with two or more divalent or higher metal cations

[0021] The above-mentioned water-soluble polymer type polyvalent anions contain at least water-soluble polymer type polyvalent anions derived from alginic acid and satisfy the following conditions (1) to (4):

[0022] (1) The content of the metal cations with a valence of 2 or more contained in the above particle group is 3 to 30% by mass,

[0023] (2) The difference between the maximum value and the minimum value of the atomic radius of the metal element that is the metal cation with a valence of 2 or more is or more,

[0024] (3) The content of the metal cations with a valence of 2 or more from the metal elements with an atomic radius of or more is 25% by mass or more among all the metal cations with a valence of 2 or more,

[0025] (4) The water absorption of the particle group is less than 300 mL / 100 g.

[0026] 2. The marine biodegradable polymer particle group according to 1, wherein the monovalent anionic substituent is a carboxylate anion.

[0027] 3. The marine biodegradable polymer particle group according to 1 or 2, wherein the water-soluble polymer type polyvalent anions are derived from polysaccharides.

[0028] 4. The marine biodegradable polymer particle group according to any one of 1 to 3, wherein the difference between the maximum value and the minimum value of the atomic radius of the metal element that is the metal cation with a valence of 2 or more is or less.

[0029] 5. The marine biodegradable polymer particle group according to any one of 1 to 4, wherein the atomic radius of the metal element that is the metal cation with a valence of 2 or more is

[0030] 6. The marine biodegradable polymer particle group according to any one of 1 to 5, wherein at least one of the two or more metal cations is a beryllium ion, a magnesium ion, a calcium ion, a strontium ion, a barium ion, a zinc ion or an aluminum ion.

[0031] 7. The marine biodegradable polymer particle group according to 6, wherein at least one of the two or more metal cations is a calcium ion or a strontium ion.

[0032] 8. The marine biodegradable polymer particle group according to any one of 1 to 7, which further satisfies the following condition (5):

[0033] (5) The 10% compressive strength K at a 10% particle size displacement 10 is 1 to 1000 MPa.

[0034] 9. The marine biodegradable polymer particle group according to any one of 1 to 8, further satisfying the following condition (6):

[0035] (6) The melting temperature is 150 °C or higher.

[0036] 10. A method for producing a marine biodegradable polymer particle group, which includes a crosslinking step of crosslinking a water-soluble polymer type polyvalent anion derived from the water-soluble anionic polymer using two or more salt compounds containing a metal cation of divalent or higher in (A) a medium, (B) a medium, or (C) a medium,

[0037] The (A) medium is a medium in which a water-soluble anionic polymer particle group having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is dispersed at a concentration of 5% by mass or more,

[0038] The (B) medium is a medium in which a water-soluble anionic polymer having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is suspended or emulsified in water at a concentration of 5% by mass or more using water and an oily medium,

[0039] The (C) medium is a medium in which a water-soluble anionic polymer having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is hydrophilized or dissolved at a concentration of 5% by mass or more,

[0040] Wherein, the difference between the maximum value and the minimum value of the atomic radius of the metal element that is the metal cation of divalent or higher contained in the salt compound is or more,

[0041] Since the content of the metal cation of divalent or higher from the metal element with an atomic radius of or more becomes 25% by mass or more among all the metal cations of divalent or higher,

[0042] The two or more salt compounds are added in multiple times to carry out the crosslinking reaction.

[0043] 11. The method for producing a marine biodegradable polymer particle group according to 10, wherein, in the above crosslinking step, at least one of the two or more salt compounds is added alone to carry out the crosslinking reaction.

[0044] 12. A UV scattering agent composed of the marine biodegradable polymer particle group according to any one of 1 to 9.

[0045] 13. A marine biodegradable additive composed of the marine biodegradable polymer particle group according to any one of 1 to 9.

[0046] 14. A personal care product, which contains the marine biodegradable additive of 13.

[0047] 15. A cosmetic, which contains the marine biodegradable additive of 13.

[0048] 16. A coating, which contains the marine biodegradable additive of 13.

[0049] 17. An ink, which contains the marine biodegradable additive of 13.

[0050] 18. A resin composition, which contains the marine biodegradable additive of 13.

[0051] 19. A molded article, which contains the marine biodegradable additive described in 13.

[0052] Effects of the Invention

[0053] The marine biodegradable polymer particle group of the present invention uses two or more divalent or higher metal cations in combination. Compared with the egg-box crosslinked structure that stabilizes the structure and crosslinks with a single metal cation, it appropriately destabilizes the structure and adjusts the crosslink density, thereby having moderate softness, smoothness, flexibility, the feel of metal, and optical properties such as UV scattering that have never existed before. In addition, the composition and molded article containing the marine biodegradable polymer particle group of the present invention promote biodegradation in the ocean and can be used for marine pollution countermeasures. Therefore, the marine biodegradable polymer particle group of the present invention is useful as a substitute for existing polymer particles used in various applications. Detailed Embodiments

[0054] [Marine Biodegradable Polymer Particle Group]

[0055] The marine biodegradable polymer particle group of the present invention is composed of a polymer compound formed by crosslinking a water-soluble polymer type polyvalent anion having a monovalent anionic substituent with two or more divalent or higher metal cations. The water-soluble polymer type polyvalent anion contains at least a water-soluble polymer type polyvalent anion derived from alginic acid and satisfies the following conditions (1) to (4).

[0056] (1) The content of the divalent or higher metal cations contained in the particle group is 3 to 30% by mass.

[0057] (2) The difference between the maximum value and the minimum value of the atomic radii of the metal elements that are the divalent or higher metal cations is or more.

[0058] (3) Derived from an atomic radius of The content of metal cations with a valence of 2 or more of the above metal elements is 25% by mass or more among all metal cations with a valence of 2 or more.

[0059] (4) The water absorption of the particle group is less than 300 mL / 100 g.

[0060] Examples of the above-mentioned monovalent anionic substituents include carboxylate anions (-COO - ), sulfonate anions (-SO3 - ), sulfate anions (-O-SO3 - ), phosphate anions (-P(=O)(OH)-O - ), etc. Among these, carboxylate anions, sulfonate anions, and sulfate anions are preferred, and carboxylate anions are particularly preferred from the perspective of environmental considerations.

[0061] As the above-mentioned water-soluble anionic polymer, the raw material is derived from biomass and has a biodegradable structure. Therefore, it is most preferably derived from natural polymers. In particular, as the water-soluble anionic polymer, polysaccharides are preferred.

[0062] As the above-mentioned water-soluble anionic polymer, monovalent salts of polysaccharides, etc. are preferred. Specific examples thereof include monovalent salts of alginic acid such as sodium alginate, potassium alginate, and ammonium alginate; monovalent salts of CMC such as sodium carboxymethyl cellulose (CMC), potassium CMC, and ammonium CMC, and monovalent salts of cellulose derivatives; monovalent salts of processed starches such as sodium octenyl succinate starch and sodium starch glycolate, and monovalent salts of starch derivatives; monovalent salts of hyaluronic acid such as sodium hyaluronate, and monovalent salts of glycosaminoglycan derivatives such as sodium chondroitin sulfate; monovalent salts of chitosan derivatives; monovalent salts of chitin derivatives; monovalent salts of carrageenan such as sodium carrageenan and monovalent salts of carrageenan derivatives; monovalent salts of pectic acid such as sodium polypectate and monovalent salts of pectin derivatives; monovalent salts of natural gums such as gum arabic, xanthan gum, gellan gum, tragacanth gum, and guar gum, and their derivatives; monovalent salts of agar and their derivatives, etc. Among these, as the water-soluble anionic polymer, it is preferred to use only monovalent salts of alginic acid, or a combination of monovalent salts of alginic acid and at least one selected from monovalent salts of CMC, monovalent salts of cellulose derivatives, monovalent salts of octenyl succinate starch and starch derivatives, monovalent salts of hyaluronic acid, and monovalent salts of chondroitin sulfate.

[0063] The above-mentioned water-soluble anionic polymer preferably has a viscosity of 0.01 to 2000 mPa·s, more preferably 0.1 to 1000 mPa·s, and most preferably 1.0 to 500 mPa·s in its 1% by mass or 10% by mass aqueous solution. Considering productivity, it is more preferable that the viscosity of its 10% by mass aqueous solution satisfies the above range. It should be noted that the above viscosity is the measured value at 20 °C using a B-type viscometer with a BL shape.

[0064] The above-mentioned metal cations with a valence of 2 or more are not particularly limited, and examples thereof include calcium ions, strontium ions, beryllium ions, magnesium ions, aluminum ions, zinc ions, iron ions, copper ions, barium ions, platinum ions, gold ions, radium ions, nickel ions, cobalt ions, manganese ions, etc. Among these, beryllium ions, magnesium ions, calcium ions, strontium ions, barium ions, zinc ions, and aluminum ions are preferred. Considering solubility, versatility, and environmental aspects, calcium ions, strontium ions, magnesium ions, aluminum ions, and zinc ions are more preferred.

[0065] The content (total mass) of the metal cations with a valence of 2 or more contained in the above-mentioned marine biodegradable polymer particle group is preferably 3 to 30% by mass, more preferably 4 to 25% by mass, further preferably 5 to 20% by mass, and most preferably 6 to 18% by mass. If the content of the metal cations with a valence of 2 or more is within the above range, the particles will not be significantly deformed by water and can maintain their properties.

[0066] When adjusting the crosslinking density, the size of the atoms of the metal elements given to the above-mentioned metal cations is important. For raw materials using natural components such as polysaccharides, since they have a structure that is easily hydrophilic and easily soluble or swellable, in order to maintain a structure that is insoluble or non-swellable in water and at the same time obtain appropriate softness and feel, it is necessary to balance the adjustment of the crosslinking density by considering the atomic size and the mixing ratio.

[0067] As a result of the research by the present inventors, it was found that: if atoms with a difference in the maximum atomic radius and the minimum atomic radius of at least or more are used together, appropriate softness and feel can be obtained. In addition, it was also confirmed that by using multiple divalent metal cations together, optical properties such as diffusibility are significantly improved.

[0068] The lower limit value of the above-mentioned atomic radius difference is preferably more preferably even more preferably On the other hand, as long as the upper limit value can adjust the crosslinking density, there is no particular limitation. If the crosslinking density becomes too small (few crosslinking points), it will become a structure that is easily soluble or swellable, and it is difficult to adjust. Therefore, as a practical upper limit value, it is preferably more preferably even more preferably It should be noted that in the present invention, the atomic radius is the value described in the Diploma Program (DP) Chemistry Data Book (Japanese version issued in August 2015 (revised in May 2016), which is the Japanese version of the English original Chemistry Data Booklet issued in June 2014).

[0069] In addition, the above metal cations must contain at least one metal cation from a metal element with an atomic radius of or more, and the content of the metal cation is 25% by mass or more among all divalent or higher metal cations. In this case, a marine biodegradable polymer particle group with good softness, tactile properties such as feel, and optical properties such as diffusibility is obtained. The content of the metal cation from a metal element with an atomic radius of or more is preferably 30% by mass or more, more preferably 35% by mass or more, further preferably 40% by mass or more, and most preferably 50% by mass or more. On the other hand, the upper limit of the above content is 100% by mass or less. When including the metal cation from a metal element with an atomic radius less than described later, it is preferably 95% by mass or less, more preferably 90% by mass or less. It should be noted that the content of the metal cation is the value measured by inductively coupled plasma mass spectrometry (ICP-MS).

[0070] When the above metal cations contain two or more metal cations from a metal element with an atomic radius of or more, there is no particular limitation on their content ratio. The content ratio of the metal element with a smaller atomic radius to the metal element with a larger atomic radius is preferably 1:99 to 99:1, more preferably 10:90 to 90:10 in terms of mass ratio.

[0071] Regarding the above metal cations, in addition to the metal element with an atomic radius of or more, they may also contain metal cations from a metal element with an atomic radius less than . The metal element with an atomic radius less than has functionality and can impart functions such as antibacterial property, antifungal property, deodorizing property, and UV removing property according to the purpose. In particular, by including metal cations from a metal element with an atomic radius less than , the UV scattering effect is greatly improved. Therefore, at this time, the marine biodegradable polymer particle group of the present invention is also useful as a UV scattering agent. When including two or more metal cations from a metal element with an atomic radius less than In the case of metal cations of metal elements, there is no particular limitation on their content ratio. The content ratio of a metal element with a small atomic radius to a metal element with a large atomic radius is expressed as a mass ratio, preferably 1:99 to 99:1, more preferably 10:90 to 90:10, and most preferably 20:80 to 80:20.

[0072] In addition, regarding the atomic radius of the metal element that becomes the metal cation with a valence of 2 or more, it is preferably More preferably Further preferably 100 to

[0073]

[0074] From these considerations, regarding metal cations with a valence of 2 or more, from the viewpoints of the balance of crosslinkability, softness, touch improvement such as feel, and optical properties such as diffusibility, it is preferable to contain calcium ions and / or strontium ions as the main components. In particular, it is preferable to contain calcium ions or strontium ions, and at least one metal cation selected from magnesium ions, barium ions, zinc ions, and aluminum ions.

[0075] Regarding the marine biodegradable polymer particle group of the present invention, since the target is a useful application for maintaining the shape during normal use, it is necessary to avoid swelling and excessive water absorption for general water (tap water, ionized water, purified water, etc.). Therefore, the water absorption of the marine biodegradable polymer particle group of the present invention is preferably less than 300 mL / 100 g, more preferably less than 250 mL / 100 g, and further preferably less than 200 mL / 100 g. It should be noted that if the hydrophobization treatment described later is performed, the above water absorption is preferably less than 150 mL / 100 g, more preferably less than 100 mL / 100 g.

[0076] In the applications where the marine biodegradable polymer particle group of the present invention emphasizes softness and touch, it is necessary to have the characteristics of existing polymer particles. As one of the evaluations of its particle characteristics, the compressive strength of one particle at the time of deformation with a particle size displacement of X% can be set as the X% compressive strength to evaluate its characteristics. For example, the 10% compressive strength K when the particle size displacement is 10% 10 is a value obtained by the following formula by measuring the load value (test force) generated by the particle size and the compressive displacement using a micro compression testing machine (MCT-W201, manufactured by Shimadzu Corporation).

