JP6859564B2 - Polymer fine particles - Google Patents

Description

The present invention relates to polymer fine particles. More specifically, the present invention relates to rotaxane copolymerization system polymer fine particles.

In Patent Document 1, a solvent-based coating material contains _{a modified polyrotaxane having a -CO (CH 2} ) ₅ OH group, which is a caprolactone modifying group, and silica or alumina fine particles having an average particle size of less than 380 nm, and is a coating film forming component. A fine particle-polyrotaxane-containing paint having a modified polyrotaxane content of 35 to 76.5% by mass is described.

It is stated that this fine particle-polyrotaxane-containing paint can achieve excellent scratch resistance and chemical resistance.

Japanese Unexamined Patent Publication No. 2015-45028

Macromolecules 1993, Vol. 26, pp. 5698-5703

An object of the present invention is to provide rotaxane copolymerization system polymer fine particles that form polymer fine particles by themselves.

An object of the present invention is to prepare a rotaxane copolymer which is a copolymer of a rotaxane having a polymerizable unsaturated group in both a cyclic molecule and a linear molecule encapsulated therein and a polymerizable unsaturated monomer. It is achieved by polymer fine particles composed of crosslinked products.

The rotaxane copolymer system polymer fine particles according to the present invention itself form polymer fine particles having an average particle diameter of 2000 nm or less. The obtained polymer fine particles having a rotaxane network become a flexible and tough network polymer due to the sliding effect derived from the rotaxane network, and are effectively used as an organic filler.

Rotaxane is a compound in which a cyclic polymer is penetrated with a shaft polymer (linear molecule). Since the conventionally known rotaxane has a reactive functional group only for the cyclic compound in its structure, a plurality of reactive functional group-containing cyclic compounds are required in order to exert the sliding effect.

Rotaxane copolymerization system of the present invention High polymer fine particles, particularly those having a polymerizable unsaturated group which is a reactive functional group in both a cyclic compound and a shaft polymer (linear molecule), can be used as a rotaxane even if only one type of cyclic compound is used. The sliding effect of is exhibited, and this is the biggest feature.

Further, since the rotaxane copolymer system polymer fine particles show a sliding effect, the effect of containing water is large, and the swelling degree is about 1.5 to 2 times that of the chemically crosslinked copolymer.

It is a figure which showed typically the sliding effect of the rotaxane copolymer system polymer fine particle which concerns on this invention. It is a graph of the stress-strain curve when DVB is used as a cross-linking agent instead of the polymers 2a, 2b or the rotaxane compound in the polymer. It is a figure which showed typically the structure of the rotaxane copolymer system polymer fine particle obtained by the emulsion polymerization of an Example.

The rotaxane, consists bulky blocking group for the cyclic molecules, linear molecules and cyclic molecules clathrate cyclic molecule with piercing through the cyclic molecule to prevent desorption from the linear molecule, the cyclic molecule and it inclusion Those having a polymerizable unsaturated group in both of the linear molecules are used.

The cyclic molecule constituting the rotaxane is a molecule in which a linear molecule is encapsulated in a skewer shape at its opening, and is not particularly limited as long as it has an OH group, and is preferably α-cyclodextrin, for example. , Β-cyclodextrin, γ-cyclodextrin and the like. The cyclic molecule may have a group other than the above-mentioned active group such as 2,6-dimethyl-β-cyclodextrin. Further, the cyclic molecule may be a crown ether.

Examples of groups other than active groups include acetyl group, propionyl group, hexanoyl group, methyl group, ethyl group, propyl group, 2-hydroxypropyl group, 1,2-dihydroxypropyl group, cyclohexyl group, butylcarbamoyl group and hexylcarbamoyl. Examples thereof include a group, a phenyl group, a polycaprolactone group, an alkoxysilane group, an acryloyl group, a methacryloyl group or a cinnamoyl group, a polymer chain (polycaprolactone group, a polycarbonate group, etc.), or a derivative thereof. Further, the active group may be directly bonded to the cyclic molecule, or may be bonded to the cyclic molecule via a group other than the active group.

