JP6023929B2 - Ultraviolet-absorbing polymer fine particles and method for producing the same - Google Patents

Description

  The present invention relates to a polymer fine particle having ultraviolet absorptivity and a method for producing the same.

  Polymer fine particles of micron size (particle size of about 0.01 to several tens of μm) are organic pigments, toner particles, spacers for liquid crystal panels, separation materials, biochemical carriers, standard particles, fillers for cosmetics, various additives Or it is widely used for applications such as compounding agents. These polymer fine particles are required to have as uniform a particle size as possible from the viewpoint of ensuring fluidity.

  As a method for producing such micron-sized polymer fine particles, various production methods such as suspension polymerization, emulsion polymerization, and dispersion polymerization have been conventionally known (Patent Documents 1 and 2). However, when producing fine polymer particles with a uniform particle diameter by these production methods, it is necessary to delicately prepare the composition of the reaction solution, such as the amount of surfactant and stabilizer added to the reaction solution. It was. Therefore, it is difficult to produce polymer fine particles in which a secondary reactive functional group capable of surface modification is left for fixing a chemical substance or a biological substance and using it as a carrier for biochemistry. It was.

  As a method for producing such polymer fine particles that can be surface-modified by eliminating such drawbacks, conventionally, an organic solvent containing diethylene glycol dimethacrylate, which is a crosslinkable monomer, is irradiated with radiation (gamma rays), Methods for producing molecular fine particles have been studied (see Non-Patent Documents 1 to 3).

  This radiation-based polymerization method uses a uniform system of only a crosslinkable monomer and an organic solvent without adding a surfactant or a stabilizer to a polymer particle having a uniform particle size in which secondary reactive functional groups remain on the surface. The solution can be produced without stirring. However, since a radiation irradiation facility is required, there is a problem that it is difficult to manufacture easily and at a low cost.

  Further, as a method for producing a large amount of polymer fine particles from a monomer-solvent system by radical polymerization, polymerization using an initiator that generates radicals upon heating is common. However, the fine particle synthesis by radical polymerization is performed by using a monomer, a solvent that does not dissolve the polymer fine particles, a surfactant that stabilizes the heterogeneous solution or a stabilizer that prevents the polymer fine particles from binding, a polymerization initiator that generates radicals, These are put into a reaction vessel, oxygen that reacts with radicals to stop chain reaction is removed by nitrogen bubbling or the like, and heated with stirring to carry out radical polymerization reaction. Thus, production of polymer fine particles by radical polymerization requires preparation of a complex solution composition and stirring operation during the synthesis reaction, and it is difficult to produce polymer fine particles with a uniform particle size. There was a problem.

  Patent Document 3 discloses a polymer fine particle having a secondary reactive functional group that can be modified on the surface and having a uniform particle size, eliminating the drawbacks of the method for producing the polymer fine particle as described above. Patent Document 3 discloses a method for obtaining a raw material solution by dissolving a crosslinkable monomer in an organic solvent, and a polymerization initiator in the raw material solution. Alternatively, a step of adding a polymerization initiator solution to obtain a reaction solution, a step of adding a polymerization initiator or a polymerization initiator solution to the raw material solution, stirring during the induction period to obtain a reaction solution, and a reaction solution And a method of producing a polymer fine particle comprising a step of heating and allowing to undergo a polymerization reaction in a stationary state.

  On the other hand, polymer fine particles having ultraviolet absorptivity are desired as ultraviolet absorbers used in cosmetics, antireflection films (antiglare films) and the like.

  As the ultraviolet absorbing material, a polymer material produced from a polymerizable compound containing a portion having an ultraviolet absorbing ability derived from hydroxycinnamic acid is known (Patent Documents 4 and 5). The polymerizable compounds disclosed in Patent Documents 4 and 5 can be obtained easily and in large amounts from nature, and even when the phenolic hydroxyl group is blocked, the ultraviolet absorption ability hardly changes even when the phenolic hydroxyl group is blocked on the phenolic hydroxyl group side. ) A polymerizable compound in which an acrylic acid unit or the like is bonded. Since this polymerizable compound does not need to leave a free phenolic hydroxyl group, it can be synthesized by a simple method of reacting a phenolic hydroxyl group. Further, it has an excellent property that it does not easily change over time such as discoloration caused by the phenolic hydroxyl group, and has a great advantage in terms of product quality. Furthermore, since such a polymerizable compound can be produced by a simple process without using a petroleum-derived raw material which is a depleted resource, it can suppress wasteful energy consumption and is a preferable material from the viewpoint of green chemistry. .

