JP7304037B2 - block copolymer - Google Patents

Description

The present invention relates to novel block copolymers.

In recent years, various surface modification techniques using polymer materials and the like have been investigated for the purpose of imparting antifouling properties, antifogging properties, dispersibility of inorganic particles, and the like.

Patent Document 1 discloses an inkjet recording ink containing water, a water-soluble compound, a pigment, and a (meth)acrylic acid ester-based random copolymer having an acid value of 100 mgKOH/g or more and 160 mgKOH/g or less for dispersing the pigment. is disclosed.

Patent Document 2 describes antifogging and antistatic properties for various members containing at least a hydrophobic segment and a hydrophilic segment, the hydrophilic segment containing at least monomer units of a cationic monomer and an anionic monomer. A block polymer capable of imparting properties and the like is disclosed.

Patent Document 3 discloses a pigment dispersion containing a pigment, a liquid medium and a polymer dispersant, wherein the polymer dispersant is a block polymer represented by AB or ABC; The block and C block are polymer blocks composed of ethylenically unsaturated monomers having no amino group and hydroxyl group, and the B block is a polymer block composed of a monomer having a glycidyl group or an isocyanate group, through a glycidyl group or an isocyanate group. A pigment dispersion is disclosed which is a polymer block to which either one of an amino compound and a compound having a hydroxyl group is bound.

JP 2015-052058 A JP 2017-179112 A WO2010/016523

There are various demands for polymers used as surface treatment agents. For example, in sunscreen cosmetics that use inorganic particles such as titanium oxide for scattering ultraviolet rays, conventionally, such inorganic particles have been used. A polymer that can further improve dispersibility and the like has been desired.

Accordingly, an object of the present invention is to provide a novel block copolymer that can be used as a surface treatment agent capable of imparting various properties such as dispersibility to objects such as inorganic particles.

式１中、
Ｒ^１は、水素又はメチル基であり、かつ
ｍは、０～２１の整数であり、

式２中、
Ｒ^１は、水素又はメチル基であり、
Ｒ^２及びＲ^３は、それぞれ独立に、炭素原子数１～６のアルキル基であり、
ｍは、１～６の整数であり、かつ
ｎは、５～７０の整数であり、

式３中、
Ｒ^１は、水素又はメチル基である。
〈態様２〉
前記式１のＲ^１が、メチル基であり、ｍが、１０～１５の整数であり、
前記式２のＲ^１及びＲ^２が、メチル基であり、Ｒ^３が、ブチル基であり、ｍが、１～３の整数であり、ｎが、１０～６０の整数であり、かつ
前記式３のＲ^１が、メチル基である、態様１に記載のブロックコポリマー。
〈態様３〉
前記疎水性セグメントの割合が、５０～９９モル％であり、かつ、前記親水性セグメントの割合が、１～５０モル％である、態様１又は２に記載のブロックコポリマー。
〈態様４〉
式１及び式２から選択される少なくとも一種のモノマーを用い、リビングラジカル重合法により疎水性セグメントを形成し、次いで、式３のモノマーを用い、リビングラジカル重合法により親水性セグメントを形成し、又は
式３のモノマーを用い、リビングラジカル重合法により親水性セグメントを形成し、次いで、式１及び式２から選択される少なくとも一種のモノマーを用い、リビングラジカル重合法により疎水性セグメントを形成する、
態様１～３の何れか一項に記載のブロックコポリマーの製造方法。
〈態様５〉
リビングラジカル重合法が、ヨウ素化合物を開始化合物とし、リン化合物、窒素化合物又は酸素化合物を触媒とする重合法である、態様４に記載の方法。<Aspect 1>
A block copolymer comprising a hydrophobic segment and a hydrophilic segment,
The hydrophobic segment comprises a monomer unit composed of at least one monomer selected from the following formulas 1 and 2,
wherein the hydrophilic segment comprises a monomer unit composed of a monomer of formula 3 below,
Block copolymer:

In formula 1,
R ¹ is hydrogen or a methyl group, and m is an integer from 0 to 21,