[0077] 10% compressive strength K 10 = 2.48 × P 10 / (πd 2 )

[0078] P 10 : Load (N) at 10% deformation of the particle size

[0079] π: Pi (circumference ratio)

[0080] d: Particle size (mm)

[0081] It should be noted that, regarding the compressive strength characteristics during particle size displacement, to generally and quantitatively represent the strength of particles, by using the 10% compressive strength K according to the compression test as in the present invention 10 , the appropriate softness of particles can be quantitatively and uniquely represented.

[0082] In the case of general polymer particles, the 10% compressive strength K 10 is about 0.1 - 5000 MPa. For the marine biodegradable polymer particle group of the present invention, in applications that emphasize softness and touch feeling, its 10% compressive strength K 10 is preferably 1 - 1000 MPa, more preferably 10 - 500 MPa, further preferably 15 - 300 MPa, and most preferably 20 - 200 MPa. It should be noted that in applications that further pursue softness, by appropriately adjusting the type and mixing ratio of metal ions with a valence of 2 or more, the 10% compressive strength K 10 can be adjusted to the range of 20 - 150 MPa, or further adjusted to the range of 20 - 100 MPa.

[0083] The marine biodegradable polymer particle group of the present invention preferably has heat resistance. Specifically, its melting temperature is preferably 150 °C or higher. The above melting temperature is preferably 160 °C or higher, more preferably 180 °C or higher, and further preferably 200 °C or higher. The above melting temperature can be adjusted by adjusting the crosslinking degree. It should be noted that depending on the crosslinking degree, it can also be degraded without melting.

[0084] The marine biodegradable polymer particle group of the present invention may contain 0.01 - 10% by mass of monovalent cations. As the above monovalent cations, monovalent metal cations such as lithium ions, sodium ions, potassium ions, silver ions, etc. can be cited; monovalent organic ions such as ammonium cations, etc. Among these, metal cations are preferred, and sodium ions and potassium ions are more preferred. It is considered that the presence of monovalent cations in the above range reduces the crosslinking density and is one of the main reasons for imparting softness, flexibility, etc.

[0085] Regarding the marine biodegradable polymer particle group of the present invention, from the viewpoint of obtaining good crosslinking degree, the equivalent of the metal cation with a valence of 2 or more is preferably 180 g / equivalent - 1000 g / equivalent. In addition, the equivalent ratio of the metal cation with a valence of 2 or more to the anionic substituent of the above polymer-type polyvalent anion is preferably 0.2:1 - 0.5:1.

[0086] The average particle diameter of the marine biodegradable polymer particle group of the present invention is preferably 5 mm or less, and is preferably in the order of 1 mm or less, 500 μm or less, 100 μm or less, 60 μm or less, 30 μm or less, 15 μm or less, and 10 μm. In addition, the lower limit is preferably 0.1 μm, more preferably 0.5 μm, and further preferably 1.0 μm. It should be noted that in the present invention, the average particle diameter is the volume average diameter (MV) measured by the laser diffraction / scattering method.

[0087] The shape of the marine biodegradable polymer particle group of the present invention is not particularly limited, and may be a spherical shape, a substantially spherical shape, a flat shape, a concave shape, or other physically and chemically controlled shapes, or a physically crushed shape. From the viewpoints of controlling the feel, slidability, and particle size distribution, a physically and chemically controlled shape such as a spherical shape, a substantially spherical shape, an elliptical shape, a flat shape, or a concave shape is preferred. Furthermore, particles formed of curves without sharp angles, such as a substantially spherical shape, an elliptical shape, a flat shape, and a concave shape, are preferred because of their good optical properties.

[0088] In addition, for the marine biodegradable polymer particle group of the present invention, the marine biodegradable polymer particle group is dispersed in a 3% by mass aqueous sodium chloride solution to a concentration of 0.1% by mass, and it is possible to confirm that the shape of the particles changes, accompanied by dissolution and transparency, within 72 hours or 240 hours. In the case where no signs of dissolution or shape change are confirmed in about 240 hours or more, for example, considering environmental pollution (marine pollution), adsorption of chemical substances, and adverse effects on the ecosystem in the ocean, it is not preferred to maintain the particle shape for an overly long period exceeding these.

[0089] The marine biodegradable polymer particle group of the present invention can be hydrophobized using a hydrophobizing agent as needed.

[0090] As the compound for the above hydrophobization treatment (hereinafter also referred to as a hydrophobizing agent), a compound having functions such as making the marine biodegradable polymer particle group hydrophobic and water-repellent can be appropriately selected as long as it does not adversely affect the biodegradability, environmental pollution, and ecosystem of the entire obtained polymer particle group in the ocean.

[0091] The above-mentioned hydrophobizing agent preferably has a salt compound of an anion with 6 or more carbon atoms. The carbon number of the above-mentioned anion is more preferably 10 or more, and further preferably 12 or more. There is no particular limitation on the upper limit of the carbon number of the above-mentioned anion, preferably 30 or less, more preferably 25 or less, and further preferably 20 or less. In addition, the above-mentioned salt compound preferably has a salt compound of a monovalent cation, and more preferably has a salt compound of a monovalent metal cation. In addition, the above-mentioned salt compound preferably dissolves in water at room temperature or below 80°C. If it is such a substance, it has good affinity in seawater and obtains a good biodegradation rate. In addition, as the hydrophilic group, it preferably contains at least one selected from the group consisting of a carboxyl group, an ester bond, a sulfone group, an ether bond, and an amide bond.

[0092] As specific examples of the above-mentioned hydrophobizing agent, carboxylates, amino acid derivative salts, sulfate esters, sulfonates, phosphate esters, lactate salts, etc. can be cited. Regarding the above-mentioned hydrophobizing agent, from an environmental perspective, if it is designed in a manner that sufficiently satisfies the solubility in water and brine and the biodegradability by microorganisms in the environment, the molecular weight is preferably 5000 or less, more preferably 50 to 1000, further preferably 100 to 600, and most preferably 200 to 500.

[0093] As the above-mentioned carboxylate, a salt of a carboxylic acid having 6 to 30 carbon atoms is preferred, a salt of a carboxylic acid having 10 to 25 carbon atoms is more preferred, and a salt of a carboxylic acid having 12 to 20 carbon atoms is further preferred. The above-mentioned carboxylate may be a salt of a monocarboxylic acid or a salt of a polycarboxylic acid.

[0094] As the above-mentioned monocarboxylic acid, caproic acid, heptanoic acid, octanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecenoic acid, lauric acid, myristic acid, pentadecanoic acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid, isostearic acid, oleic acid, vaccenic acid, ricinoleic acid, linoleic acid, linolenic acid, eleostearic acid, keto-stearic acid, arachidic acid, eicosatrienoic acid, arachidonic acid, eicosapentaenoic acid, behenic acid, docosahexaenoic acid, lignoceric acid, nervonic acid, cerotic acid, montanic acid, melissic acid, coconut fatty acid, palm oil fatty acid, etc. can be cited. In addition, they may also be isomers having a branched structure.

[0095] As the above-mentioned polycarboxylic acid, dicarboxylic acids such as suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, icosanedioic acid, etc. can be cited. In addition, they may be isomers having a branched structure of these, or polycarboxylic acids having 3 or more carbon atoms.

[0096] The above-mentioned monocarboxylate salts are preferably monovalent metal salts. Specific examples thereof include octanoates such as potassium octanoate and sodium octanoate; octanoates such as potassium octanoate and sodium octanoate; nonanoates such as potassium nonanoate and sodium nonanoate; decanoates such as potassium decanoate and sodium decanoate; undecylenates such as potassium undecylenate and sodium undecylenate; laurates such as potassium laurate and sodium laurate; myristates such as potassium myristate and sodium myristate; pentadecanoates such as potassium pentadecanoate and sodium pentadecanoate; palmitates such as potassium palmitate and sodium palmitate; heptadecanoates such as potassium heptadecanoate and sodium heptadecanoate; stearates such as potassium stearate and sodium stearate; isostearates such as potassium isostearate and sodium isostearate; oleates such as potassium oleate and sodium oleate; linoleates such as potassium linoleate and sodium linoleate; linolenates such as potassium linolenate and sodium linolenate; arachidonates such as potassium arachidonate and sodium arachidonate; behenates such as potassium behenate and sodium behenate; docosahexaenoates such as sodium docosahexaenoate; coconut fatty acid salts such as potassium coconut fatty acid and sodium coconut fatty acid, etc. Among these, carboxylate salts having 10 to 20 carbon atoms such as laurates, myristates, stearates, and arachidonates are preferred.

[0097] As the above-mentioned polycarboxylate salts, monovalent metal salts are preferred. Specific examples thereof include suberates such as disodium suberate and dipotassium suberate; azelates such as disodium azelate and dipotassium azelate; sebacates such as disodium sebacate and dipotassium sebacate; undecanedioates such as disodium undecanedioate and dipotassium undecanedioate; dodecanedioates such as disodium dodecanedioate and dipotassium dodecanedioate; tridecanedioates such as disodium tridecanedioate and dipotassium tridecanedioate; tetradecanedioates such as disodium tetradecanedioate and dipotassium tetradecanedioate; pentadecanedioates such as disodium pentadecanedioate and dipotassium pentadecanedioate; hexadecanedioates such as disodium hexadecanedioate and dipotassium hexadecanedioate; heptadecanedioates such as disodium heptadecanedioate and dipotassium heptadecanedioate; octadecanedioates such as disodium octadecanedioate and dipotassium octadecanedioate; nonadecanedioates such as disodium nonadecanedioate and dipotassium nonadecanedioate; icosanedioates such as disodium icosanedioate and dipotassium icosanedioate, etc. In addition, isomers having a branched structure of these may be used, and salts of polycarboxylic acids having 3 or more carboxyl groups may also be used. Among these, dicarboxylate salts having 10 to 20 carbon atoms such as sebacates, dodecanedioates, tetradecanedioates, hexadecanedioates, octadecanedioates, and icosanedioates are preferred.

[0098] As the above-mentioned amino acid derivative salts, substances having 6 to 30 carbon atoms are preferred, substances having 10 to 25 carbon atoms are more preferred, and substances having 12 to 20 carbon atoms are further preferred. In addition, the salts of the above-mentioned amino acid derivatives are preferably monovalent salts, and more preferably monovalent metal salts.

[0099] Examples of the amino acid derivatives include sarcosine derivatives such as octanoyl sarcosine, lauroyl sarcosine, myristoyl sarcosine, palmitoyl sarcosine, and cocoyl sarcosine; glutamate derivatives such as octanoyl glutamate, lauroyl glutamate, myristoyl glutamate, palmitoyl glutamate, stearoyl glutamate, cocoyl glutamate, coconut acyl glutamate, acyl glutamate, and dilauroyl glutamate; glycine derivatives such as lauroyl glycine, myristoyl glycine, palmitoyl glycine, palmitoylmethyl glycine, cocoyl glycine, and coconut acyl glycine; alanine derivatives such as lauroyl methylalanine, myristoyl methylalanine, coconut acyl alanine, and cocoyl methylalanine; lysine derivatives such as lauroyl lysine, myristoyl lysine, palmitoyl lysine, stearoyl lysine, oleyl lysine, and acylated lysine; aspartic acid derivatives such as lauroyl aspartic acid, myristoyl aspartic acid, palmitoyl aspartic acid, and stearoyl aspartic acid; taurine derivatives such as lauroyl taurine, lauroyl methyl taurine, myristoyl taurine, myristoyl methyl taurine, palmitoyl taurine, palmitoyl methyl taurine, stearoyl taurine, and stearoyl methyl taurine; and proline derivatives such as lauroyl proline, myristoyl proline, and palmitoyl proline, etc., which are derivatives of amino acids having a hydrocarbon group. N-acyl derivatives of amino acids are particularly preferred.

[0100] Examples of the above-mentioned amino acid derivative salts include sarcosine derivative salts such as potassium octanoyl sarcosinate, sodium octanoyl sarcosinate, potassium lauroyl sarcosinate, sodium lauroyl sarcosinate, potassium myristoyl sarcosinate, sodium myristoyl sarcosinate, potassium palmitoyl sarcosinate, sodium palmitoyl sarcosinate, potassium cocoyl sarcosinate, and sodium cocoyl sarcosinate; glutamate derivative salts such as potassium octanoyl glutamate, sodium octanoyl glutamate, potassium lauroyl glutamate, sodium lauroyl glutamate, potassium myristoyl glutamate, sodium myristoyl glutamate, sodium palmitoyl glutamate, magnesium palmitoyl glutamate, potassium stearoyl glutamate, sodium stearoyl glutamate, potassium cocoyl glutamate, sodium cocoyl glutamate, potassium coconutoyl glutamate, sodium coconutoyl glutamate, potassium acyl glutamate, sodium acyl glutamate, sodium N,N'-dilauroyl-L-glutamate lysinate, and sodium polyglutamate; glycine derivative salts such as potassium lauroyl glycinate, sodium lauroyl glycinate, potassium myristoyl glycinate, sodium myristoyl glycinate, sodium palmitoyl glycinate, sodium palmitoylmethyl glycinate, potassium cocoyl glycinate, sodium cocoyl glycinate, potassium coconutoyl glycinate, and sodium coconutoyl glycinate; alanine derivative salts such as potassium lauroyl methylalaninate, sodium lauroyl methylalaninate, sodium myristoyl methylalaninate, sodium coconutoyl alaninate, and sodium cocoyl methylalaninate; aspartic acid derivative salts such as potassium lauroyl aspartate, sodium lauroyl aspartate, potassium myristoyl aspartate, sodium myristoyl aspartate, potassium palmitoyl aspartate, sodium palmitoyl aspartate, potassium stearoyl aspartate, and sodium stearoyl aspartate; taurine derivative salts such as sodium lauroyl taurinate, potassium lauroyl taurinate, sodium lauroyl methyl taurinate, potassium myristoyl taurinate, sodium myristoyl taurinate, sodium myristoyl methyl taurinate, potassium palmitoyl taurinate, sodium palmitoyl taurinate, potassium palmitoyl methyl taurinate, sodium palmitoyl methyl taurinate, potassium stearoyl taurinate, sodium stearoyl taurinate, and sodium stearoyl methyl taurinate; and proline derivative salts such as sodium lauroyl prolinate, sodium myristoyl prolinate, and sodium palmitoyl prolinate, etc. Amino acid derivative salts having a hydrocarbon group are particularly preferred. N-acyl derivative salts of amino acids are especially preferred.