JP 59-181301 JP-A-63-3316766 JP 2007-197565 A JP 2009-215189 A JP 2011-144287 A

Yoshida et al., "Character of polymer microspheres prepared by radiation-induced polymerization in the presence of organic solvents", Radiation physics and chemistry (Radiat Phys. Chem.), Elsevier, 1987, volume 30, number 1, p. 39-45 Y. Naka et al. “Preparation of Microspheres by Radiation-Induced Polymerization. 1.Mechanism for the Formation of Monodisperse Poly (diethylene glycol dimethacrylate) Microspheres), Polymer Science Journal Part A (J. Polym. Sci., Part A, Polym. Chem. Ed.), USA, Jone Wily & Sons, Inc., 1991, Vol. 29, No. 8, p. 1197-1202 Y. Naka et al., “Preparation of Microspheres by Radiation-Induced Polymerization. 2. Mechanism of Microsphere Growth.”, Journal of Polymer Science, A (J. Polym. Sci., Part A, Polym. Chem. Ed.), USA, Jone Wily & Sons, Inc., 1992, Volume 30, No. 7, p. 1287-1298

  An object of the present invention is to provide a novel ultraviolet-absorbing fine particle containing a portion having an ultraviolet-absorbing ability derived from hydroxycinnamic acid and a simple production method thereof.

  The present invention relates to a highly UV-absorbing high polymer comprising a copolymer of a hydroxycinnamic acid derivative having at least one polymerizable functional group and a crosslinkable monomer having at least two other polymerizable functional groups. Molecular fine particles.

  It is preferable that the hydroxyl group of the hydroxycinnamic acid derivative is converted to another substituent.

  The substituent is preferably at least one functional group selected from the group consisting of an acetyl group, an ester group, an ether group and a urethane group.

  It is preferable that the dynamic friction force of the base material coated with the polymer fine particles is smaller than the dynamic friction force of the base material coated with the titanium oxide powder fine particles.

  The copolymerization molar ratio of the hydroxycinnamic acid derivative and the crosslinkable monomer is preferably 1:99 to 50:50.

  The polymer fine particles preferably have a particle size of 0.01 to 10 μm. The crosslinkable monomer is preferably diethylene glycol dimethacrylate. The hydroxycinnamic acid is preferably ferulic acid.

Further, the present invention is a method for producing polymer fine particles having ultraviolet absorptivity,
And a step of copolymerizing a hydroxycinnamic acid derivative having at least one polymerizable functional group and a crosslinkable monomer having at least two other polymerizable functional groups in a solvent. The present invention also relates to a method for producing polymer fine particles having ultraviolet absorption.

  The solvent is preferably at least one solvent selected from the group consisting of ester solvents, ether solvents, ketone solvents, and hydrocarbon solvents.

  In the copolymerization step, the reaction solution containing the hydroxycinnamic acid derivative, the crosslinkable monomer, the polymerization initiator and the solvent is stirred during an induction period until the copolymerization reaction is started, and then the reaction solution It is preferable to carry out the copolymerization reaction by heating in a state of standing.

  In the present invention, it is possible to provide a novel polymer fine particle containing a portion having an ultraviolet absorbing ability derived from hydroxycinnamic acid and a simple production method thereof.

  In addition, since the method for producing polymer fine particles of the present invention does not require special equipment such as radiation irradiation equipment, it is easy to increase the synthetic scale. Therefore, polymer fine particles having ultraviolet absorptivity can be produced easily and in large quantities, and the production cost can be reduced. Further, the obtained polymer fine particles having ultraviolet absorptivity have an advantage that a smoother skin feel can be obtained than conventional fine particles for cosmetics (such as commercially available titanium oxide for cosmetics).

It is a graph which shows the measurement result of ultraviolet-ray absorption ability about the polymer microparticles (white solid) obtained in Example 1. It is a graph which shows the measurement result of ultraviolet-ray absorption capability about the polymer microparticles (white solid) obtained in Example 2. It is a graph which shows the measurement result of ultraviolet-ray absorption ability about the polymer fine particle (white solid) obtained in Example 3. It is a graph which shows the measurement result of ultraviolet-ray absorption ability about the polymer microparticles (white solid) obtained in Example 4. It is a graph which shows the measurement result of ultraviolet absorption ability about the polymer fine particle (white solid) obtained in Example 9. It is the image obtained by SEM about the white solid obtained in Example 1. It is the image obtained by SEM about the white solid obtained in Example 2. FIG. It is the image obtained by SEM about the white solid obtained in Example 3. It is the image obtained by SEM about the white solid obtained in Example 4. It is the image obtained by SEM about the white solid obtained in Example 9.