In formula 2,
R ¹ is hydrogen or a methyl group,
R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms,
m is an integer from 1 to 6, and n is an integer from 5 to 70,

In formula 3,
R ¹ is hydrogen or a methyl group.
<Aspect 2>
R ¹ in Formula 1 is a methyl group, m is an integer of 10 to 15,
R ¹ and R ² in formula 2 are methyl groups, R ³ is a butyl group, m is an integer of 1 to 3, n is an integer of 10 to 60, and the formula The block copolymer of embodiment ^{1, wherein R 1} of 3 is a methyl group.
<Aspect 3>
3. The block copolymer according to aspect 1 or 2, wherein the proportion of the hydrophobic segment is 50-99 mol % and the proportion of the hydrophilic segment is 1-50 mol %.
<Aspect 4>
Using at least one monomer selected from formulas 1 and 2, forming a hydrophobic segment by a living radical polymerization method, then using a monomer of formula 3 to form a hydrophilic segment by a living radical polymerization method, or Using the monomer of formula 3, forming a hydrophilic segment by a living radical polymerization method, then using at least one monomer selected from formulas 1 and 2, forming a hydrophobic segment by a living radical polymerization method,
A method for producing a block copolymer according to any one of aspects 1-3.
<Aspect 5>
The method according to aspect 4, wherein the living radical polymerization method is a polymerization method using an iodine compound as an initiator compound and a phosphorus compound, a nitrogen compound, or an oxygen compound as a catalyst.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a novel block copolymer that can be used as a surface treatment agent capable of imparting various properties such as dispersibility to objects such as inorganic particles.

(a) is a schematic diagram of an object surface-treated with a block copolymer, (b) is a schematic diagram of an object surface-treated with a random copolymer, and (c) is a low-molecular type surface. 1 is a schematic diagram of an object surface-treated with a treating agent; FIG. 1 is a schematic diagram of an object surface-treated with a block copolymer according to one embodiment of the present invention; FIG.

Embodiments of the present invention will be described in detail below. The present invention is not limited to the following embodiments, and can be modified in various ways within the scope of the spirit of the invention.

The block copolymer of the present invention comprises a hydrophobic segment and a hydrophilic segment, the hydrophobic segment comprising monomer units composed of at least one monomer selected from the following formulas 1 and 2, and hydrophilic A block copolymer in which the segments comprise monomeric units composed of the monomers of formula 3 below.

式１中、
Ｒ^１は、水素又はメチル基であり、かつ
ｍは、０～２１の整数であり、

式２中、
Ｒ^１は、水素又はメチル基であり、
Ｒ^２及びＲ^３は、それぞれ独立に、炭素原子数１～６のアルキル基であり、
ｍは、１～６の整数であり、かつ
ｎは、５～７０の整数であり、

式３中、
Ｒ^１は、水素又はメチル基である。

In formula 1,
R ¹ is hydrogen or a methyl group, and m is an integer from 0 to 21,

In formula 2,
R ¹ is hydrogen or a methyl group,
R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms,
m is an integer from 1 to 6, and n is an integer from 5 to 70,

In formula 3,
R ¹ is hydrogen or a methyl group.

Although not limited by the principle, it is believed that such a block copolymer can impart surface treatment performance to an object as follows. Here, a case where inorganic particles are adopted as the object will be exemplified.

For example, when a random copolymer is prepared from a hydrophobic monomer and a hydrophilic monomer, the copolymer has a hydrophobic site and a hydrophilic site randomly arranged in the copolymer, so the random copolymer as a whole , it exhibits an intermediate performance that is a mixture of hydrophobicity and hydrophilicity. On the other hand, in the case of a block copolymer, a hydrophobic segment composed of a hydrophobic monomer and a hydrophilic segment composed of a hydrophilic monomer are separately formed in the copolymer. Different pieces of properties such as gender can be imparted.