[0101] Examples of the above-mentioned sulfate salts include alkyl sulfate salts, polyoxyethylene aryl ether sulfate salts, polyoxyethylene alkyl ether sulfate salts, polyoxyalkylene alkyl ether sulfate salts, polyoxyalkylene alkenyl ether sulfate salts, and polyoxyethylene castor oil ether sulfate salts. In addition, the above-mentioned sulfate salts are preferably monovalent salts, and more preferably ammonium salts or monovalent metal salts.

[0102] Specifically, the alkyl sulfate ester salts are preferably those having an alkyl group with 6 to 30 carbon atoms, more preferably those having an alkyl group with 10 to 25 carbon atoms, and still more preferably those having an alkyl group with 12 to 20 carbon atoms. Specific examples thereof include potassium lauryl sulfate, sodium lauryl sulfate, ammonium lauryl sulfate, potassium myristyl sulfate, sodium myristyl sulfate, ammonium myristyl sulfate, sodium cetyl sulfate, ammonium cetyl sulfate, sodium stearyl sulfate, ammonium stearyl sulfate, sodium oleyl sulfate, and ammonium oleyl sulfate.

[0103] The polyoxyethylene aryl ether sulfate salt preferably has an HLB value of 16 or less, and more preferably has an HLB value of 12 or less. Specific examples thereof include polyoxyethylene polycyclic phenyl ether sulfate salts such as sodium polyoxyethylene polycyclic phenyl ether sulfate and ammonium polyoxyethylene polycyclic phenyl ether sulfate; and sodium polyoxyethylene aryl ether sulfate.

[0104] As the polyoxyethylene alkyl ether sulfate salt, those having an HLB value of 16 or less are preferred, and those having an HLB value of 12 or less are more preferred. Specific examples thereof include sodium polyoxyethylene lauryl ether sulfate, ammonium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene myristyl ether sulfate, ammonium polyoxyethylene myristyl ether sulfate, sodium polyoxyethylene cetyl ether sulfate, ammonium polyoxyethylene cetyl ether sulfate, sodium polyoxyethylene stearyl ether sulfate, ammonium polyoxyethylene stearyl ether sulfate, sodium polyoxyethylene oleyl ether sulfate, and ammonium polyoxyethylene oleyl ether sulfate.

[0105] As the polyoxyalkylene alkyl ether sulfate salt, a substance having an HLB value of 16 or less is preferred, and a substance having an HLB value of 12 or less is more preferred. Specific examples thereof include sodium sulfate salts of polyoxyethylene-polyoxypropylene block copolymers, sodium sulfate salts of polyoxyethylene-polyoxybutylene block copolymers, and sodium sulfate salts of alkyl ethers of polyoxyethylene-polyoxypropylene block copolymers. As the above-mentioned polyoxyalkylene alkenyl ether sulfate salt, a substance having an HLB value of 16 or less is preferred, and a substance having an HLB value of 12 or less is more preferred. Specific examples thereof include ammonium sulfate salts of alkenyl ethers of polyoxyethylene-polyoxyalkylene block copolymers. As the above-mentioned polyoxyethylene castor oil ether sulfate and its salt, a substance having an HLB value of 16 or less is preferred, and a substance having an HLB value of 12 or less is more preferred. Specific examples thereof include polyoxyethylene castor oil ether sulfate and polyoxyethylene castor oil ether ammonium sulfate.

[0106] As the above-mentioned sulfonates, sulfonates having 6 to 30 carbon atoms are preferred, sulfonates having 10 to 25 carbon atoms are more preferred, and sulfonates having 12 to 20 carbon atoms are further preferred. In addition, the above-mentioned sulfonates are preferably monovalent salts, and more preferably ammonium salts or monovalent metal salts. Specific examples thereof include alkyl sulfonates such as sodium laurylsulfonate, ammonium laurylsulfonate, sodium myristylsulfonate, ammonium myristylsulfonate, sodium cetylsulfonate, ammonium cetylsulfonate, sodium stearylsulfonate, ammonium stearylsulfonate, sodium oleylsulfonate, and ammonium oleylsulfonate; dodecylbenzenesulfonates such as ammonium dodecylbenzenesulfonate and sodium dodecylbenzenesulfonate; alkylene disulfonates such as sodium alkylene disulfonate; dialkyl succinate sulfonates such as sodium dialkyl succinate sulfonate; monoalkyl succinate sulfonates such as disodium monoalkyl succinate sulfonate; naphthalenesulfonic acid formalin condensate salts such as sodium naphthalenesulfonic acid formalin condensate; olefin sulfonates such as sodium olefin sulfonate and ammonium olefin sulfonate; salts such as potassium lauroyl hydroxyethyl sulfonate, sodium lauroyl hydroxyethyl sulfonate, sodium myristoyl hydroxyethyl sulfonate, sodium palmitoyl hydroxyethyl sulfonate, and sodium stearoyl hydroxyethyl sulfonate; sulfosuccinates such as sodium dihexyl sulfosuccinate, sodium dioctyl sulfosuccinate, ammonium dioctyl sulfosuccinate, sodium didodecyl sulfosuccinate, and sodium diisobutyl sulfosuccinate. Among these, sulfonates having an alkyl group with 12 to 20 carbon atoms are particularly preferred.

[0107] As the above-mentioned phosphate esters, alkyl phosphate esters etc. can be cited. As the above-mentioned alkyl phosphate esters, substances having an alkyl group with 6 to 30 carbon atoms are preferred, substances having an alkyl group with 10 to 25 carbon atoms are more preferred, and substances having an alkyl group with 12 to 20 carbon atoms are further preferred. Specific examples thereof include octyl phosphates such as potassium octyl phosphate; nonyl phosphates such as potassium nonyl phosphate; decyl phosphates such as potassium decyl phosphate; undecyl phosphates such as potassium undecyl phosphate; lauryl phosphates such as potassium lauryl phosphate; myristyl phosphates such as potassium myristyl phosphate; cetyl phosphates such as potassium cetyl phosphate and sodium cetyl phosphate; stearyl phosphates such as potassium stearyl phosphate etc.

[0108] As the above-mentioned lactate salts, substances having 6 to 30 carbon atoms are preferred, substances having 10 to 25 carbon atoms are more preferred, and substances having 12 to 20 carbon atoms are further preferred. Specific examples thereof include sodium stearoyl lactate, potassium stearoyl lactate, sodium isostearoyl lactate, sodium lauroyl lactate, etc.

[0109] Among these, as the hydrophobizing agent, carboxylates, amino acid derivative salts, sulfates, and sulfonates are preferred. Among them, from the environmental perspective, salts having an organic ion as the cation or salts having a metal cation are preferred. As the above-mentioned organic ion, a monovalent organic ion such as an ammonium ion is preferred. In addition, as the above-mentioned metal cation, monovalent metal cations such as lithium ion, potassium ion, sodium ion, and silver ion are preferred. Among them, from the viewpoints of environment, biological safety, versatility, cost, etc., sodium ion, potassium ion, and ammonium ion are preferred, sodium ion and potassium ion are more preferred, and sodium ion is further preferred. By using such a hydrophobizing agent, the anion of the hydrophobizing agent is bonded to a part of the divalent metal cations contained in the above crosslinked polymer through ionic bonds, so that the above crosslinked polymer exhibits hydrophobicity.

[0110] In the above hydrophobizing agent, additives such as carboxylic acids, amino acid derivatives, organosilicon compounds, silicones, fluorine compounds, sulfates, sulfonic acids, phosphates, lactates, oil agents, acrylic compounds, acrylic resins, titanium coupling agents, inorganic compounds, metal oxides, solid lubricants, and surfactants can be added as long as the effects of the present invention are not impaired.

[0111] The above carboxylic acid can be monobasic or polybasic, and specific examples thereof include the above substances. Specific examples of the above amino acid derivatives include the above substances.

[0112] Examples of the above organosilicon compounds include alkylated silanes having at least one alkyl group with 6 to 30 carbon atoms, alkylated silazanes having at least one alkyl group with 6 to 30 carbon atoms, trialkoxysilanes having at least one alkoxy group with 6 to 30 carbon atoms, octyltrialkoxysilane, triethoxysilyl octanoyl silane, 3-methacryloxypropyltrimethoxysilane, etc.

[0113] Examples of the above organosilicon compounds include methylhydrogenpolysiloxane, methylpolysiloxane (polymethylsiloxane), dimethylpolysiloxane (polydimethylsiloxane), triethoxysilylethylpolydimethylsilyloxyethylpolydimethylsiloxane, methylphenylpolysiloxane, triethoxysilylethylpolydimethylsilyloxyethylhexylpolydimethylsiloxane, cyclic organosilicon, crosslinked organosilicon, acrylic-organosilicon graft polymer, organosilicon resin partially crosslinked organopolysiloxane polymer, tetramethyltetrahydrocyclotetrasiloxane, trimethylsilanoxysilicic acid, amino-modified organosilicon, carboxylic acid-modified organosilicon, fluorinated organosilicon, organosilicon gum, acrylic organosilicon, organosilicon resin, triethoxysilylethylpolydimethylsilyloxyethylpolydimethylsiloxane, triethoxysilylethylpolydimethylsilyloxyethylhexylpolydimethylsiloxane, fluorinated organosilicon, etc.

[0114] Examples of the above fluorine compounds include perfluoroalkyl phosphate esters, perfluoroalkyl silanes, perfluoroalkyl alkoxysilanes, esters containing perfluoroalkyl groups, perfluoroalkyl phosphate ester salts, perfluoropolyethers, fluoroorganosilicons, fluorinated organosilicon resins, trimethoxy(3,3,3-trifluoropropyl)silane, tridecafluorooctyltriethoxysilane, and the like.

[0115] Examples of the above sulfate esters include alkyl sulfates, polyoxyethylene aryl ether sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene castor oil ether sulfates, etc. Specifically, as the above alkyl sulfates, sulfates having an alkyl group with 6 to 30 carbon atoms are preferred. Specific examples thereof include lauryl sulfate, myristyl sulfate, cetyl sulfate, stearyl sulfate, oleyl sulfate, etc. As the above polyoxyethylene aryl ether sulfates, substances having an HLB value of 16 or less are preferred, and substances having an HLB value of 12 or less are more preferred. Specific examples thereof include polyoxyethylene polycyclic phenyl ether sulfate, polyoxyethylene aryl ether sulfate, etc. As polyoxyethylene alkyl ether sulfates, substances having an HLB value of 16 or less are preferred, and substances having an HLB value of 12 or less are more preferred.

[0116] As the above sulfonic acids, sulfonic acids having 6 to 30 carbon atoms are preferred. Specific examples thereof include alkyl sulfonic acids such as lauryl sulfonic acid, myristyl sulfonic acid, cetyl sulfonic acid, stearyl sulfonic acid, oleyl sulfonic acid; dodecylbenzenesulfonic acid; alkylene disulfonic acid; dialkyl succinate sulfonic acid; monoalkyl succinate sulfonic acid; naphthalenesulfonic acid formalin condensate; olefin sulfonic acid; hydroxyethyl sulfonic acids such as lauroyl hydroxyethyl sulfonic acid, myristoyl hydroxyethyl sulfonic acid, palmitoyl hydroxyethyl sulfonic acid, stearoyl hydroxyethyl sulfonic acid; sulfosuccinic acid, etc.

[0117] Examples of the above phosphate esters include polyoxyalkylene alkyl ether phosphate esters, alkyl phosphate esters, etc. As the above polyoxyalkylene alkyl ether phosphate esters, substances having an HLB value of 16 or less are preferred, and substances having an HLB value of 12 or less are more preferred. Specific examples thereof include polyoxyethylene(2)stearyl ether phosphate ester, etc.

[0118] As the above alkyl phosphate esters, alkyl phosphate esters having an alkyl group with 6 to 30 carbon atoms are preferred. Specific examples thereof include octyl phosphate ester, nonyl phosphate ester, decyl phosphate ester, undecyl phosphate ester, lauryl phosphate ester, myristyl phosphate ester, cetyl phosphate ester, stearyl phosphate ester, etc.

[0119] As the above lactate esters, lactate esters having 6 to 30 carbon atoms are preferred. Specific examples thereof include lauryl lactate, myristyl lactate, cetyl lactate, oleyl lactate, octyldodecyl lactate, etc.

[0120] Examples of the above-mentioned oil agents include petrolatum, liquid paraffin, squalane, paraffin wax, linseed oil, cottonseed oil, coconut oil, castor oil, egg yolk oil, lanolin fatty acid, dipropylene glycol didecanoate, glyceryl trioctanoate, cetyl 2-ethylhexanoate, isocetyl stearate, stearyl alcohol, cetyl alcohol, oleyl alcohol, beef tallow, beeswax, cetyl wax, wood wax, lanolin, carnauba wax, candelilla wax, etc.

[0121] Examples of the above-mentioned acrylic compounds include alkyl (meth)acrylates, etc. Examples of the above-mentioned acrylic resins include copolymers of (meth)acrylic acid and styrene-based compounds and their salts, copolymers of (meth)acrylic acid and (meth)acrylate-based compounds and their salts, copolymers of (meth)acrylic acid and vinyl ester-based compounds and their salts, copolymers of (meth)acrylic acid and olefin-based compounds and their salts, copolymers of (meth)acrylic acid and conjugated diene-based compounds and their salts, etc.

[0122] Examples of the above-mentioned titanium coupling agents include alkyl titanates, pyrophosphate-type titanates, phosphite-type titanates, amino acid-type titanates, etc.

[0123] Examples of the above-mentioned inorganic compounds include alumina, etc. Examples of the above-mentioned metal oxides include titanium oxide, etc.

[0124] Examples of the above-mentioned solid lubricants include polyolefin waxes (such as polyethylene wax, etc.), paraffin waxes (such as synthetic paraffin wax, natural paraffin wax, etc.), fluororesin-based waxes (such as polytetrafluoroethylene, etc.), fatty acid amide-based compounds (such as stearamide, palmitamide, etc.), metal sulfides (such as molybdenum disulfide, tungsten disulfide, etc.), graphite, fluorinated graphite, boron nitride, polyalkylene glycol, alkali metal sulfates, etc.

[0125] It should be noted that the details of the hydrophobization treatment method will be described later.