<Polymer fine particles>
The polymer fine particle of the present invention comprises a copolymer of a hydroxycinnamic acid derivative having at least one polymerizable functional group and a crosslinkable monomer having at least two other polymerizable functional groups, and absorbs ultraviolet rays. It has sex.

(Crosslinkable monomer)
The crosslinkable monomer used in the present invention is a monomer having at least two polymerizable functional groups. The polymerizable functional group is preferably a radical polymerizable functional group. Examples of the radical polymerizable functional group include a (meth) acryl group, and among these, a (meth) acryl group is preferable. Specific examples of the crosslinkable monomer include diethylene glycol di (meth) acrylate. Among them, diethylene glycol dimethacrylate can be preferably used.

  In the reaction solution, a non-crosslinkable monomer other than the hydroxycinnamic acid derivative and the crosslinkable monomer may be added as long as the copolymerization reaction for obtaining desired polymer fine particles is not inhibited. Examples of the crosslinkable monomer include styrene monomers, acrylamide, acrylic acid esters such as acrylic acid and methyl acrylate, and methacrylic acid esters such as methacrylic acid and methyl methacrylate. Further, a non-crosslinkable monomer having secondary reactivity such as maleic anhydride, glycidyl methacrylate, hydroxylethyl methacrylate, methacryloyloxyethyl isocyanate, acryloyloxyethyl isocyanate may be added.

(Hydroxycinnamic acid)
Hydroxycinnamic acid is a derivative having at least one hydroxyl group in the aromatic ring of the cinnamic acid skeleton, and includes a derivative having a methoxy group in addition to a hydroxyl group on the aromatic ring and a derivative having two or more hydroxyl groups. The hydroxycinnamic acid used in the present invention is not particularly limited in its origin, but it is derived from, for example, cell walls such as rice bran oil, sugar maple, pine seeds, wheat endosperm cell walls, rice endosperm cells, etc. Things. In the case of using hydroxycinnamic acid derived in this manner, it is not necessary to use a petroleum-derived raw material that is a depleted resource for the ultraviolet absorption site in the production of a hydroxycinnamic acid derivative having a polymerizable functional group.

  Examples of such hydroxycinnamic acid include ferulic acid, 4-hydroxycinnamic acid, 3,4-dihydroxy cinnamic acid (caffeic acid), 4-hydroxy-3,5-dimethoxy cinnamic acid (sinapic acid), 2- Although hydroxycinnamic acid is mentioned, ferulic acid is preferably used.

(Hydroxycinnamic acid derivative having a polymerizable functional group)
A hydroxycinnamic acid derivative having at least one polymerizable functional group is used as one monomer in the copolymerization reaction. The polymerizable functional group is preferably a radical polymerizable functional group. Examples of the radical polymerizable functional group include a (meth) acryl group, a vinyl ether group, an allyl group, a methallyl group, a propargyl group, and a crotyl group, and a (meth) acryl group is preferable.

  The specific hydroxycinnamic acid derivative is not particularly limited as long as it contains a portion having the ability to absorb ultraviolet light of hydroxycinnamic acid, and is exemplified in Patent Document 4 (Japanese Patent Application Laid-Open No. 2009-215189), for example. A polymerizable compound having a single polymerizable functional group (monofunctional polymerizable compound) or a polymerizable compound having a plurality of polymerizable functional groups exemplified in Patent Document 5 (Japanese Patent Application Laid-Open No. 2011-144287) ( Polyfunctional polymerizable compounds).

  The ferulic acid derivative is preferably one in which a hydroxyl group derived from a ferulic acid derivative having a polymerizable functional group is converted to another substituent. The other substituent is not particularly limited as long as it does not inhibit the initiation of polymerization by chain transfer or the like, but preferably at least one functional group selected from the group consisting of an ester group, an ether group and a urethane group It is. Examples of the ester group include an acetyl group, a benzoyl group, and a (meth) acryloyl group, and an acetyl group is preferable.