The linear molecule is not particularly limited as long as it can be included in the opening of the cyclic molecule in a skewered manner. For example, the linear molecule includes polyvinyl alcohol, polyvinylpyrrolidone, and poly (meth) acrylic acid. , Cellular resins (carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, etc.), polyacrylamides, polyethylene glycols, polypropylene glycols, polyvinyl acetal resins, polyvinyl methyl ethers, polyamines, polyethyleneimines, caseins, gelatins, starches, etc. and / or these Polypolymers, polyethylene, polypropylene and polyolefin resins such as copolymers of ethylene and other olefin monomers, polyester resins, polyvinyl chloride resins, polystyrene resins such as polystyrene, polymethylmethacrylate, (meth) Acrylic resins such as acrylic acid ester copolymers, polycarbonate resins, polyurethane resins, vinyl chloride-vinyl acetate copolymer resins, polyvinyl butyral resins and the like, derivatives or modified products thereof, polyisobutylene, poly tetrahydrofuran, polyaniline, nylon and the like. Polysiloxanes, polyimides, polysiloxanes such as polydimethylsiloxane, polysulfones, polyimines, polyan acetates, polyureas, polysulfides, polyphosphazenes, polyketones, polyphenylenes, polyhaloolefins and these. It is better to be selected from the group consisting of derivatives of. For example, it is preferably selected from the group consisting of polyethylene glycol, polyisobutylene, polyisobutylene, polybutadiene, polypropylene glycol, polytetrahydrofuran, polydimethylsiloxane, polyethylene, polypropylene, polyvinyl alcohol and polyvinyl methyl ether. Polyethylene glycol is particularly preferable. Hexifluorite phosphate with an amino group is also preferred.

In the rotaxane copolymer system polymer fine particles according to the present invention, even one cyclic molecule such as crown ether or cyclodextrin exhibits a function (sliding effect) as a rotaxane copolymer, so that it is directly used as a shaft polymer. The chain molecule preferably has a weight average molecular weight Mw of 100 or more, preferably 300 to 100,000, and more preferably 500 to 50,000.

As described above, in the rotaxan copolymerization system polymer fine particles, at least one cyclic molecule is included in the linear molecule as the axial polymer, and the reaction point is not only in the cyclic molecule but also in the axial polymer. The number of cyclic molecules encapsulated in a skewered manner with respect to one linear molecule is 1 to about 5000, preferably 1 to about 3000, and more preferably 1 to about 1000. The maximum inclusion amount of the cyclic molecule can be determined by the length of the linear molecule and the thickness of the cyclic molecule. For example, when the linear molecule is polyethylene glycol and the cyclic molecule is an α-cyclodextrin molecule, the maximum inclusion amount has been experimentally determined (see Non-Patent Document 1).

The blocking group is not particularly limited as long as it is a group that is arranged near both ends of the polyrotaxane and acts to prevent the cyclic molecule from being eliminated. For example, dinitrophenyl groups, adamantan groups, trityl groups, fluoresceins, silsesquioxanes, pyrenes, unsubstituted or substituted benzenes as blocking groups (alkyl, alkoxy, hydroxy, halogen, cyano as substituents). , Sulfonyl, carboxyl, amino, phenyl and the like, but not limited to these, one or more substituents may be present), optionally substituted polynuclear aromatics (as the substituents above). , But not limited to these, and one or more substituents may be present), and may be selected from the group consisting of steroids. It is preferable to select from the group consisting of dinitrophenyl groups, adamantane groups, trityl groups, fluoresceins, silsesquioxanes and pyrenes, and more preferably adamantane groups or trityl groups. Good. Dimethylphenyl isocyanate is also preferred.

As the polyrotaxane as described above, a commercially available product can be used. For example, SH3400P manufactured by Advanced Soft Materials Co., Ltd. can be used as it is.

A polymerizable unsaturated group, which is a reactive functional group, is introduced into both the cyclic molecule and the linear molecule encapsulated therein.

Examples of the polymerizable unsaturated group include a vinyl group, an acrylic group, and a methacrylic group. For example, the introduction of a methacrylic acid group is carried out using 2-isocyanatoethyl methacrylate.

The introduction of a polymerizable unsaturated group into a cyclic molecule, or a linear molecule encapsulated therein, mixes the cyclic molecule with the linear molecule encapsulated therein, and after inclusion, the cyclic molecule and / or the linear molecule. It is carried out by introducing a polymerizable functional group into a hydroxyl group or the like of a state molecule by an esterification reaction or the like, and a rotaxan having a polymerizable unsaturated group can be obtained.