[0126] [Method for Producing Marine Biodegradable Polymer Particle Aggregates]

[0127] The method for manufacturing the marine biodegradable polymer particle group of the present invention includes a crosslinking step in which, in medium (A), medium (B), or medium (C), two or more salt compounds containing metal cations with a valence of 2 or more are used as crosslinking agents to crosslink the water-soluble polymer-type polyvalent anions derived from the water-soluble anionic polymer. Medium (A) is a medium in which a water-soluble anionic polymer particle group having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is dispersed at a concentration of 5% by mass or more. Medium (B) is a medium in which a water-soluble anionic polymer having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is suspended or emulsified in water at a concentration of 5% by mass or more using water and an oily medium. Medium (C) is a medium in which a water-soluble anionic polymer having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is hydrophilized or dissolved at a concentration of 5% by mass or more.

[0128] The difference between the maximum and minimum values of the atomic radii of the metal elements that are the metal cations with a valence of 2 or more contained in the above salt compounds is or more, and the content of the metal cations with a valence of 2 or more from the metal elements with an atomic radius of or more is 25% by mass or more among all the metal cations with a valence of 2 or more, and the above two or more salt compounds are added in multiple portions to carry out the crosslinking reaction.

[0129] Hereinafter, the method using medium (A) is referred to as method 1, the method using medium (B) is referred to as method 2, and the method using medium (C) is referred to as method 3.

[0130] Method 1 is a method including the following crosslinking step: in a medium in which a water-soluble anionic polymer particle group having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is dispersed at a concentration of 5% by mass or more, two or more salt compounds containing metal cations with a valence of 2 or more are used as crosslinking agents to crosslink the water-soluble polymer-type polyvalent anions derived from the above water-soluble anionic polymer.

[0131] Regarding the above water-soluble anionic polymer particle group, for example, it can be manufactured by atomizing a solution containing a water-soluble anionic polymer containing at least a monovalent salt of alginic acid.

[0132] As the solvent used in the above solution, water, a hydrophilic organic solvent, or a mixed solvent of water and a hydrophilic organic solvent is preferred. Examples of water include tap water, ion-exchanged water, distilled water, etc. Examples of hydrophilic organic solvents include methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol, methyl cellosolve, ethyl cellosolve, propyl cellosolve, diethylene glycol monobutyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, methyl carbitol, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, formic acid, acetic acid, propionic acid, acetone, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, trioxane, tetrahydrofuran, N-methyl-2-pyrrolidone, dimethylamine, monoethanolamine, pyridine, acetonitrile, etc. These can be used alone or in combination of two or more.

[0133] In the above solvent, a hydrophobic organic solvent can be further added as needed. Examples of hydrophobic organic solvents include higher alcohols such as 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentanol, tert-pentanol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2-ethylbutanol, 1-heptanol, 2-heptanol, 3-heptanol, 2-octanol, 2-ethyl-1-hexanol, benzyl alcohol, cyclohexanol, etc.; ether alcohols such as butyl cellosolve; ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; esters such as ethyl acetate, butyl acetate, ethyl propionate, cellosolve acetate; aliphatic or aromatic hydrocarbons such as pentane, 2-methylbutane, n-hexane, cyclohexane, 2-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane, n-octane, isooctane, 2,2,3-trimethylpentane, decane, nonane, cyclopentane, methylcyclopentane, methylcyclohexane, ethylcyclohexane, p-menthane, dicyclohexane, benzene, toluene, xylene, ethylbenzene; halogenated hydrocarbons such as carbon tetrachloride, trichloroethylene, chlorobenzene, tetrabromoethane; ethers such as diethyl ether, dimethyl ether; acetals such as methylal, diethyl acetal; cyclic, linear or branched silicone oils and their copolymers such as hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), tetradecamethylcycloheptasiloxane (D7), hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, etc., methylpolymethylsiloxane, methylphenylpolysiloxane, diphenylpolysiloxane, diphenylsilanoxyphenylpolymethylsiloxane, trimethylsilanoxyphenylpolydimethylsiloxane, octanoylpolymethylsiloxane, cetylpolydimethylsiloxane; organic compounds containing sulfur and nitrogen such as nitropropylene, nitrobenzene, etc.

[0134] It should be noted that in the present invention, the so-called hydrophilic organic solvent means an organic solvent that maintains a uniform appearance in a mixed solution with the same volume of water, and the so-called hydrophobic organic solvent means an organic solvent that slowly mixes with the same volume of pure water at a temperature of 20 °C under an atmospheric pressure of 1.013×10 5 Pa, and after the flow stops, the mixed liquid cannot maintain a uniform appearance.

[0135] The water-soluble anionic polymer particle group obtained by the above method is dispersed in water, a hydrophilic organic solvent, water, a hydrophilic organic solvent, or a mixed solvent of water and a hydrophilic organic solvent so as to have a concentration of 5% by mass or more. After dispersion, crosslinking treatment is carried out using two or more salt compounds containing metal cations of divalent or higher.

[0136] Method 2 is a method including the following crosslinking step: in a medium in which a water-soluble anionic polymer having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is suspended or emulsified in water at a concentration of 5% by mass or more using water and an oily medium, two or more salt compounds containing metal cations of divalent or higher are used as crosslinking agents to crosslink the water-soluble polymer-type polyvalent anions derived from the above water-soluble anionic polymer.

[0137] Specific examples of the above oily medium include the same oily media as the specific examples of the above hydrophobic organic solvents.

[0138] The method for suspending or emulsifying the water-soluble anionic polymer in water is not particularly limited. For example, there can be mentioned a method of charging the water-soluble anionic polymer, water, an oily medium, a surfactant and other components as needed into a container and suspending or emulsifying them using a stirring device, a homogenizer, etc. In addition, there can be mentioned a method of mixing a solution in which the water-soluble anionic polymer is dissolved in water or a mixed solvent of water and a hydrophilic organic solvent with a hydrophobic organic solvent and suspending or emulsifying them using a stirring device, a homogenizer, etc.

[0139] In Method 2, for the crosslinking treatment, in the above suspension or emulsion (water-in-oil (W / O) emulsion), two or more salt compounds containing metal cations of divalent or higher are used, and the above two or more salt compounds are added in multiple portions for the treatment.

[0140] Method 3 is a method including the following crosslinking step: in a medium in which a water-soluble anionic polymer having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is hydrophilized or dissolved at a concentration of 5% by mass or more, two or more salt compounds containing metal cations of divalent or higher are used as crosslinking agents to crosslink the water-soluble polymer-type polyvalent anions derived from the above water-soluble anionic polymer.

[0141] As a solvent for hydrophilizing or dissolving the water-soluble anionic polymer, water, a hydrophilic organic solvent, or a mixed solvent of water and a hydrophilic organic solvent is preferred. As specific examples of water and the hydrophilic organic solvent, the same solvents as those exemplified in the description of Method 1 can be cited.

[0142] In any of Methods 1 to 3, for the crosslinking treatment, it is preferred to add at least one of two or more salt compounds individually to carry out the crosslinking reaction. Specifically, it is preferred to add them in sequence starting from the salt compound with a metal cation having a small addition amount, or to add together those other than the salt compound with the largest addition amount, and finally add the salt compound with the largest addition amount having a metal cation individually. Thereby, a group of marine biodegradable polymer particles having a metal cation content ratio close to the designed metal cation content ratio is obtained, and the target group of marine biodegradable polymer particles can be obtained stably and with high efficiency.

[0143] For the crosslinking treatment, it can be carried out while heating as needed. The heating temperature is preferably 10 to 100°C, more preferably 15 to 80°C. The treatment time is preferably 0.5 to 24 hours, preferably 1 to 12 hours. By heating, the viscosity of the solvent decreases, so that the metal cation becomes easily impregnated into the interior of the particles.

[0144] It should be noted that for the obtained group of marine biodegradable polymer particles, surface treatment or pulverization treatment can be carried out by known equipment as needed.

[0145] When the hydrophobization treatment is carried out on the group of marine biodegradable polymer particles using a hydrophobizing agent, as the method, a method of carrying out the hydrophobization treatment on the group of marine biodegradable polymer particles obtained by the above method and a method of carrying out the hydrophobization treatment simultaneously with crosslinking in the above Methods 1 to 3 can be cited. As the hydrophobizing agent, the above hydrophobizing agent can be used.

[0146] As a method of carrying out the hydrophobization treatment on the group of marine biodegradable polymer particles, the following method can be cited: dissolving the hydrophobizing agent in a solvent, putting the group of marine biodegradable polymer particles therein, dispersing them, and allowing the hydrophobizing agent to adhere to the surface of the above particles or both the surface and the interior.

[0147] As a method of carrying out the hydrophobization treatment simultaneously with crosslinking in Method 1, the following method can be cited: atomizing and granulating a solution containing at least a monovalent salt of alginic acid and the above hydrophobizing agent, and carrying out the crosslinking treatment by the above method. Thereby, the hydrophobization treatment is also carried out simultaneously.

[0148] As a method of performing hydrophobization simultaneously with crosslinking in Method 2, the following method can be cited: The product obtained by adding the above hydrophobizing agent to the above suspension or emulsion is subjected to crosslinking treatment by the above method. Thus, hydrophobization is also performed simultaneously.

[0149] As a method of performing hydrophobization simultaneously with crosslinking in Method 3, the following method can be cited: The product obtained by adding the above hydrophobizing agent to the above medium is subjected to crosslinking treatment by the above method. Thus, hydrophobization is also performed simultaneously.

[0150] It should be noted that, as a method of performing hydrophobization, specifically, the methods described in paragraphs

[0055] to

[0095] of Japanese Unexamined Patent Application Publication No. 2020-125256, the methods described in paragraphs

[0056] to

[0100] of Japanese Unexamined Patent Application Publication No. 2021-195321, the methods described in paragraphs

[0061] to

[0112] of Japanese Unexamined Patent Application Publication No. 2021-191810, etc. can be referred to.

[0151] [Resin composition]

[0152] By using the marine biodegradable polymer particle group of the present invention in combination with a resin, particularly a biodegradable resin, a resin composition that promotes biodegradation in the ocean can be obtained. In addition, for the purpose of adjusting the physical properties and processability of the resin composition, a variety of resins can also be used in combination. Among them, the so-called biodegradable resin means a resin that degrades due to the action of microorganisms in nature and is finally degraded into inorganic substances such as water and carbon dioxide.

[0153] Examples of the resin that can be combined with the marine biodegradable polymer particle group of the present invention include polyethylene, polyester, polypropylene, polyethylene terephthalate, vinyl chloride, polystyrene, polyurethane, epoxy resin, chlorinated polyethylene resin, chlorinated polypropylene resin, modified nylon resin, phenolic resin, silicone resin, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, styrene-maleic resin, styrene-butadiene resin, butadiene resin, acrylonitrile-butadiene resin, poly(meth)acrylonitrile resin, (meth)acrylamide resin, bio-PET, bio-polyamide, bio-polycarbonate, bio-polyurethane, polyvinyl alcohol, polybutylene adipate / terephthalate, polyethylene glycol terephthalate succinate, bio-polybutylene succinate, polylactic acid blend, starch blend polyester resin, polybutylene terephthalate succinate, polylactic acid, polyhydroxyalkanoic acid, etc. If considering reducing the environmental load, resins with high biodegradability are particularly preferred.

[0154] In addition, examples of the above biodegradable resin include resins derived from petroleum such as polycaprolactone, poly(ε-caprolactone / butylene succinate), polybutylene succinate, polyethylene terephthalate copolymer, poly(ethylene glycol terephthalate / succinate), poly(butylene adipate / terephthalate), poly(tetramethylene adipate / terephthalate), polyethylene succinate, poly(butylene succinate / carbonate), polyvinyl alcohol, polyglycolic acid, glycolic acid / ε-caprolactone copolymer, glycolic acid / trimetylene carbonate copolymer, etc.; resins in which part of the raw materials are derived from biomass such as (polylactic acid / polybutylene succinate)-based block copolymer, (polylactic acid / polycaprolactone) copolymer, (polylactic acid / polyether) copolymer, polylactic acid blend PBAT, lactic acid / glycolic acid copolymer, biopolybutylene succinate, poly(butylene succinate / adipate), starch blend polyester resin, poly(butylene terephthalate succinate), etc.; resins in which 100% of the raw materials are derived from biomass such as polyhydroxyalkanoates such as polyhydroxybutyric acid, polyhydroxyvaleric acid, polyhydroxyoctanoic acid, poly(hydroxybutyrate / hydroxyhexanoate), and polylactic acid; resins derived from natural polymers such as cellulose, cellulose acetate, cellulose ester resin, starch, esterified starch, chitosan, etc. In addition, considering the reduction of environmental load, as the raw materials of the combined resins, those derived from biomass are preferred, and those 100% derived from biomass are most preferred.

[0155] The resin composition of the present invention may contain a solvent. The above solvent may be a solvent that does not dissolve the above marine biodegradable polymer particle group and leaves it as particles, while dissolving the above resin that becomes the matrix, or a solvent that dissolves both the above resin and the marine biodegradable polymer particle group. By appropriately adjusting them, they can also be effectively used as molded articles, coatings, inks, surface treatment agents, etc. produced by film formation such as casting. Examples of preferred solvents include water, hexane, heptane, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dimethyl sulfone, acetone, methyl ethyl ketone, diethyl ketone, acetophenone, dimethyl ether, dipropyl ether, tetrahydrofuran, chloroform, dichloromethane, trichloroethylene, dichloroethylene, dichloroethane, tetrachloroethane, chlorobenzene, methanol, ethanol, n-propanol, isopropanol, butanol, pentanol, methyl ethylene glycol, methyl triglycol, hexyl ethylene glycol, phenyl ethylene glycol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, benzene, toluene, xylene, etc. These can be used alone or in combination of two or more.

[0156] In the case of using a solvent, the total concentration of the resin and the marine biodegradable polymer particle group in the above resin composition is preferably 0.5 to 90% by mass, more preferably 1 to 80% by mass, still more preferably 5 to 60% by mass, and most preferably 10 to 50% by mass. In addition, with respect to the ratio of the marine biodegradable polymer particle group to the above resin, expressed as a mass ratio, it is preferably 99:1 to 10:90, more preferably 97:3 to 40:60, still more preferably 95:5 to 50:50, and most preferably 90:10 to 60:40.