  When the ferulic acid derivative has a hydroxyl group, a period from when the polymerization initiator is added to the reaction solution containing the ferulic acid derivative and the crosslinkable monomer until the copolymerization reaction starts (“induction period”) It has been found by the present inventors that there is a tendency to be longer (for example, about 2 hours). For this reason, in the above ferulic acid derivative, by converting the hydroxyl group derived from ferulic acid having a polymerizable functional group into another substituent, the total reaction time can be shortened, and the polymer fine particles having ultraviolet absorptivity Can be efficiently manufactured.

  The copolymerization molar ratio of the ferulic acid derivative and the crosslinkable monomer is preferably 1:99 to 50:50, more preferably 2:98 to 40:60. When the amount of the ferulic acid derivative is less than 1:99, there is a problem that the ultraviolet absorption ability is remarkably reduced. From 50:50, when the amount of the ferulic acid derivative is large, gelation tends to occur. Because.

(Particle size)
The particle diameter of the polymer fine particles is preferably 0.01 to 100 μm, more preferably 0.01 to 10 μm. The particle diameter of the polymer fine particles can be measured by a known method, for example, a method of observing the polymer fine particles with a scanning electron microscope. The particle size distribution can also be measured by a known method, for example, a method using a laser diffraction particle size distribution measuring apparatus. The variation in the particle size distribution of the polymer fine particles can be evaluated by, for example, the magnitude of CV value (%) {(standard deviation / average particle size) × 100}, and the value is preferably 10%. Below, more preferably 5% or less.

(Thermal characteristics)
As described in JP 2010-116523 A, polymer fine particles are heated in various manufacturing and processing steps, so that the fine particles may be fused and may not exhibit their original performance. Therefore, as a property of the fine particles of the present invention, it is desirable that when thermal analysis (differential scanning calorimetry) is performed, a peak of 1.00 mW / min or higher does not appear at 50 ° C. or lower during temperature rise measurement.

(Dynamic frictional force)
In the case of fine particles for cosmetics, smoothness of the touch is required as a tactile sensation because they directly touch the skin. As an index of touch, the dynamic friction force of the base material coated with fine particles can be used. Specifically, it can be evaluated by applying fine particles on artificial skin for cosmetic evaluation and comparing with fine particles such as before and after application and general titanium oxide.

<Manufacture of polymer fine particles>
The method for producing polymer fine particles having ultraviolet absorptivity according to the present invention includes a step of performing a copolymerization reaction between the ferulic acid derivative and the crosslinkable monomer different from the above in a solvent. Hereinafter, an example of the method for producing polymer fine particles of the present invention using the above-described ferulic acid derivative, a crosslinkable monomer, a solvent, a polymerization initiator and the like will be specifically described.

(1) Preparation of raw material solution The ferulic acid derivative and the crosslinkable monomer described above are dissolved in a solvent to form a raw material solution. This raw material solution is put in a reaction vessel, and a polymerization initiator added in a later step generates radicals. The raw material solution is heated together with the reaction vessel up to the temperature (polymerization temperature).

(solvent)
Solvents for dissolving the ferulic acid derivative and the crosslinkable monomer are those that dissolve the ferulic acid derivative and the crosslinkable monomer, a polymerization initiator, and other necessary auxiliary agents, and do not dissolve the polymer fine particles after polymerization. The organic solvent can be used without any particular limitation, but an organic solvent is preferred.

  Examples of such an organic solvent include good solvents for the crosslinkable monomer, and preferably at least one solvent selected from the group consisting of ester solvents, ether solvents, ketone solvents, and hydrocarbon solvents. . Specific examples include esters such as ethyl acetate and propyl acetate, and ketones such as acetone, acetonitrile and diethyl ketone. It is desirable not to use an alcohol solvent as the organic solvent. This is because the use of a solvent having a hydroxyl group such as alcohol tends to significantly slow the initiation of polymerization.

  The amount of the solvent used is preferably 300 to 5000% by weight, more preferably 500 to 2000% by weight, based on the total amount of the ferulic acid derivative and the crosslinkable monomer. When the amount of the solvent used is less than 300% by weight, there is a problem that the shape deteriorates and the whole solution is gelled. When the amount exceeds 5000% by weight, fine particles are not formed or a sufficient yield can be obtained. Problems such as being unable to do so occur.

(Bubbling)
In addition, you may bubble the raw material solution etc. before adding a polymerization initiator by inert gas, such as nitrogen gas. In general, in the presence of oxygen, the polymerization initiator reacts with oxygen first, so it is known that the more the oxygen in the atmosphere, the slower the start of the copolymerization reaction, and the oxygen contained in the raw material solution is reduced by bubbling. By expelling and reducing the oxygen concentration in the raw material solution, the time (induction period) until the polymerization reaction starts can be shortened.