For example, when an oil containing inorganic particles surface-treated with a commonly used low-molecular-weight surface treatment agent is emulsified by blending it with a cosmetic or the like, aggregation and precipitation tend to occur. It is thought that part of the low-molecular-weight surface treatment agent desorbs from the inorganic particles and migrates into the cosmetic, resulting in a lack of stability due to the exposed portions on the surface of the inorganic particles. ing. On the other hand, the block copolymer of the present invention has a specific hydrophobic segment and a specific hydrophilic segment, and at least part of the hydrophilic segment among these is adsorbed to the inorganic particles via a plurality of adsorption points. Alternatively, it adsorbs to the surface of the inorganic particles, and in some cases, hydrogen bonding occurs between the inorganic particles and the hydrophilic segment, making it difficult for the copolymer to desorb from the inorganic particles, improving the dispersion stability of the inorganic particles. I think I'm letting you.

It is also believed that in the oil phase, the hydrophobic segments in the copolymer exhibit a comb structure and are oriented outward with respect to the inorganic particles, for example, as shown in FIG. . As a result, compared with random copolymers and low-molecular-weight surface treatment agents, as shown in (b) and (c) of FIG. It is believed that the dispersibility of the inorganic particles is further improved because the precipitation can be further suppressed.

Further, for example, when inorganic particles are blended into a water-in-oil type cosmetic, the inorganic particles produced by conventional surface treatment generally tend to significantly increase the viscosity of the cosmetic. Inorganic particles surface-treated with a block copolymer of , do not significantly increase the viscosity of the cosmetic.

This is because, for example, inorganic particles surface-treated with a random copolymer exhibit a structure in which hydrophilic and hydrophobic moieties cling to the particles, as shown in FIG. It is considered that the particles are dispersed in the oil phase in close proximity to each other because the affinity layer with the oil phase based on the hydrophobic part is low and the affinity layer with the oil phase is thin.

Inorganic particles surface-treated with a conventional low-molecular-weight surface treatment agent also have a short hydrophobic portion and low steric hindrance, as shown in FIG. Since the affinity layer is thin, the particles are considered to be dispersed in the oil phase in close proximity to each other. As a result, the inorganic particles surface-treated with these materials exhibit a state in which the particles are densely packed with oil, which is thought to increase the viscosity of cosmetics and the like.

On the other hand, the inorganic particles surface-treated with the block copolymer of the present invention have an affinity layer with the oil phase due to the hydrophobic segment, as shown in FIG. It is believed that the oil existing between the particles can flow more freely because the particles are dispersed relatively far apart and the particles are covered more thickly than in the configuration of . As a result, it is thought that the viscosity increase of cosmetics etc. can be suppressed.

Therefore, for example, when titanium oxide or the like is surface-treated with the block copolymer of the present invention, such particles can be highly dispersed with good dispersibility without significantly increasing the viscosity of the sunscreen cosmetic or the like. We believe that it can improve performance such as applicability to the skin and sun protection performance.

《Block Copolymer》
In the block copolymer of the present invention, the ratio of the hydrophobic segment of formula 1 or formula 2 in the copolymer is 50 mol% or more, 55 mol% or more, or 60 mol%, considering the performance expression based on the hydrophobic segment. 99 mol % or less, 95 mol % or less, or 90 mol % or less. Considering the adsorptivity to the object, etc., the ratio of the hydrophilic segment in formula 3 can be 1 mol% or more, 5 mol% or more, or 10 mol% or more, and 50 mol% or less, 45 mol% % or 40 mol % or less.

The molecular weight of the block copolymer of the present invention is not particularly limited. ,000 to 20,000. Also, the molecular weight distribution, which is the ratio of the number average molecular weight to the weight average molecular weight, can be in the range of 1.05 to 5, preferably in the range of 1.05 to 1.7.

<Hydrophobic segment>
The monomer unit composed of at least one monomer selected from formulas 1 and 2 in the hydrophobic segment takes into consideration the required surface treatment performance, affinity with the dispersion medium in which the object surface-treated with the block copolymer is blended, etc. can be selected as appropriate.

例えば、極性油のような分散媒を使用する場合に採用することが好ましい。(monomer of formula 1)
The monomer of Formula 1 below is

For example, it is preferably employed when using a dispersion medium such as polar oil.