[0157] In addition, the resin composition of the present invention may not contain a solvent. In this case, the above resin can be thermally melted, and the non-melting marine biodegradable polymer particle group can be added thereto and mixed, or both the above resin and the marine biodegradable polymer particle group can be thermally melted and mixed. It should be noted that in the case of thermally melting and mixing the above marine biodegradable polymer particle group with the resin, the above marine biodegradable polymer particle group preferably has a softening point or a melting point suitable for the melting temperature of the resin. As the lower limit value of the above softening point or melting point, it is preferably in the order of 60 °C or higher, 80 °C or higher, 100 °C or higher, 120 °C or higher, and as the upper limit value, it is preferably in the order of 300 °C or lower, 250 °C or lower, 200 °C or lower, 180 °C or lower.

[0158] In the resin composition of the present invention, with respect to the content of the marine biodegradable polymer particle group, from the aspect of obtaining a sufficient degradation promoting effect and desiring to be in a range that does not affect the physical properties of the resin composition, the lower limit value is preferably in the order of 1 part by mass or more, 2 parts by mass or more, 3 parts by mass or more, 5 parts by mass or more with respect to 100 parts by mass of the resin. In addition, the upper limit value of the content of the biodegradability promoter is preferably in the order of 100 parts by mass or less, 80 parts by mass or less, 50 parts by mass or less, 30 parts by mass or less. In particular, when the marine biodegradable polymer particle group exists in a particulate state, the lower limit value of its content is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and the upper limit value of its content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less.

[0159] Regarding the resin composition of the present invention, if necessary, it may contain additives such as antioxidants, mold release agents, release agents, surface modifiers, hydrophobizing agents, water repellent agents, hydrophilic agents, dyes, colorants, heat stabilizers, light stabilizers, weather resistance improvers, antistatic agents, antifogging agents, lubricants, anti-blocking agents, hardening agents, softening agents, compatibilizers, flame retardants, fluidity improvers, plasticizers, dispersants, antibacterial agents, fillers, metal deactivators, etc. The content of these additives is not particularly limited as long as the effects of the present invention are not impaired, and it is preferably about 0.1 to 50 parts by mass with respect to 100 parts by mass of the resin.

[0160] When the above resin composition contains a solvent, for example, it can be prepared by adding the resin, the marine biodegradable polymer particle group, and the above additives used as needed to the solvent simultaneously or in any order and mixing them. Additionally, when the above resin composition does not contain a solvent, for example, the above resin can be melted, and the marine biodegradable polymer particle group and the above additives used as needed can be added and mixed therein simultaneously or in any order, or the above resin and the marine biodegradable polymer particle group can be heated and melted together for mixing, and the above additives can be added and mixed as needed.

[0161] [Molded article]

[0162] By molding using the above resin composition, a molded article in which the marine biodegradable polymer particle group is dispersed or dissolved in the above resin can be obtained. When the above resin composition contains a solvent, the resin composition can be directly used for molding. When the above resin composition does not contain a solvent, the resin or the resin and the marine biodegradable polymer particle group in the resin composition can be melted with heat and then molded.

[0163] As the shape of the above molded article, for example, a film shape, a fibrous shape, a plate shape, a foamed molded article shape, other shapes suitable for the use, etc. can be cited. As the molding method, there is no particular limitation, and various conventionally known molding methods can be used. As specific examples thereof, blow molding, injection molding, extrusion molding, compression molding, melt extrusion molding method, solution casting molding method, calendering molding method, etc. can be cited.

[0164] [Surface modifier]

[0165] Regarding the marine biodegradable polymer particle group of the present invention, by utilizing the property of being soluble in salt water, it can also be used as a pore former and a surface modifier for manufacturing a porous body. For example, by immersing a molded article obtained from a resin composition containing the above marine biodegradable polymer particle group in an aqueous solution of a monovalent metal salt such as sodium chloride or potassium chloride, only the surface layer part can be surface-modified. By further continuously immersing, the marine biodegradable polymer particle group dissolves, and a porous body can be manufactured. Applying these characteristics, it can be developed into surface treatment agents, coatings, inks, etc.

[0166] [Uses of marine biodegradable polymer particle group]

[0167] By dispersing the marine biodegradable polymer particle group of the present invention in water, a hydrophilic organic solvent, a hydrophobic organic solvent, or a mixed solvent thereof, it can be used as a dispersion liquid.

[0168] The marine biodegradable polymer particle group of the present invention can be used as an additive in molded articles such as liquids, coatings, films, sheets, and papers. For example, it can be widely used in light scattering agents, optical filter materials, colorants, cosmetics, absorbents, adsorbents, inks, adhesives, electromagnetic wave shielding materials, fluorescence sensors, biological markers, recording materials, recording elements, polarization materials, drug carriers for drug delivery systems (DDS), biosensors, DNA chips, test drugs, fired porous molded articles, anti-adhesives, etc.

[0169] Furthermore, with respect to shielding light or UV incident on indoor areas such as through window glass products, curtains, wall materials, etc., it is not only possible to prevent sunburn and adverse effects on the human body, but also to prevent deterioration of indoor and in-vehicle decorations, etc., and thus becomes useful in such aspects.

[0170] The marine biodegradable polymer particle group of the present invention is suitable as an additive for personal care products and cosmetics. At this time, the marine biodegradable polymer particles of the present invention are preferably added in applications such as scrubbing agents, extenders, thickeners, tactile modifiers, film-forming agents, etc.

[0171] The marine biodegradable polymer particle group of the present invention is mainly composed of natural polymers, and it becomes possible to expand in applications that use a large amount of liquid components such as liquid systems while improving lightness, touch, flow characteristics, solution dispersibility, etc. In addition, in the case of having a concave shape, due to its unique shape, it has an adhesion different from that of general spherical shapes, and has the effect of improving the fixing force and the holding force after coating of molded articles such as foundation while obtaining an improvement in light scattering properties, etc. Furthermore, due to its optical properties, it makes the skin look bright and can improve the coverage by a blurring effect. In addition, due to the shape and the unique slipperiness and optical properties from containing multiple metal cations, it has excellent spreadability on the skin, and further fills the grooves of the texture in detail, thereby making wrinkles and pores less obvious, or freely controlling the fluidity, light diffusion, etc. of the whole product. As a preferred addition amount, it is 0.1 to 50% by mass, preferably 0.5 to 30% by mass, relative to the product formulation amount. It can be appropriately adjusted according to uses / purposes such as UV scattering effect, blurring effect, etc., light scattering properties, fluidity, moldability, adhesion improvement, finishing feeling, etc. It should be noted that according to the research of the present inventors, as an additive for cosmetics, it is particularly preferably contained in an amount of 1 to 20% by mass. It should be noted that it can be used in combination by appropriately adjusting with commercially available particles.

[0172] Specifically, as cosmetics with high efficacy, specifically, they can be skin care products, hair products, antiperspirant products, beauty products, anti-UV products, fragrance products, etc. For example, basic cosmetics such as lotions, creams, toners, colored toners, sunscreen agents, makeup bases, sunscreen agents, aftershave lotions, pre-shave lotions, mask materials, makeup removers, facial cleansers, acne countermeasure cosmetics, essential oils, etc., color cosmetics such as foundations, face powders, mascaras, eyeshadows, eyeliners, eyebrow pencils, blushes, nail polishes, lip balms, lipsticks, etc., hair care products such as shampoos, mouthwashes, hair conditioners, hair dyes, hair conditioners, hair styling agents, body powders, hair growth agents, deodorants, hair removal agents, soaps, body washes, bath salts, hand soaps, perfumes, etc. In addition, there is no particular limitation on the form of the product, and it can be liquid, lotion, paste, solid, paste, gel, powder, multi-layer, mousse, spray, etc. Useful effects can be expected as additives to these cosmetics.

[0173] The marine biodegradable polymer particle group of the present invention can be used as an additive for printing inks used in screen printing, offset printing, flexographic printing, gravure printing, tampo printing, coaters, inkjet, etc., an additive for pen inks used in markers, ballpoint pens, fountain pens, fountain pens, felt-tip pens, etc., and an additive for stationery such as crayons, painting tools, erasers.

[0174] The marine biodegradable polymer particle group of the present invention is suitable as an additive for paints used in brush coating, spraying, electrostatic coating, electro-deposition coating, flow coating, roll coating, dip coating, etc. For example, it is suitable for use as an additive for paints used in transportation equipment such as cars, trams, helicopters, ships, bicycles, snowmobiles, cable cars, elevators, forklifts, motorcycles, etc., building components such as window frames, shutters, water storage tanks, doors, balconies, exterior wall panels for buildings, roofing materials, stairs, skylights, concrete walls, etc., exterior or interior decorations of buildings, guardrails, pedestrian bridges, sound insulation walls, signs, highway sidewalls, railway viaducts, bridges, etc., equipment components such as tanks, pipes, towers, chimneys, etc., agricultural equipment such as plastic greenhouses, greenhouses, silos, agricultural sheets, etc., communication equipment such as utility poles, transmission towers, parabolic antennas, etc., electrical equipment such as electrical distribution boxes, lighting fixtures, outdoor air conditioners, washing machines, refrigerators, microwave ovens, etc. and their covers, monuments, tombstones, paving materials, windproof sheets, waterproof sheets, building curing sheets, etc.

[0175] As the form of the paint, in addition to solvent-based paints, it is also water-dispersible paints, non-water-dispersible paints, powder paints, electro-deposition paints, etc., which can be appropriately selected as needed.

[0176] Examples

[0177] Hereinafter, production examples, examples, and comparative examples are listed to illustrate the present invention more specifically, but the present invention is not limited to the following examples. It should be noted that in the following examples and comparative examples, the content and content ratio of metal cations were measured by ICP-MS (ICPE-9820 manufactured by Shimadzu Corporation). The particle size distribution and volume average particle diameter (MV) were measured using MICROTRACK MT3000 (manufactured by Nikkiso Co., Ltd.). In addition, the sodium alginate and potassium alginate used in the following production examples and examples are as described below.

[0178] · Sodium alginate: manufactured by Kimica Co., Ltd., trade name Kimica Algine ULV-L3 (viscosity when prepared as a 10% by mass aqueous solution is 40 mPa·s)

[0179] · Potassium alginate: manufactured by Kimica Co., Ltd., trade name Kimica Algine K-ULV-L3 (viscosity when prepared as a 10% by mass aqueous solution is 40 mPa·s)

[0180] [1] Production of marine biodegradable polymer particle groups

[0181] [Production Example 1] Production of pre-crosslinked polymer particle group A1

[0182] The following components were placed in a 5000 mL heatable container and dispersed using a stirrer.

[0183] Sodium alginate 400.0 g

[0184] Ion-exchanged water 4000.0 g

[0185] Then, it was heated to 60°C and sodium alginate was dissolved over 2 hours to prepare a 9.0% by mass aqueous solution. Next, while maintaining the state where the solid components were dissolved, the obtained aqueous solution was spray-dried (hot air temperature 200°C) using a spray dryer to obtain pre-crosslinked polymer particle group A1. The obtained particle group was observed by SEM to confirm the shape, and the result was a particle group of substantially spherical particles with depressions, and a monodisperse particle group with an MV of 6 μm in the particle size distribution.

[0186] [Production Example 2] Production of pre-crosslinked polymer particle group A2

[0187] The following components were placed in a 5000 mL heatable container and dispersed using a stirrer.

[0188] Sodium alginate 256.0 g

[0189] Sodium CMC 64.0 g

[0190] Ion-exchanged water 4260.0 g

[0191] Then, it is heated to 60 °C and sodium alginate and sodium CMC are dissolved for 2 hours to prepare a 7.0 mass% aqueous solution. Next, while maintaining the state where the solid components are dissolved, the obtained aqueous solution is spray-dried using a spray dryer (hot air temperature: 200 °C) to obtain a pre-crosslinked polymer particle group A2. The obtained particle group A2 is observed by SEM to confirm the shape. As a result, the particles are substantially spherical with depressions, and it is a monodisperse particle group with an MV of 5 μm in the particle size distribution.

[0192] [Production Example 3] Production of pre-crosslinked polymer particle group A3

[0193] The following components are placed in a 2000 mL heatable container and dispersed using a stirrer.

[0194] Sodium alginate 57.0 g

[0195] Sodium hyaluronate 3.0 g

[0196] Ion-exchanged water 798.0 g

[0197] Then, it is heated to 60 °C and sodium alginate and sodium hyaluronate are dissolved for 2 hours to prepare a 7.0 mass% aqueous solution. Next, while maintaining the state where the solid components are dissolved, the obtained aqueous solution is spray-dried using a spray dryer (hot air temperature: 200 °C) to obtain a pre-crosslinked polymer particle group A3. The obtained particle group is observed by SEM to confirm the shape. As a result, the particles are spherical, and it is a monodisperse particle group with an MV of 30 μm in the particle size distribution.

[0198] [Production Example 4] Production of pre-crosslinked polymer particle group A4

[0199] The following components are placed in a 10000 mL heatable container and dispersed using a stirrer.

[0200] Potassium alginate 304.0 g

[0201] Sodium palmitate 16.0 g

[0202] Ion-exchanged water 4250.0 g

[0203] Then, it is heated to 60 °C and potassium alginate and sodium palmitate are dissolved for 2 hours to prepare a 7.0 mass% aqueous solution. Next, while maintaining the state where the solid components are dissolved, the obtained aqueous solution is spray-dried using a spray dryer (hot air temperature: 200 °C) to obtain a pre-crosslinked polymer particle group A4. The obtained particle group is observed by SEM to confirm the shape. As a result, the particles are substantially spherical with depressions, and it is a monodisperse particle group with an MV of 15 μm in the particle size distribution.

[0204] [Example 1-1] Preparation of Marine Biodegradable Polymer Particle Group AC-1

[0205] Charge the following components into a 300 mL flask, and use a stirrer to prepare a 30% by mass alcoholic dispersion of pre-crosslinked polymer particle group A1.