As the polymerizable unsaturated monomer copolymerized with rotaxane having a polymerizable unsaturated group, a vinyl compound, an acrylic acid derivative, a methacrylic acid derivative and the like are used.

As the vinyl compound, for example, a styryl compound having a vinyl group on the benzene ring, alkyl vinyl, aromatic vinyl, allele, allene, diene, alkyne and the like are used, and among them, styryl compound, alkyl vinyl, aromatic vinyl, allyl and diene. Is preferable.

Examples of the acrylic acid derivative include alkyl esters or alkenyl esters having 50 or less carbon atoms such as methyl, ethyl, propyl, n-butyl, hexyl, 2-ethylhexyl, octyl, oleyl, palmityl, and stearyl of acrylic acid or acrylic acid, and methoxy. An alkoxyalkyl ester having an alkoxyalkyl group having 2 to 50 carbon atoms or an alkenyloxyalkyl group such as methyl, methoxyethyl, ethoxyethyl, n-butoxyethyl, or an alkenyloxyalkyl ester is used, and n-butyl acrylate is particularly preferable. ..

As the methacrylic acid derivative, methacrylic acid or a methacrylic acid ester corresponding to the above acrylic acid derivative is used, and methyl methacrylate is particularly preferable.

For copolymerization of rotaxane having a polymerizable unsaturated group and a polymerizable unsaturated monomer , the former is about 0.001 to 10 mol%, preferably about 0.01 to 1 mol%, and the latter is about 99.999 in the total amount of both. It is carried out using ~ 90 mol%, preferably about 99.99-99 mol%. That is, the former acts as a crosslinkable group of the produced rotaxane copolymer.

The copolymerization reaction is carried out by any polymerization method such as emulsion polymerization, turbid polymerization, solution polymerization and bulk polymerization in the presence of a commonly used radical initiator, preferably an emulsion polymerization method. As the radical initiator, a redox system in which tertiary butyl hydroperoxide and sodium formaldehyde sulfoxylate, ammonium persulfate and sodium hydrogen sulfite, etc. are used in combination, preferably tertiary butyl hydroperoxide and sodium formaldehyde sulfoxylate may be used. it can. In the case of emulsion polymerization, which is a preferred polymerization method, the polymerization reaction is carried out in the presence of various surfactants. A chain transfer agent can be used in the polymerization reaction.

Examples of the surfactant include sodium lauryl sulfate, sodium oleate, sodium alkylsulfonate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene alkyl ether sulfate and the like or equivalent potassium or calcium salts, polyoxyethylene lauryl ether, etc. Polyethylene glycol fatty acid ester, polyoxyethylene alkylaryl sodium and the like are preferably used, and sodium lauryl sulfate and polyoxyethylene lauryl ether are preferably used.

As the chain transfer agent, n-dodecyl mercaptan, octyl mercaptan, α-methylstyrene dimer, 1,4-terpinolene and the like are preferably used, and n-dodecyl mercaptan is preferably used. The molecular weight becomes smaller, and the breaking strength and Mooney viscosity ML _{1 + 4} (100 ℃) become smaller. The chain transfer agent is used in an amount of about 0.001 to 0.05 parts by weight, preferably about 0.0035 to 0.01 parts by weight, per 100 parts by weight of the total amount of the charged monomers.

The polymerization reaction is carried out by an arbitrary method such as a batch method or a continuous or intermittent addition method at a temperature of about -10 to 100 ° C., preferably about 2 to 80 ° C. The copolymer is separated after the reaction is completed by different methods depending on the polymerization method. For example, in the case of an emulsion polymerization method or a turbid polymerization method, an acid or a polyvalent metal salt is added to the reaction mixture as necessary. It is carried out by the addition of a coagulant such as, and the separated copolymer is subjected to a washing and drying step. During the emulsion polymerization reaction, cross-linking by self-cross-linking is also performed at the same time.

The obtained rotaxane copolymer system polymer fine particles are in the form of polymer fine particles having an average particle diameter of about 2000 nm or less, preferably about 1500 to 50 nm, and the molecular weight thereof is about 300 to 100,000.

As shown in FIG. 1, the polymer fine particles having the rotaxane network become a flexible and tough network polymer due to the sliding effect derived from the rotaxane copolymer network, and are effectively used as an organic filler.