In Formula 1, R ¹ is hydrogen or a methyl group, and m is an integer of 0-21. From the viewpoint of dispersibility, expression of performance such as low viscosity, etc., R ¹ is preferably a methyl group, and m is preferably an integer of 3 or more, 5 or more, 8 or more, or 10 or more. , and preferably an integer of 20 or less, 18 or less, or 15 or less. Here, the (CH ₂ ) _m moiety in Formula 1 may be linear or branched, but preferably linear.

例えば、シリコーン油のような分散媒のときに採用することが好ましい。(monomer of formula 2)
The monomer of Formula 2 below is

For example, it is preferable to use a dispersion medium such as silicone oil.

In Formula 2, R ¹ is hydrogen or a methyl group, R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms, m is an integer of 1 to 6, and , n is an integer from 5 to 70. From the viewpoint of dispersibility, low viscosity, etc., R ¹ and R ² in Formula 2 are preferably methyl groups, R ³ is preferably a butyl group, and m is an integer of 1 to 3. n is preferably an integer of 6 or more, 8 or more, or 10 or more, and preferably an integer of 60 or less, 50 or less, or 40 or less. Here, the (CH ₂ ) _m moiety in Formula 1 may be linear or branched, but preferably linear.

親水性セグメントのモノマー単位を構成し、対象物の表面に吸着する部位を形成する。<Hydrophilic segment>
(monomer of formula 3)
The monomer of Formula 3 below is

It constitutes the monomer unit of the hydrophilic segment and forms a site that adsorbs to the surface of the object.

In Formula 3, R ¹ is hydrogen or a methyl group. From the viewpoint of polymerizability of the block copolymer, etc., R ¹ is preferably a methyl group.

<Arbitrary monomer>
The block copolymer of the present invention may further have monomer units composed of monomers other than the monomers of the formulas 1 to 3 as long as the effects of the present invention are not impaired. The proportion of such monomer units can be in the range of 30 mol % or less, 20 mol % or less, 10 mol % or less, or 5 mol % or less of the total amount of constituent monomer units. Examples of such monomers include acrylamide, methacrylamide, methylacrylamide, methylmethacrylamide, dimethylmethacrylamide, ethylacrylamide, ethylmethacrylamide, diethylmethacrylamide, N-isopropylacrylamide, N-vinylpyrrolidone, ε-caprolactam, and vinyl alcohol. , maleic anhydride, N,N'-dimethylaminoethyl methacrylic acid, diallyldimethylammonium chloride, alkyl acrylate, alkyl methacrylate, N,N'-dimethylacrylamide, styrene and the like.

<Method for producing block copolymer>
The block copolymer of the present invention can be obtained by a known living radical polymerization method. For example, using at least one monomer selected from the above formulas 1 and 2, a hydrophobic segment is formed by a living radical polymerization method, and then using a monomer of the above formula 3, a hydrophilic segment is formed by a living radical polymerization method. Segments can be formed to give block copolymers. Alternatively, using the monomer of formula 3 above, a hydrophilic segment is formed by a living radical polymerization method, and then at least one monomer selected from the above formulas 1 and 2 is used to form a hydrophobic segment by a living radical polymerization method. Segments can be formed to give block copolymers.

The living radical polymerization method is a method in which a catalyst, a chain transfer agent, or the like is added to a conventional radical polymerization method to control the reactivity of the terminal active radicals, thereby allowing the polymerization to proceed in a pseudo-living manner. The molecular weight distribution can be narrowed compared to ordinary radical polymerization, and the molecular weight can be controlled. As the known living radical polymerization method, specifically, the living radical polymerization method using a nonmetallic catalyst disclosed in International Publication No. 2010/016523, etc., the metal complex disclosed in International Publication No. 96/030421, etc. ATRP method by addition, TEMPO method of introducing thermally dissociable groups disclosed in U.S. Pat. RAFT polymerization method, Chem. Iniferter method with a photo-thermally dissociable group disclosed in Express 5 (10), 801 (1990) and the like can be mentioned.