[0206] Pre-crosslinked polymer particle group A1 30.0 g

[0207] Isopropyl alcohol (IPA) 70.0 g

[0208] Next, drop 9.4 g of a 40% by mass magnesium chloride aqueous solution into the above-mentioned stirred alcoholic dispersion. After the dropping is completed, continue stirring for 1 hour to perform the first crosslinking treatment. After the first crosslinking treatment, slowly add 18.8 g of a 40% by mass calcium chloride aqueous solution to the above-mentioned alcoholic dispersion, stir for 15 minutes, and then drop 50.0 g of purified water, stir for 2 hours to perform the second crosslinking treatment. After the stirring is completed, use ion-exchanged water to repeatedly filter and wash, and powderize the final dispersion by a freeze dryer to obtain the target marine biodegradable polymer particle group AC-1.

[0209] Observe the marine biodegradable polymer particle group AC-1 by SEM to confirm the shape. The result is that the particle size is approximately the same as that before the crosslinking treatment. In addition, confirm the particle size distribution by measuring the particle size distribution. The result shows the same distribution as that before the crosslinking treatment. Therefore, it is confirmed that there is no aggregation and it is a monodisperse particle group. It should be noted that the contents of magnesium and calcium obtained by ICP-MS are 8.2% by mass, and the content ratio is Mg:Ca = 1:1.9.

[0210] [Example 1-2] Preparation of Marine Biodegradable Polymer Particle Group AC-2

[0211] Change 9.4 g of a 40% by mass magnesium chloride aqueous solution to 9.4 g of a mixed aqueous solution of 40% by mass magnesium chloride and strontium chloride (the mass ratio of magnesium chloride to strontium chloride is 2:3). Except for this, use the same method as in Example 1-1 to obtain the target marine biodegradable polymer particle group AC-2.

[0212] Observe the marine biodegradable polymer particle group AC-2 by SEM to confirm the shape. The result is that the particle size is approximately the same as that before the crosslinking treatment. In addition, confirm the particle size distribution by measuring the particle size distribution. The result shows the same distribution as that before the crosslinking treatment. Therefore, it is confirmed that there is no aggregation and it is a monodisperse particle group. It should be noted that the contents of magnesium, strontium and calcium obtained by ICP-MS are 11.4% by mass, and the content ratio is Mg:Sr:Ca = 1:3:5.7.

[0213] [Example 1-3] Preparation of Marine Biodegradable Polymer Particle Group AC-3

[0214] 9.4 g of a 40% by mass aqueous magnesium chloride solution was changed to 9.4 g of a 40% by mass aqueous zinc chloride solution. Except for this, the target marine biodegradable polymer particle group AC-3 was obtained in the same manner as in Example 1-1.

[0215] The marine biodegradable polymer particle group AC-3 was observed by SEM to confirm the shape, and the result was that the particle size was approximately the same as that before the crosslinking treatment. In addition, the particle size distribution was confirmed by measuring the particle size distribution, and the result showed the same distribution as before the crosslinking treatment. Therefore, it was confirmed that the particle group was non-aggregated and monodisperse. It should be noted that the contents of zinc and calcium obtained by ICP-MS were 12.2% by mass, and the content ratio was Zn:Ca = 1:1.3.

[0216] [Example 1-4] Preparation of marine biodegradable polymer particle group AC-4

[0217] The following components were placed in a 300 mL flask, and a 30% by mass alcohol dispersion of the pre-crosslinked polymer particle group A1 was prepared using a stirrer.

[0218] Pre-crosslinked polymer particle group A1 30.0 g

[0219] IPA 70.0 g

[0220] Next, 7.5 g of a 40% by mass aqueous magnesium chloride solution was dropped into the above-mentioned stirred alcohol dispersion. After the dropping was completed, stirring was continued for 1 hour to perform the first crosslinking treatment. After the first crosslinking treatment, 22.5 g of a 40% by mass aqueous strontium chloride solution was slowly added to the above-mentioned alcohol dispersion, and stirring was carried out for 15 minutes. Then, 50.0 g of purified water was dropped in, and stirring was carried out for 2 hours to perform the second crosslinking treatment. After the stirring was completed, filtration and washing were repeated using ion-exchanged water, and the final dispersion was powdered by a freeze dryer to obtain the target marine biodegradable polymer particle group AC-4.

[0221] The marine biodegradable polymer particle group AC-4 was observed by SEM to confirm the shape, and the result was that the particle size was approximately the same as that before the crosslinking treatment. In addition, the particle size distribution was confirmed by measuring the particle size distribution, and the result showed the same distribution as before the crosslinking treatment. Therefore, it was confirmed that the particle group was non-aggregated and monodisperse. It should be noted that the contents of magnesium and strontium obtained by ICP-MS were 15.8% by mass, and the content ratio was Mg:Sr = 1:5.5.

[0222] [Example 1-5] Preparation of marine biodegradable polymer particle group AC-5

[0223] 7.5 g of a 40% by mass aqueous magnesium chloride solution was changed to 7.5 g of a 40% by mass aqueous zinc chloride solution, and otherwise, the target marine biodegradable polymer particle group AC-5 was obtained in the same manner as in Examples 1-4.

[0224] The marine biodegradable polymer particle group AC-5 was observed by SEM to confirm the shape, and the result was that the particle size was substantially the same as before the crosslinking treatment. In addition, the particle size distribution was confirmed by measuring the particle size distribution, and the result showed the same distribution as before the crosslinking treatment. Therefore, it was confirmed that the particle group was non-aggregated and monodisperse. It should be noted that the contents of zinc and strontium obtained by ICP-MS were 20.5% by mass, and the content ratio was Zn:Sr = 1:3.5.

[0225] [Examples 1-6] Production of marine biodegradable polymer particle group AC-6

[0226] The following components were placed in a 300 mL flask, and a 30% by mass alcoholic dispersion of the pre-crosslinked polymer particle group A1 was prepared using a stirrer.

[0227] Pre-crosslinked polymer particle group A1 30.0 g

[0228] IPA 70.0 g

[0229] Next, 5.65 g of a 40% by mass aqueous magnesium chloride solution was dropped into the above-mentioned stirred alcoholic dispersion. After the dropping was completed, stirring was continued for 1 hour, and one crosslinking treatment was carried out. After the first crosslinking treatment, 5.65 g of a 40% by mass aqueous strontium chloride solution was dropped into the above-mentioned stirred alcoholic dispersion. After the dropping was completed, stirring was continued for 1 hour, and the second crosslinking treatment was carried out. After the second crosslinking treatment, 16.9 g of a 40% by mass aqueous calcium chloride solution was slowly added to the above-mentioned alcoholic dispersion, and stirred for 15 minutes. Then, 50.0 g of purified water was dropped in, and stirred for 2 hours, and the third crosslinking treatment was carried out. After the stirring was completed, it was repeatedly filtered and washed with ion-exchanged water, and the final dispersion was pulverized by a freeze dryer to obtain the target marine biodegradable polymer particle group AC-6.

[0230] The marine biodegradable polymer particle group AC-6 was observed by SEM to confirm the shape, and the result was that the particle size was substantially the same as before the crosslinking treatment. In addition, the particle size distribution was confirmed by measuring the particle size distribution, and the result showed the same distribution as before the crosslinking treatment. Therefore, it was confirmed that the particle group was non-aggregated and monodisperse. It should be noted that the contents of magnesium, calcium and strontium obtained by ICP-MS were 11.0% by mass, and the content ratio was Mg:Ca:Sr = 1:3.2:2.2.

[0231] [Examples 1-7] Production of marine biodegradable polymer particle group AC-7

[0232] In a 300 mL flask, the following components were charged, and a 30 mass% alcoholic dispersion of prepolymer particles A1 before crosslinking was prepared using a stirrer.

[0233] Prepolymer particles A1 before crosslinking 30.0 g

[0234] IPA 70.0 g

[0235] Next, 5.25 g of a 40 mass% magnesium chloride aqueous solution was dropped into the above-mentioned stirred alcoholic dispersion. After the dropping was completed, stirring was continued for 1 hour to perform the first crosslinking treatment. After the first crosslinking treatment, 3.00 g of a 30 mass% aluminum chloride aqueous solution was dropped into the above-mentioned stirred alcoholic dispersion. After the dropping was completed, stirring was continued for 1 hour to perform the second crosslinking treatment. After the second crosslinking treatment, 13.15 g of a 40 mass% calcium chloride aqueous solution was slowly added to the above-mentioned alcoholic dispersion, and stirring was carried out for 15 minutes. Further, 50.0 g of purified water was dropped, and stirring was carried out for 2 hours to perform the third crosslinking treatment. After the stirring was completed, filtration and washing were repeated using ion-exchanged water, and the final dispersion was pulverized by a freeze dryer to obtain the target marine biodegradable polymer particle group AC-7.

[0236] The marine biodegradable polymer particle group AC-7 was observed by SEM to confirm the shape, and the result was that the particle size was substantially the same as that before the crosslinking treatment. In addition, the particle size distribution was confirmed by measuring the particle size distribution, and the result showed the same distribution as that before the crosslinking treatment. Therefore, it was confirmed that the particles were non-aggregated and monodispersed. It should be noted that the contents of magnesium, aluminum, and calcium obtained by ICP-MS were 8.4 mass%, and the content ratio was Mg:Al:Ca = 2.9:1:11.4.

[0237] [Example 1-8] Production of marine biodegradable polymer particle group AC-8

[0238] In a 300 mL flask, the following components were charged, and a 30 mass% alcoholic dispersion of prepolymer particles A2 before crosslinking was prepared using a stirrer.

[0239] Prepolymer particles A2 before crosslinking 30.0 g

[0240] IPA 70.0 g

[0241] Next, 9.4 g of a 40% by mass aqueous magnesium chloride solution was dropped into the above-mentioned stirred alcohol dispersion. After the dropping was completed, stirring was continued for 1 hour to perform a crosslinking treatment once. After the first crosslinking treatment, 18.8 g of a 40% by mass aqueous calcium chloride solution was slowly added to the above-mentioned alcohol dispersion, and the mixture was stirred for 15 minutes. Then, 50.0 g of purified water was dropped in, and stirring was carried out for 2 hours to perform a crosslinking treatment twice. After the stirring was completed, filtration and washing were repeated using ion-exchanged water, and the final dispersion was pulverized by a freeze dryer to obtain the target marine biodegradable polymer particle group AC-8.

[0242] The marine biodegradable polymer particle group AC-8 was observed by SEM to confirm the shape, and the result was that the particle size was approximately the same as that before the crosslinking treatment. In addition, the particle size distribution was confirmed by measuring the particle size distribution, and the result showed the same distribution as before the crosslinking treatment. Therefore, it was confirmed that the particle group was non-aggregated and monodisperse. It should be noted that the contents of magnesium and calcium obtained by ICP-MS were 8.0% by mass, and the content ratio was Mg:Ca = 1:1.8.

[0243] [Example 1-9] Preparation of Marine Biodegradable Polymer Particle Group AC-9

[0244] The following components were placed in a 300 mL flask, and a 30% by mass alcohol dispersion of the pre-crosslinked polymer particle group A3 was prepared using a stirrer.

[0245] Pre-crosslinked polymer particle group A3 30.0 g

[0246] IPA 70.0 g

[0247] Next, 7.5 g of a 40% by mass aqueous magnesium chloride solution was dropped into the above-mentioned stirred alcohol dispersion. After the dropping was completed, stirring was continued for 1 hour to perform a crosslinking treatment once. After the first crosslinking treatment, 20.65 g of a 40% by mass aqueous strontium chloride solution was slowly added to the above-mentioned alcohol dispersion, and the mixture was stirred for 15 minutes. Then, 50.0 g of purified water was dropped in, and stirring was carried out for 2 hours to perform a crosslinking treatment twice. After the stirring was completed, filtration and washing were repeated using ion-exchanged water, and the final dispersion was pulverized by a freeze dryer to obtain the target marine biodegradable polymer particle group AC-9.

[0248] The marine biodegradable polymer particle group AC-9 was observed by SEM to confirm the shape, and the result was that the particle size was approximately the same as that before the crosslinking treatment. In addition, the particle size distribution was confirmed by measuring the particle size distribution, and the result showed the same distribution as before the crosslinking treatment. Therefore, it was confirmed that the particle group was non-aggregated and monodisperse. It should be noted that the contents of magnesium and strontium obtained by ICP-MS were 15.5% by mass, and the content ratio was Mg:Sr = 1:5.8.

[0249] [Example 1-10] Production of Marine Biodegradable Polymer Particle Group AC-10

[0250] In a 300 mL flask, the following components were charged, and a 30 mass% alcoholic dispersion of pre-crosslinked polymer particle group A4 was prepared using a stirrer.

[0251] Pre-crosslinked polymer particle group A4 30.0 g

[0252] IPA 70.0 g

[0253] Next, 7.5 g of a 40 mass% zinc chloride aqueous solution was dropped into the above-mentioned stirred alcoholic dispersion. After the dropping was completed, stirring was continued for 1 hour to perform a crosslinking treatment once. After the first crosslinking treatment, 20.65 g of a 40 mass% strontium chloride aqueous solution was slowly added to the above-mentioned alcoholic dispersion, and stirring was carried out for 15 minutes. Then, 50.0 g of purified water was dropped in, and stirring was carried out for 2 hours to perform a crosslinking treatment twice. After the stirring was completed, ion-exchanged water was used for repeated filtration and washing, and the final dispersion was powdered by a freeze dryer to obtain the target marine biodegradable polymer particle group AC-10.

[0254] The marine biodegradable polymer particle group AC-10 was observed by SEM to confirm the shape. As a result, the particle size was approximately the same as that before the crosslinking treatment. In addition, the particle size distribution was confirmed by measuring the particle size distribution. As a result, the distribution was the same as that before the crosslinking treatment. Therefore, it was confirmed that the particle group was non-aggregated and monodisperse. It should be noted that the contents of zinc and strontium obtained by ICP-MS were 18.7 mass%, and the content ratio was Zn:Sr = 1:3.3.

[0255] [Example 1-11] Production of Marine Biodegradable Polymer Particle Group AC-11 In a 5000 mL heatable container, the following components were charged, and stirring was carried out for 5 minutes using a homogenizer (T25 manufactured by IKA) to emulsify them.

[0256]

[0257] 62.5 g of a 40 mass% magnesium chloride aqueous solution was dropped into it. After the dropping was completed, stirring was continued for 1 hour to perform a crosslinking treatment once. Next, 125.0 g of a 40 mass% calcium chloride aqueous solution was dropped in. After the dropping was completed, stirring was carried out at 50 °C for 2 hours to perform a crosslinking treatment twice. After cooling, centrifugal washing was repeatedly carried out with ethanol and ion-exchanged water, and the final dispersion was powdered by a freeze dryer to obtain the target marine biodegradable polymer particle group AC-11.