  However, in the production method of the present invention, if the induction period becomes too short, a sufficient time for stirring the reaction solution cannot be secured, and the temperature of the reaction solution at the start of polymerization, the polymerization initiator It becomes difficult to make the concentration distribution uniform. In order to make the temperature of the reaction solution at the start of polymerization and the concentration distribution of the polymerization initiator more uniform and to obtain polymer fine particles having a good shape and particle size distribution, the bubbling time is appropriately optimized within a predetermined range. It is preferable.

  However, in order to simplify the production process, a ferulic acid derivative having a hydroxyl group derived from ferulic acid having a polymerizable functional group converted with another substituent is used as a ferulic acid derivative without bubbling a raw material solution or the like. It is preferable to adjust the induction period to an appropriate period. The induction period is preferably adjusted to 1 to 60 minutes, more preferably 5 to 30 minutes.

(2) Preparation of polymerization initiator The polymerization initiator used in the present invention is preferably an oil-soluble radical polymerization initiator. Examples of the oil-soluble radical polymerization initiator include azobis-based initiators, organic peroxides, and derivatives of these polymerization initiators. Preferred are azo compounds (azobis-based initiators) and organic peroxides.

  Examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 4,4′-azobis (4-cyanopentanoic acid), 2 , 2'-azobis (2-methylbutyronitrile), azobiscyclohexanecarbonitrile.

  Examples of organic peroxides include cumene hydroperoxide, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, o-chlorobenzoyl peroxide, acetyl peroxide, t-butyl hydroperoxide, and t-butyl peroxide. Examples thereof include acetate, t-butyl peroxyisobutyrate, 3,5,5-trimethylhexanoyl peroxide, t-butyl peroxy-2-ethylhexanoate, and di-t-butyl peroxide.

  Further, the amount (addition amount) of the polymerization initiator is preferably 0.1 to 30% by weight based on the total amount of monomers to be polymerized (the ferulic acid derivative and the crosslinkable monomer), and more Preferably it is 0.1-5 weight%, Most preferably, it is 0.1-1 weight%. When the amount of the polymerization initiator used is less than 0.1% by weight, problems such as insufficient polymerization reaction or a long time for polymerization occur. However, there are problems such as the yield does not change or decreases, and particles having a bad shape are formed due to rapid progress of the reaction.

  Since the polymerization initiator is dissolved in the reaction solution (raw material solution) in a short time, it may be prepared as a solution dissolved in a solvent separately from the raw material solution. As the solvent for dissolving the polymerization initiator, it is preferable to use the same solvent as the solvent of the reaction solution. The polymerization initiator is preferably stored at a temperature slightly lower than the temperature at which the polymerization initiator generates radicals, specifically at about 40 to 120 ° C.

(3) Preparation of reaction solution A polymerization initiator or a solution of a polymerization initiator is added to the raw material solution in the reaction vessel and stirred to obtain a reaction solution. In addition, it is preferable to stir the reaction solution only during the induction period (the period from the addition of the polymerization initiator to the start of the polymerization reaction). That is, unlike ordinary thermal polymerization, it is preferable not to stir the reaction solution during the polymerization reaction. This is because when the polymer particles are allowed to stand without stirring during the polymerization reaction, the generated polymer particles are prevented from adhering to each other, and uniform polymer particles are easily obtained.

(4) Polymerization reaction The reaction solution homogenized by stirring in the above (3) is allowed to stand for a predetermined time without stirring. After the elapse of a predetermined time, the reaction solution is cooled to stop the synthesis reaction, the polymer fine particles are filtered from the reaction solution with a membrane filter or the like, and the filtered polymer fine particles are washed with a solvent. In this way, polymer fine particles having ultraviolet absorptivity can be obtained.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. In each of the following examples, the following monomers A to G were used as ferulic acid derivatives having at least one polymerizable functional group.

<Monomer A: EF-GMA>
A reaction product of ethyl ferulate and glycidyl methacrylate represented by the following chemical formula.

<Monomer B: FA-2GMA>
A reaction product of ferulic acid and glycidyl methacrylate represented by the following chemical formula.

<Monomer C: EF-GMA-Ac>
A reaction product of ethyl ferulate and glycidyl methacrylate represented by the following chemical formula, wherein a hydroxyl group derived from ferulic acid having a polymerizable functional group is acetylated.