As shown in the graph of the stress-strain curve in FIG. 2, polyrotaxane, which has not been introduced with a polymerizable unsaturated group and has not been copolymerized with a polymerizable unsaturated monomer, is copolymerized with divinylbenzene [DVB]. Compared with the case of cross-linking using as a cross-linking agent, remarkable stretching was confirmed in the rotaxane copolymer system polymer fine particles of the present invention, and the flexibility derived from the polymerizable unsaturated group, which is a cross-linking group, contributed to this. It is thought that it has been done.

Next, the present invention will be described with respect to Examples.

Example 1
Acrylic type rotaxane synthesis method:
0.150 g (0.39 mmol) of hexafluorophosphate of a shaft polymer having an amino group and 0.260 g (0.41 mmol) of crown ether containing a methacrylic acid ester site as a cyclic molecule are mixed in 1 mL of dehydrated dichloromethane and irradiated with ultrasonic waves. did. After that, 10 μL of dibutyltin dilaurylate (a product of Aldrich) and 0.160 g (1.1 mmol) of 3,5-dimethylphenylisocyanate (a product of Tokyo Chemical Industry) were added, and the mixture was stirred at room temperature for 5 hours to seal the ends of the shaft polymer. went.

The rotaxane compound solution was washed with a small amount of methanol and roughly purified, and then the obtained rotaxane compound, triethylamine (Wako Pure Chemical Industries, Ltd.) 0.81 g (8.0 mmol) and 2-isosianatoethyl methacrylate (Aldrich) were obtained. Product) Dissolve 0.62 g (4.0 mmol) in 4.0 mL of tetrahydrofuran, stir at room temperature for 2.5 days, then purify with a silica gel column (dichloromethane / ethyl acetate (v / v = 1/1)) and preparative GPC. Obtained 0.290 g (25 mmol, 64%) of acrylic type rotaxane (MW 1171).
Emulsion polymerization:
Acrylic type rotaxane (crosslinking agent) 0.03g (0.05 mol%)
n-Butyl Acrylate-Methyl Methacrylate 6.41g (99.95 mol%)
(Mole ratio 40:60) Mixture
n-Butyl Acrylate (Wako Pure Chemical Industries, Ltd.) 2.95g
Methyl methacrylate (the company's product) 3.46g
Sodium dodecylbenzene sulfonate 0.10g
(Tokyo Chemical Industry products)
After emulsifying the mixed solution of the above with ultrasonic waves, a radical initiator is added to the emulsion, and the polymerization reaction is carried out at 70 ° C. for 4 hours to obtain 6.07 g of polymer fine particles which are crosslinked products of these copolymers. Obtained. (See Fig. 3)

The harmonic mean diameter Dh of the obtained polymer fine particles was measured by a particle size measuring machine (Zetasizer Nano S manufactured by Malvern Co., Ltd.) and an analysis method: a cumulant method.

Example 2
In Example 1, the amount of rotaxane cross-linking agent in the copolymer was changed to 0.03 mol%.

Example 3
In Example 1, the amount of rotaxane cross-linking agent in the copolymer was changed to 0.10 mol%.

The results obtained in each of the above examples are shown in the following table.
table
Example Polymer cross-linking agent amount (mol%) Dh (nm) conversion rate (%) yield (%)
1 2b 0.05 103 89 81
2 2a 0.03 111 97 93
3 2c 0.10 106 94 88

Claims (6)

Polymer fine particles composed of crosslinked products of rotaxane copolymer, which is a copolymer of a rotaxan having a polymerizable unsaturated group in both a cyclic molecule and a linear molecule encapsulated therein and a polymerizable unsaturated monomer. .. The polymer fine particles according to claim 1, wherein the harmonic mean diameter is 2000 nm or less. The polymer fine particles according to claim 1, wherein a rotaxane having a polymerizable unsaturated group at at least one end of the linear molecule is used. The polymer fine particles according to claim 1 or 3, wherein the polymerizable unsaturated group is a vinyl group, an acrylic group or a methacrylic group. The polymer fine particles according to claim 1, wherein the polymerizable unsaturated monomer is a vinyl compound, an acrylic acid ester, or a methacrylic acid ester. A cyclic molecule, a linear molecule in which the cyclic molecule is skewered, and a cyclic molecule are composed of a bulky blocking group for preventing detachment from the linear molecule, and the cyclic molecule and the direct inclusion in the cyclic molecule. A rotaxan having a polymerizable unsaturated group on both chain molecules.

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