[0258] SEM observation of the marine biodegradable polymer particles AC-11 revealed spherical particles with a monodisperse particle size distribution of 10 μm. Furthermore, ICP-MS analysis revealed magnesium and calcium contents of 8.0% by mass, with a ratio of Mg:Ca = 1:1.5.

[0259] [Example 1-12] Production of Marine Biodegradable Polymer Particles AC-12

[0260] The following components were placed in a 3000 mL heatable container and completely dissolved using a stirrer at 60°C.

[0261] Sodium alginate 190.0g

[0262] Sodium N-myristoyl sarcosinate 10.0g

[0263] Ion exchange water 1000.0g

[0264] Therein, 62.5g of 40% by mass magnesium chloride aqueous solution was added dropwise under high-speed stirring. After the addition was completed, stirring was continued for 1 hour, and a cross-linking treatment was implemented. Secondly, 125.0g of 40% by mass strontium chloride aqueous solution was added dropwise. After the addition was completed, stirring was carried out for 2 hours at 50°C, and a cross-linking treatment was implemented twice to completely separate it as particles. After stirring was completed, ion exchange water was used to filter and wash repeatedly to dry the particles. By using a pulverizer (WB-1 manufactured by Osaka Chemical (Strain)), the particles obtained were pulverized to obtain the target marine biodegradable polymer particle group AC-12.

[0265] SEM observation of the AC-12 marine biodegradable polymer particles revealed irregularly shaped particles with a monodisperse particle size distribution of 8 μm. Furthermore, ICP-MS analysis revealed a magnesium and strontium content of 13.4% by mass, with a ratio of Mg:Sr = 1:3.2.

[0266] [Comparative Example 1-1]

[0267] The pre-crosslinked polymer particle group A1 obtained in Production Example 1 was designated as comparative polymer particle group BC-1.

[0268] [Comparative Example 1-2]

[0269] The following components were placed in a 300 mL flask, and a 30% by mass alcohol dispersion of the pre-crosslinked polymer particles A1 was prepared using a stirrer.

[0270] Polymer particle group A1 before cross-linking 30.0g

[0271] IPA 70.0 g

[0272] Next, slowly add 28.15 g of a 40% by mass aqueous calcium chloride solution, stir for 15 minutes, then add dropwise 50.0 g of purified water, and stir for 2 hours to perform a crosslinking treatment. After the stirring is completed, repeatedly filter and wash with ion-exchanged water, and powderize the final dispersion liquid with a freeze dryer to obtain a comparative polymer particle group BC-2 crosslinked only with calcium.

[0273] The comparative polymer particle group BC-2 was observed by SEM to confirm the shape, and the result was that the particle size was roughly the same as before the crosslinking treatment. In addition, the particle size distribution was confirmed by measuring the particle size distribution, and the result showed the same distribution as before the crosslinking treatment. Therefore, it was confirmed to be a non-aggregated, monodisperse particle group.

[0274] [Comparative Example 1-3]

[0275] Place the following components in a 300 mL flask, and use a stirrer to prepare a 30% by mass alcohol dispersion of the pre-crosslinked polymer particle group A1.

[0276] Pre-crosslinked polymer particle group A1 30.0 g

[0277] IPA 70.0 g

[0278] Next, slowly add 31.9 g of a 40% by mass aqueous strontium chloride solution, stir for 15 minutes, then add dropwise 50.0 g of purified water, and stir for 2 hours to perform a crosslinking treatment. After the stirring is completed, repeatedly filter and wash with ion-exchanged water, and powderize the final dispersion liquid with a freeze dryer to obtain a comparative polymer particle group BC-3 crosslinked only with strontium.

[0279] The comparative polymer particle group BC-3 was observed by SEM to confirm the shape, and the result was that the particle size was roughly the same as before the crosslinking treatment. In addition, the particle size distribution was confirmed by measuring the particle size distribution, and the result showed the same distribution as before the crosslinking treatment. Therefore, it was confirmed to be a non-aggregated, monodisperse particle group.

[0280] [Comparative Example 1-4]

[0281] Place all the following components in a 3000 mL flask at once, disperse the mixture with a disperser blade at 800 rpm to prepare a suspension, heat and stir at 80 °C in a nitrogen gas stream for 8 hours to obtain a particle dispersion liquid. Then, perform centrifugal separation 5 times repeatedly to carry out a classification and washing operation to prepare a comparative polymer particle group BC-4 as a single spherical polymer particle group of polymethyl methacrylate with an average particle size of 6 μm.

[0282]

[0283] The shapes, main raw materials, metals with a valence of 2 or more used for crosslinking, their contents, content ratios, maximum value of atomic radius difference (ΔR), and MV of the marine biodegradable polymer particle groups AC-1 to AC-12 and the comparative polymer particle groups BC-1 to BC-4 are summarized in Table 1.

[0284] [Table 1]

[0285]

[0286] The atomic radii of the metals that give metal cations with a valence of 2 or more used in the examples and comparative examples are as described below. Note that the atomic radii are cited from the values recorded in the Diploma Program (DP) Chemistry Data Book (Japanese version published in August 2015 (revised in May 2016), which is a Japanese translation of the English original Chemistry data booklet published in June 2014).

[0287] [Table 2]

[0288]

[0289] [2] Measurement of basic physical properties

[0290] [Examples 2-1 to 2-12, Comparative Examples 2-1 to 2-4]

[0291] For the marine biodegradable polymer particle groups AC-1 to AC-12 and the comparative polymer particle groups BC-1 to BC-4, the water absorption was measured by the following method, and the heat resistance, chemical resistance, and heat chemical resistance were evaluated.

[0292] [Measurement of water absorption]

[0293] Put 1 g of each particle group in a 500 mL beaker, then add 200 mL of ion-exchanged water, and perform suspension stirring for 30 minutes (150 rpm, 25 °C). Then transfer it to a 500 mL centrifuge tube, and use a centrifuge (himac CR20GII, manufactured by Koki Holdings Co., Ltd.) to perform centrifugation at 2000 G for 30 minutes. After centrifugation, gently discard the supernatant, take out the sample from the centrifuge tube, measure the weight (Ww), and then dry it in a dryer at 105 °C until it becomes a constant weight, and measure the dry weight (Dw). Calculate the water absorption by the following formula. The results are shown in Table 3.

[0294] Water absorption (mL / 100 g) = [(Ww - Dw) / Dw] × 100

[0295] [Evaluation of heat resistance]

[0296] Put 0.5 g of each particle group in an aluminum dish, heat it in a dryer at 180 °C for 2 hours, visually confirm the melting of the particles, confirm the shape by SEM, and evaluate according to the following evaluation criteria. The results are shown in Table 3.

[0297] [Evaluation Criteria]

[0298] Visual inspection: ○: No significant change, △: Partial melting, ×: Melting

[0299] SEM: 1: The shape of the particles is made, 2: The shape is maintained, and the surface is partially melted, 3: Partially melted and part of the particle shape is maintained, 4: No particle shape (completely melted)

[0300] [Evaluation of Chemical Resistance]

[0301] Put 1 g of each particle group and 99 g (1 mass%) of the solvent shown in Table 3 in a 300 mL flask, stir for 2 hours at room temperature (25 °C), visually confirm the dispersion state of the particles, confirm the shape by SEM, and evaluate according to the following evaluation criteria. The results are shown in Table 4.

[0302] [Evaluation of Heat-Resistant Chemical Resistance]

[0303] Put 1 g of each particle group and 99 g (1 mass%) of the solvent shown in Table 3 in a 300 mL flask, stir for 2 hours at 70 °C, visually confirm the dispersion state of the particles, confirm the shape by SEM, and evaluate according to the following evaluation criteria. The results are shown in Table 4.

[0304] [Evaluation Criteria]

[0305] ◎: Visually dispersed, and the shape of the particles is made in SEM

[0306] ○: Visually dispersed, the shape is maintained in SEM, and the surface is partially melted

[0307] △: Visually partially dispersed, and deformed in SEM

[0308] ×: Visually dissolved, and no shape in SEM

[0309] [Table 3]

[0310]

[0311] [Table 4]

[0312]

[0313] [3] Evaluation of Particle Softness (Evaluation of Compressive Strength Characteristics)

[0314] [Examples 3-1 to 3-12, Comparative Examples 3-1 to 3-4]

[0315] For each particle of the marine biodegradable polymer particle groups AC-1 to AC-12 and the comparative polymer particle groups BC-1 to BC-4, the 10% compression strength K at a 10% particle size displacement was evaluated using a micro compression testing machine MCT-W201 (manufactured by Shimadzu Corporation). 10 (Measurement temperature: 20°C). The results are shown in Table 5.

[0316] [Table 5]

[0317] Particle swarm <![CDATA[10% Compressive Strength K 10 (MPa)]]> Example 3-1 AC-1 80 Example 3-2 AC-2 135 Example 3-3 AC-3 70 Example 3-4 AC-4 75 Example 3-5 AC-5 55 Example 3-6 AC-6 120 Example 3-7 AC-7 135 Example 3-8 AC-8 90 Example 3-9 AC-9 140 Example 3-10 AC-10 75 Example 3-11 AC-11 115 Example 3-12 AC-12 85 Comparative Example 3-1 BC-1 Not measurable Comparative Example 3-2 BC-2 380 Comparative Example 3-3 BC-3 320 Comparative Example 3-4 BC-4 530

[0318] [4] Functional test and adhesion evaluation

[0319] [Examples 4-1 to 4-12, Comparative Examples 4-1 to 4-4]

[0320] For the marine biodegradable polymer particle groups AC-1 to AC-12 and the comparative polymer particle groups BC-1 to BC-4, the skin feel, slipperiness, and particle adhesion were evaluated using the following methods. The results are shown in Table 6.

[0321] (1) Skin feel

[0322] The feel when spreading each particle group on the skin was evaluated according to the following evaluation criteria.

[0323] (2) Slipperiness

[0324] 1 g of each particle group was placed on black synthetic leather, and the length when spreading with a finger was evaluated according to the following evaluation criteria.

[0325] (3) Particle adhesion

[0326] 1 g of each particle group was placed on black synthetic leather. After evenly spreading with a powder puff, the synthetic leather was patted 3 times, and the remaining amount of particles was observed using a digital microscope (VHX200 manufactured by Keyence Corporation), and evaluated according to the following evaluation criteria.

[0327] [Evaluation criteria]

[0328] ◎: Extremely good, ○: Good, △: Standard, ×: Poor

[0329] [Table 6]

[0330] Particle swarm MV (μm) Skin feel Slip property Particle adhesion Example 4-1 AC-1 6 〇 ◎ 〇 Example 4-2 AC-2 6 △ ○ 〇 Example 4-3 AC-3 6 ◎ ○ ○ Example 4-4 AC-4 6 ◎ 〇 ◎ Example 4-5 AC-5 6 ◎ ◎ ◎ Example 4-6 AC-6 6 ○ ◎ ○ Example 4-7 AC-7 6 ○ ○ ○ Example 4-8 AC-8 5 〇 ○ ○ Example 4-9 AC-9 30 ◎ ○ △ Example 4-10 AC-10 15 ◎ ○ 〇 Example 4-11 AC-11 10 ○ ○ ○ Example 4-12 AC-12 8 〇 △ ◎ Comparative Example 4-1 BC-1 6 △ △ 〇 Comparative Example 4-2 BC-2 6 △ △ 〇 Comparative Example 4-3 BC-3 6 △ △ ○ Example 4-4 BC-4 6 ○ ○ ○

[0331] Marine biodegradable polymer particle groups AC-1 to AC-12 exhibited properties comparable to or better than those of polymer particle group BC-4 in terms of skin feel and slippage. With regard to particle adhesion, comparable particle sizes were maintained. Furthermore, a trend was observed: a greater maximum difference in the metal cations used correlated with improved skin feel and slippage. On the other hand, for particle group BC-1, which was not crosslinked, skin feel and slippage tended to decrease as the hygroscopicity of the base particles deteriorated. Furthermore, for BC-2 and BC-3, which were crosslinked using a single ion, skin feel and slippage tended to decrease slightly due to the high crosslinking and hygroscopicity resulting from their egg-box structure.

[0332] [5] Sodium chloride aqueous solution solubility test (simulated seawater solubility test)

[0333] [Examples 5-1 to 5-12, Comparative Examples 5-1 to 5-4]

[0334] Marine biodegradable polymer particles AC-1 to AC-12 and comparative polymer particles BC-1 to BC-4 were dispersed in water and a 3% by mass sodium chloride aqueous solution to give a concentration of 0.1% by mass, respectively, and a solubility test was performed.

[0335] (1) Appearance: The appearance was visually checked 72 hours and 240 hours after dispersion.

[0336] (2) Shape: The change in shape after 72 hours and 240 hours of dispersion in a sodium chloride aqueous solution was confirmed by particle size distribution measurement.

[0337] The results are shown in Table 7.

[0338] [Table 7]

[0339]

[0340] Marine biodegradable polymer particles AC-1 to AC-12 are insoluble in water due to ionic crosslinking. However, in a sodium chloride aqueous solution dissolution test, they exhibited solubility comparable to that of comparative polymer particles BC-2 and BC-3, confirming that solubility remained unchanged even in structures using two or more metal cations. Meanwhile, comparative polymer particle group BC-1, which lacks a crosslinked structure, was found to dissolve in both water and sodium chloride aqueous solution. Furthermore, comparative polymer particle group BC-4, a general-purpose polymer particle group, was insoluble in all samples.

[0341] [6] Light diffusion evaluation

[0342] [Examples 6-1 to 6-12, Comparative Examples 6-1 to 6-4]

[0343] In a 20 mL sample bottle, a 0.1 mass% aqueous dispersion of each particle group was prepared. Next, the aqueous dispersions were respectively injected into quartz cells, and visible light at a wavelength of 560 nm and transmitted light analysis of UV at wavelengths of 400 nm and 320 nm were performed using an ultraviolet-visible spectrophotometer (UV-2450 manufactured by JASCO Corporation). The results are shown in Table 8.