<Monomer D: FA-2GMA-Ac>
A reaction product of ferulic acid and glycidyl methacrylate represented by the following chemical formula, wherein a hydroxyl group derived from ferulic acid having a polymerizable functional group is acetylated.

<Monomer E: FA-2HBAGE>
A reaction product of ferulic acid and 4-hydroxybutyl acrylate glycidyl ether represented by the following chemical formula.

<Monomer F: FA-2A400>
A reaction product of ferulic acid and 3,4-epoxycyclohexylmethyl acrylate represented by the following chemical formula.

<Monomer G: EF-HBAGE>
A reaction product of ethyl ferulate and 4-hydroxybutyl acrylate glycidyl ether represented by the following chemical formula.

(Measurement of particle diameter)
In the following examples, the particle size is measured by dispersing polymer fine particles in a neutral detergent aqueous solution having a concentration of 0.2% by weight and carrying out ultrasonic treatment, followed by a laser diffraction particle size distribution analyzer (Shimadzu Corporation). Measurement was performed using SALD-3100). The values of the refractive index used for the measurement were 1.60 (real part) and 0.00 (imaginary part).

Example 1
To a glass screw tube having an internal volume of 100 ml, 9.6 g of diethylene glycol dimethacrylate (hereinafter abbreviated as “2G”) as a crosslinkable monomer, 1.6 g of monomer A (EF-GMA) as a ferulic acid derivative, , 100 mL of ethyl acetate was added and stirred to dissolve the contents uniformly and heated at 60 ° C. for 30 minutes.

  Next, 1.01 g of 2,2′-azobis (2-methylpropionic acid) dimethyl (hereinafter abbreviated as “V-601”) as a polymerization initiator was charged into the glass screw tube. Thereafter, the screw tube was sealed and kept at 60 ° C. in a heating oven. Heating was continued for 2 hours after charging the polymerization initiator.

  The screw tube was taken out from the heating oven, the content was filtered through a membrane filter having a pore size of 1 μm, and the obtained solid was dried under reduced pressure to obtain 8.0 g of polymer fine particles (white solid). The obtained polymer fine particles had a particle size of 2.55 ± 0.08 μm and a CV value of 3.0%.

  In addition, when 3.00 mg of fine particles were collected and placed in a container, and differential scanning calorimetry was performed from −30 ° C. to 180 ° C. at a rate of temperature increase of 20 ° C./min, 1 mW / min or more in the region up to 50 ° C. No heat in and out was observed. The copolymerization molar ratio of the ferulic acid derivative and the crosslinkable monomer at this time is 1: 9 :.

(Example 2)
10.7 g of polymer fine particles (white solid) were obtained in the same manner as in Example 1 except that 2.1 g of monomer B (FA-2GMA) was used instead of monomer A. In addition, the time from the addition of V-601 to the content becoming milky white was 60 minutes. The obtained fine polymer particles had a particle size of 0.55 ± 0.09 μm and a CV value of 17%. Further, differential scanning calorimetry was performed in the same manner as in Example 1. As a result, no heat in / out of 1 mW / min or more was observed in the region up to 50 ° C. The copolymerization molar ratio of the ferulic acid derivative and the crosslinkable monomer at this time is 1: 9.

[Acetylated ferulic acid derivative]
(Example 3)
The amount of 2G was 1.0 g, the amount of ethyl acetate was 10 mL, the amount of initiator V-601 was 0.2 g, and instead of monomer A, 0.42 g of monomer C (EF-GMA-Ac: hydroxyl group of monomer A) In the same manner as in Example 1, except that acetylated one was used, 1.1 g of polymer fine particles (white solid) were obtained. Note that the time from the addition of V-601 until the content became milky white was shortened to 18 minutes. The obtained polymer fine particles had a particle size of 2.45 ± 0.07 μm and a CV value of 3%. Further, differential scanning calorimetry was performed in the same manner as in Example 1. As a result, no heat in / out of 1 mW / min or more was observed in the region up to 50 ° C. The copolymerization molar ratio of the ferulic acid derivative and the crosslinkable monomer at this time is 2: 8.

Example 4
The amount of 2G is 0.5 g, the amount of ethyl acetate is 10 mL, the amount of initiator V-601 is 0.2 g, and instead of monomer A, 0.29 g of monomer D (FA-2GMA-Ac: hydroxyl group of monomer B) In the same manner as in Example 1, except that acetylated one was used, 0.59 g of polymer fine particles (white solid) were obtained. The time required from the addition of V-601 until the content became milky white was reduced to 16 minutes. The obtained polymer fine particles had a particle size of 1.06 ± 0.12 μm and a CV value of 11%.

  Further, as in Example 1, differential scanning calorimetry was performed, and as a result, heat in and out of 1 mW / min or higher was not observed in the region up to 50 ° C. The copolymerization molar ratio of the ferulic acid derivative and the crosslinkable monomer at this time is 2: 8.

[Other ferulic acid derivatives]
(Example 5)
The amount of 2G added was 10.1 g, and 7.9 g of polymer fine particles (white solid) was used in the same manner as in Example 1 except that 1.3 g of monomer F (FA-2A400) was used instead of monomer A. ) In addition, the time from the addition of V-601 to the content becoming milky white was 85 minutes. Observation with a microscope confirmed that spherical fine particles were obtained. Moreover, the copolymerization molar ratio of the ferulic acid derivative and the crosslinkable monomer at this time is 1:19.

(Example 6)
The amount of 2G added was 10.1 g, and 7.5 g of polymer fine particles (white solid) was used in the same manner as in Example 1 except that 0.9 g of monomer G (EF-HBAGE) was used instead of monomer A. ) In addition, the time from the addition of V-601 to the content becoming milky white was 60 minutes. Observation with a microscope confirmed that spherical fine particles were obtained. Moreover, the copolymerization molar ratio of the ferulic acid derivative and the crosslinkable monomer at this time is 1:19.

[Scale-up]
(Example 7)
252.5 g of 2G, 20.0 g of monomer A (EF-GMA), and 2100 g of ethyl acetate are placed in a stainless steel pressure vessel having an internal volume of 3 L, and the contents are uniformly dissolved by stirring. For 30 minutes.

  Next, 25.25 g of V-601 dissolved in 125 g of ethyl acetate was put into the stainless steel pressure vessel, and then the vessel was sealed and immersed in a 60 ° C. warm bath. When the pressure vessel was opened every 10 minutes and the contents were confirmed, the contents became milky white after 40 minutes, and heating was continued for another 60 minutes from that point.

  The pressure vessel was removed from the warm bath, the contents were filtered through a membrane filter having a pore size of 1 μm, and the resulting solid was dried in an air oven at 70 ° C. for 1 day to obtain 185.7 g of polymer fine particles (white solid). Observation with a microscope confirmed that spherical particles were obtained. The copolymerization molar ratio of the ferulic acid derivative and the crosslinkable monomer at this time is 1:19.

(Example 8)
The point that 26.3 g of monomer B (FA-2GMA) was used instead of monomer A, and it took 70 minutes after the addition of V-601 until the content became milky white, and further warmed for 120 minutes from that point. 204.3 g of polymer fine particles (white solid) were obtained in the same manner as in Example 5 except that the above was continued. Observation with a microscope confirmed that spherical particles were obtained. The copolymerization molar ratio of the ferulic acid derivative and the crosslinkable monomer at this time is 1:19.

Example 9
The point that 32.5 g of monomer E (FA-2HBAGE) was used in place of monomer A, and 65 minutes were required until the content became milky white after addition of V-601. Except for these points, 211.7 g of polymer fine particles (white solid) were obtained in the same manner as in Example 5. The obtained fine polymer particles had a particle size of 2.98 ± 0.09 μm and a CV value of 2.9%. Moreover, the copolymerization molar ratio of the ferulic acid derivative and the crosslinkable monomer at this time is 1:19.

[Measurement of UV absorption capacity]
The polymer fine particles (white solids) obtained in Examples 1 to 4 and 9 using monomers A to E were confirmed for ultraviolet absorption ability. The measurement was performed in a reflective mode using an ISR-240A with an integrating sphere with a UV-2550 manufactured by Shimadzu Corporation. Each measurement result is shown in FIGS. It was confirmed that any of the polymer fine particles obtained in Examples 1 to 4 and 9 have ultraviolet absorbing ability of a specific wavelength derived from the ferulic acid-derived portion and function sufficiently as ultraviolet absorbing fine particles. It was.

[SEM (scanning electron microscope) observation]
The white solids obtained in Examples 1 to 4 and 9 using monomers A to E were observed by SEM (scanning electron microscope). The image obtained by SEM about each white solid is shown in FIGS. In any white solid obtained in Examples 1 to 4 and 9, formation of fine particles could be confirmed. In addition, many of the particles have a relatively uniform particle size, and it has been clarified that highly uniform particles are obtained. In addition, when the monomer B and the monomer D were used, the particle diameter of the fine particles tended to be slightly smaller than when 2G and the monomers A and C were used.