[0344] [Table 8]

[0345]

[0346] From the results shown in Table 8, it was confirmed that the marine biodegradable polymer particle groups of the present invention had a decrease in transmitted light in the UV region, and thus had a significantly high UV scattering effect. In addition, it was confirmed that the scattering effect was also high in the visible light region, and thus the hiding power was also high.

[0347] [7] Production and Evaluation of Optical Measurement Sheets

[0348] [Examples 7-1 to 7-12, Comparative Examples 7-1 to 7-4]

[0349] To 15.0 g each of the marine biodegradable polymer particle groups AC-1 to AC-12 and the comparative polymer particle groups BC-1 to BC-4, 35.0 g of a binder resin (PVA resin manufactured by Kuraray Co., Ltd.) and 75.0 g of purified water were added and mixed to prepare a composition for an optical measurement sheet. Using a commercially available bar coater, each of the obtained compositions was coated on one side of a 100 μm thick PET film (E-5000 manufactured by Toyobo Co., Ltd.), and then the dryer was set at 60 °C and hot air drying was performed for 20 minutes to produce optical sheets 1 to 16 with a coating layer thickness of 40 μm.

[0350] For optical sheets 1 to 16, using an automatic variable-angle photometer (GonioPhotometer GP-200 manufactured by Murakami Color Research Institute Co., Ltd.), a certain amount of light was irradiated at an incident angle of 45°, and the light scattering distribution of the reflected light was measured, and the diffusion performance was evaluated according to the following evaluation criteria. The results are shown in Table 9.

[0351] [Evaluation Criteria]

[0352] Based on optical sheet 16 (polymer particle group BC-4),

[0353] A: Good diffusibility

[0354] B: Approximately the same diffusibility

[0355] C: Poor diffusibility

[0356] [Table 9]

[0357]

[0358] Confirmation: In the particle group crosslinked with metal cations of divalent or higher, properties equivalent to or better than those of the optical sheet 16 using the general polymer particle group BC-4 were obtained. In particular, there was the following tendency: the greater the maximum difference in metal cations used at the same particle size, the more advantageous the scattering characteristics were found to be.

[0359] [8] Optical properties and tactile evaluation in coatings

[0360] [Examples 8-1 to 8-12, Comparative Examples 8-1 to 8-4]

[0361] The marine biodegradable polymer particle groups AC-1 to AC-12 and the comparative polymer particle groups BC-1 to BC-4 were respectively added to a commercially available oil-based coating (PRO TOUCH manufactured by Rock Paint Co., Ltd.) to make it 5% by mass, coated on an aluminum substrate, dried, and a film with a dry film thickness of 2 μm was formed to produce coating film sheets 1 to 16.

[0362] The reflectivity of light and the presence or absence of gloss of the coating film sheets obtained by visual evaluation were subjected to a sensory evaluation of the tactile effect. The tactile effect was to run a finger across the coating film and evaluate the softness according to the following evaluation criteria. As a blank, an aluminum substrate without a film formed was used. The results are shown in Table 10.

[0363] [Evaluation criteria]

[0364] ○: Yes, △: Some (felt), ×: No

[0365] [Table 10]

[0366]

[0367] For the coating film sheets 1 to 12 containing the marine biodegradable polymer particle groups AC-1 to AC-12, it was shown that: compared with sheets 13 to 15, the effect of equivalent or higher hiding power was high, and it could be used as a matting agent and also as a tactile modifier.

[0368] [9] Seawater biodegradability evaluation

[0369] [Examples 9-1 to 9-12, Comparative Examples 9-1 to 9-4]

[0370] Using the marine biodegradable polymer particle groups AC-1 to AC-12, the comparative polymer particle groups BC-1 to BC-4, and microcrystalline cellulose (Avicel PH-101 manufactured by Sigma-Aldrich Corporation) as a control material, a seawater biodegradation test was carried out by the following method. The results are shown in Table 11.

[0371] <Test methods and conditions>

[0372] Method for measuring biodegradability: Measurement of oxygen consumption using a closed respirometer (refer to ASTM D6691)

[0373] Cultivation temperature: 30 ± 1°C, in the dark

[0374] Degree of biodegradability (%) = [(BOD O - BOD B ) / ThOD] × 100

[0375] BOD O : Biochemical oxygen demand for confirming the activity of the test or planting source (measured value: mg)

[0376] BOD B : Average biochemical oxygen demand of the blank test (measured value: mg)

[0377] ThOD: Theoretical oxygen demand required for the complete oxidation of the test material or control material (calculated value: mg)

[0378] Seawater: Sampled from Tokyo Bay (Chiba Prefecture: Chiba Port)

[0379] Number of samples: Set n = 3 for each type, and use the average value

[0380] [Evaluation criteria]

[0381] The cultivation period is 60 days. Calculate the ratio of the maximum biodegradability of each particle group to the biodegradability of microcrystalline cellulose (absolute biodegradability) as the relative biodegradability (%), and evaluate. It should be noted that the absolute biodegradability of cellulose as the control material is 66%.

[0382] ◎: Has the same seawater biodegradability as cellulose (relative biodegradability of 90% or more)

[0383] ○: Has the property of seawater biodegradability (relative biodegradability less than 60 - 90%)

[0384] △: May have the property of medium - to - long - term seawater biodegradability (relative biodegradability less than 10 - 60%)

[0385] ×: Highly likely to have almost no property of seawater biodegradability (relative biodegradability less than 10%)

[0386] [Table 11]

[0387] Particle swarm Relative biodegradability of cellulose (%) Evaluation of seawater biodegradability Example 9-1 AC-1 105 ◎ Example 9-2 AC-2 99 ◎ Example 9-3 AC-3 98 ◎ Example 9-4 AC-4 100 ◎ Example 9-5 AC-5 99 ◎ Example 9-6 AC-6 98 ◎ Example 9-7 AC-7 88 ○ Example 9-8 AC-8 100 ◎ Example 9-9 AC-9 92 ◎ Example 9-10 AC-10 94 ◎ Example 9-11 AC-11 100 ◎ Example 9-12 AC-12 92 ◎ Comparative Example 9-1 BC-1 110 ◎ Comparative Example 9-2 BC-2 105 ◎ Comparative Example 9-3 BC-3 101 ◎ Comparative Example 9-4 BC-4 0.3 × Control material Cellulose - 66% (absolute degradation degree)

[0388] From the results shown in Table 11, it can be confirmed that the particle swarm of the present invention has good biodegradability in seawater.

[0389]

[10] Preparation and Evaluation of Skin Cleansing Composition

[0390] [Examples 10-1 to 10-3, Comparative Example 10-1]

[0391] Using marine biodegradable polymer particle swarms AC-1, AC-9, AC-10 and comparative polymer BC-2, skin cleansing compositions (cleansing compositions 1 to 4) were prepared according to the composition shown in Table 12 below.

[0392] [Table 12]

[0393]

[0394] For each of the prepared cleansing compositions, the following method was used for evaluation. The results are shown in Table 13.

[0395] As an evaluation group, 10 people were selected and used the skin cleansing composition for a face-washing usage test. The six items of usage feeling 1, usage feeling 2, foaming property, skin dirt, cutin removal effect, massage effect, and irritation were evaluated respectively according to the following evaluation criteria. Based on this, a comprehensive evaluation as a scrub was carried out.

[0396] · Usage feeling 1: Good feeling of application during use and penetration into the skin

[0397] · Usage feeling 2: Little residue feeling of the scrub and skin tension after rinsing the cleaning agent

[0398] · Foaming property: Good foaming and foam persistence when using the cleaning agent

[0399] · Skin dirt, cutin removal effect: The shedding situation of the cosmetic after use

[0400] · Massage effect: Whether massage effects such as elimination of skin dullness, improvement of color, and promotion of blood circulation are felt after cleaning

[0401] · Irritation: Little redness, stinging pain, etc. after rinsing the cleaning agent

[0402] [Evaluation Criteria for Each Item]

[0403] ◎: Effective (good touch) [High evaluation by 8 or more people]

[0404] ○: Recognize the effect (slightly better touch) [High evaluation by 6 - 7 people]

[0405] □: Recognize the effect (slightly better touch) [High evaluation by 4 - 5 people]

[0406] △: Slightly ineffective (slightly poor touch feeling) [2 - 3 with high evaluation]

[0407] ×: Ineffective (poor touch feeling) [less than 1 with high evaluation]

[0408] [Score evaluation]

[0409] ◎: 8 points, ○: 6 points, □: 4 points, △: 2 points, ×: 0 points

[0410] [Comprehensive evaluation]

[0411] A: 38 points or more

[0412] B: 30 - 37 points

[0413] C: 22 - 29 points

[0414] D: 21 points or less

[0415] [Table 13]

[0416]

[0417] As shown in Table 13, it can be seen that the particle swarm of the present invention is also useful as an additive (raw material) for body cleansing compositions in terms of touch feeling and low irritation.

[0418] [Confirmation of skin cosmetics]

[0419] [Reference Examples 1 - 14]

[0420] According to the composition of Table 14 below, make color cosmetic compositions (foundations 1 - 14) containing marine biodegradable polymer particle swarms AC - 1 to AC - 12 and comparative polymers BC - 2 or BC - 4.

[0421] [Table 14]

[0422]

[0423] Similar to the commonly used compounding ingredients BC - 2 and BC - 4 in cosmetics, for the marine biodegradable polymer particle swarms AC - 1 to AC - 12 of the present invention, they can also be compounded as a cosmetic composition without inferiority. Therefore, it is confirmed that the raw materials using the particle swarm of the present invention can be applied to cosmetics in the same way as conventional materials.

[0424] As described above, regarding the marine biodegradable polymer particle group composed of a polymer compound formed by crosslinking a water-soluble polymer type polyvalent anion having a monovalent anionic substituent derived from alginic acid with two or more divalent or higher metal cations as the main component, since there are few foreign substances such as aggregates, it can be stably and efficiently manufactured. At the same time, crosslinked particles having heat resistance and chemical resistance (to heat) can also be stably produced, so it can be applied to various uses.

[0425] In addition, the marine biodegradable polymer particle group of the present invention is a particle with controlled particle size and environmentally friendly. In particular, as a component derived from natural polymers having a seawater biodegradation function that can be used for marine pollution countermeasures, it can be effectively used as coatings, inks, molded products, cosmetics, etc. for uses and additives required for the environment according to the use.

Claims

1. A marine biodegradable polymer particle group, comprising: a polymer compound formed by crosslinking a water-soluble polymer type polyvalent anion having a monovalent anionic substituent with two or more divalent or higher metal cations, wherein, the water-soluble polymer type polyvalent anion contains at least a component derived from alginic acid, the marine biodegradable polymer particle group satisfies the following conditions (1) to (4): (1) The content of the divalent or higher metal cations contained in the particle group is 3 to 30% by mass, (2) The difference between the maximum and minimum values of the atomic radius of the metal element that forms the divalent or higher metal cation is or more. (3) The content of metal cations with a valence of 2 or more from metal elements with an atomic radius of or more is 25% by mass or more among all metal cations with a valence of 2 or more. (4) The water absorption of the particle group is less than 300 mL / 100 g.

2. The marine biodegradable polymer particle population according to claim 1, wherein, The monovalent anionic substituent is a carboxylic acid anion.

3. The marine biodegradable polymer particle population according to claim 1, wherein, The water-soluble polymer type polyvalent anion is derived from polysaccharides.

4. The marine biodegradable polymer particle population according to claim 1, wherein, The difference between the maximum value and the minimum value of the atomic radius of the metal element that becomes the metal cation with a valence of 2 or more is as follows.

5. The marine biodegradable polymer particle population according to claim 1, wherein, The atomic radius of the metal element that becomes the metal cation with a valence of 2 or more is 6. The marine biodegradable polymer particle group according to claim 1, wherein, At least one of the two or more metal cations is beryllium ion, magnesium ion, calcium ion, strontium ion, barium ion, zinc ion or aluminum ion.

7. The marine biodegradable polymer particle population according to claim 6, wherein, At least one of the two or more metal cations is calcium ion or strontium ion.

8. The marine biodegradable polymer particle population according to claim 1, wherein, It further satisfies the following condition (5): (5) 10% compression strength K at 10% particle size displacement 10 is 1 to 1000 MPa.

9. The marine biodegradable polymer particle group according to claim 1, wherein, It further satisfies the following condition (6): (6) The melting temperature is 150 °C or higher.

10. A method for manufacturing a marine biodegradable polymer particle group, comprising a crosslinking step, wherein in (A) medium, (B) medium, or (C) medium, two or more salt compounds containing divalent or higher metal cations are used as crosslinking agents to crosslink the water-soluble polymer type polyvalent anions derived from the water-soluble anionic polymer, the (A) medium is a medium in which a water-soluble anionic polymer particle group having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is dispersed at a concentration of 5% by mass or more, the (B) medium is a medium in which a water-soluble anionic polymer having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is suspended or emulsified in water at a concentration of 5% by mass or more using water and an oily medium, the (C) medium is a medium in which a water-soluble anionic polymer having a monovalent anionic substituent containing at least a monovalent salt of alginic acid is hydrophilized or dissolved at a concentration of 5% by mass or more, Among them, The difference between the maximum and minimum values of the atomic radius of the metal element that is the metal cation with a valence of 2 or more contained in the salt compound is or more In such a manner that the content of divalent or higher metal cations of a metal element having an atomic radius of or more is 25 mass% or more among all divalent or higher metal cations, the two or more salt compounds are added in multiple portions to carry out a crosslinking reaction.

11. The method for producing the marine biodegradable polymer particle group according to claim 10, wherein, in the crosslinking step, at least one of the two or more salt compounds is added separately to carry out the crosslinking reaction.

12. An ultraviolet scattering agent, which is composed of the marine biodegradable polymer particle group according to any one of claims 1 to 9.

13. A marine biodegradable additive, which is composed of the marine biodegradable polymer particle group according to any one of claims 1 to 9.

14. A personal care product, which contains the marine biodegradable additive according to claim 13.

15. A cosmetic, which contains the marine biodegradable additive according to claim 13.

16. A coating, which contains the marine biodegradable additive according to claim 13.

17. An ink, which contains the marine biodegradable additive according to claim 13.

18. A resin composition, which contains the marine biodegradable additive according to claim 13.

19. A molded article, which contains the marine biodegradable additive according to claim 13.

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