[Dynamic friction force measurement]
Measurement of dynamic friction force as an index of touch feeling when white solids (polymer fine particles) obtained in Examples 1, 2, 4, and 9 using monomers A, B, D, and E are used in cosmetics and the like. (However, in the case where monomer D was used, the charged composition ratio was the same as in Example 4, but it was synthesized under scaled-up conditions). For comparison, the same measurement was performed for titanium oxide fine particles (manufactured by Pinoa Co., Ltd., trade name: titanium oxide) marketed for cosmetics and a base material to which fine particles were not applied.

Specifically, according to a unique test method, a sufficient amount of fine particles (0.2 g per 20 cm ² ) was applied on a base material (bioskin), and a circular bioskin with a diameter of 1.5 cm separate from the base material was applied. It was placed on a substrate and a 50 g weight was placed on it. By pulling the end of the circular bioskin, the circular bioskin with a 50 g weight was moved on the substrate, and the dynamic friction force was measured. The moving speed of the circular bi-skin with respect to the base material was 300 mm / min. As a base material (bioskin) and a circular bioskin, Bioskin (artificial skin for cosmetic evaluation) manufactured by Beaulac was used. Table 1 shows the measurement results of the obtained dynamic friction force.

  As shown in Table 1, the dynamic frictional force of the base material (bioskin (blank)) to which fine particles are not applied is about 0.8 to 1N. On the other hand, the fine particles are applied on the base material. In either case, it can be seen that the dynamic friction force is reduced and the smoothness is improved. Further, in any of the polymer fine particles obtained in Examples 1, 2, 4 and 9, the dynamic friction force was smaller than that of the titanium oxide fine particles for cosmetics of the comparative example, and the polymer of the present invention. It can be seen that the fine particles are useful as fine particles for cosmetics with improved touch feeling.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The polymer fine particles of the present invention are used as UV absorbers for cosmetics, antireflection films (antiglare films), weather-resistant polycarbonate for outdoor use, outdoor paints for automobiles, clear top coating materials, inkjet printing materials, glasses, contact lenses. It is used for a light guide plate for a liquid crystal back panel.

Claims (10)

  A hydroxycinnamic acid derivative in which a compound having at least one polymerizable functional group is bonded to the hydroxyl group of hydroxycinnamic acid having at least one hydroxyl group on the aromatic ring of the cinnamic acid skeleton, and at least 2 different from this Polymer fine particles having ultraviolet absorptivity comprising a copolymer of a crosslinkable monomer having one polymerizable functional group. The new hydroxyl group caused by the binding of a compound having a polymerizable functional group and said hydroxy group of the hydroxycinnamic acid is converted to another substituent, polymer particle according to claim 1.   The polymer fine particle according to claim 2, wherein the substituent is at least one functional group selected from the group consisting of an acetyl group, an ester group, an ether group, and a urethane group.   The polymer fine particle according to any one of claims 1 to 3, wherein a copolymerization molar ratio between the hydroxycinnamic acid derivative and the crosslinkable monomer is 1:99 to 50:50.   The polymer fine particles according to any one of claims 1 to 4, wherein the particle diameter is 0.01 to 10 µm.   The polymer fine particles according to claim 1, wherein the crosslinkable monomer is diethylene glycol dimethacrylate.   The polymer fine particles according to any one of claims 1 to 6, wherein the hydroxycinnamic acid is ferulic acid. A method for producing polymer fine particles having ultraviolet absorptivity,
And a step of copolymerizing a hydroxycinnamic acid derivative having at least one polymerizable functional group and a crosslinkable monomer having at least two other polymerizable functional groups in a solvent. A method for producing polymer fine particles having ultraviolet absorptivity.   The production method according to claim 8, wherein the solvent is at least one solvent selected from the group consisting of an ester solvent, an ether solvent, a ketone solvent, and a hydrocarbon solvent.   In the copolymerization step, the reaction solution containing the hydroxycinnamic acid derivative, the crosslinkable monomer, the polymerization initiator and the solvent is stirred during an induction period until the copolymerization reaction is started, and then the reaction solution The method for producing polymer fine particles according to claim 8 or 9, wherein the copolymerization reaction is carried out by heating in a state of standing.