Among them, the living radical polymerization method using a non-metallic catalyst is preferable because it is inexpensive and has less burden on the environment. Such a polymerization method is carried out using, for example, various monomers, initiator compounds, catalysts, radical polymerization initiators, and polymerization solvents described above.

で表されるヨウ素化合物を用いることが好ましい。(starting compound)
As a starting compound, the following formula 4

It is preferable to use an iodine compound represented by.

The iodine atom in such starting compounds is bound to a secondary or tertiary carbon atom, and X, Y and Z may be the same or different, hydrogen, hydrocarbon groups, halogen groups, cyano groups, It is preferably selected from alkoxycarbonyl, aryloxycarbonyl, acyloxy, allyloxy, alkoxy, alkylcarbonyl and allylcarbonyl groups.

Considering the dissociation of iodine, the iodine atom is preferably bonded to a secondary or tertiary carbon atom. As a result, at least two of X, Y and Z cannot be hydrogen atoms. Specific examples of X, Y and Z are given below, but are not limited thereto.

Hydrocarbon groups include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, and arylalkyl groups. Specifically, alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, 2-methylpropyl, t-butyl, pentyl, dodecyl; alkenyl groups containing a bond; alkynyl groups containing a triple bond such as acetylene, methylacetylene; aryl groups such as phenyl, naphthyl, methylphenyl, ethylphenyl, propylphenyl, dodecylphenyl, biphenyl, including pyridinyl, Aryl groups, which can also contain heterocycles such as imidazolinyl; arylalkyl groups such as phenylmethyl, 1-phenylethyl, 2-phenylethyl, 2-phenylpropyl; and the like.

A halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

Alkoxycarbonyl or aryloxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, propylcarbonyl, cyclohexylcarbonyl, benzyloxycarbonyl, phenoxycarbonyl, naphthoxycarbonyl and the like.

Acyloxy or aryloxy groups include acetoxy, ethylcarbonyloxy, cyclohexylcarbonyloxy, benzoyloxy, naphthylcarboxyoxy and the like.

Alkoxy groups include methoxy, ethoxy, methoxyethoxy, phenoxyethoxy, and the like.

Alkylcarbonyl or allylcarbonyl groups include methylcarbonyl, ethylcarbonyl, phenylcarbonyl and the like.

Preferred specific examples of starting compounds include 1-iodo-1-phenylethane, 2-iodo-2-cyanopropane, 2-iodo-2-cyano-4-methylpentane and the like.

Also, in such polymerization methods, the molecular weight of the copolymer can be controlled by the amount of the starting compound. By setting the number of moles of the monomer with respect to the number of moles of the starting compound, it is possible to control the desired molecular weight or the size of the molecular weight. The molar ratio between the starting compound and the monomer is not particularly limited, and can be appropriately determined according to the required molecular weight and the like. For example, 500 moles of a monomer with a molecular weight of 100 can be polymerized using 1 mole of the starting compound to provide a theoretical molecular weight of 1 x 100 x 500 = 50,000.

(catalyst)
As the catalyst, iodine in the starting compound or a non-metallic compound that becomes a radical capable of abstracting iodine at the terminal of the polymer, such as a phosphorus compound, a nitrogen compound, or an oxygen compound having such properties can be used.

Examples of phosphorus compounds include, but are not limited to, phosphorus halides containing iodine atoms, phosphite compounds, phosphinate compounds, and the like. Nitrogen compounds include imide compounds, hydantoins, Barbituric acids, cyanuric acids, etc., and oxygen compounds include phenolic compounds, iodooxyphenyl compounds, vitamins, and the like. These can be used alone or in combination of two or more.

Specifically, phosphorus compounds include phosphorus halides containing iodine atoms, phosphite compounds, and phosphinate compounds, such as dichloroiodrine, dibromoiodrine, phosphorus triiodide, dimethylphosphite, Diethylphosphite, dibutylphosphite, di(perfluoroethyl)phosphinate, diphenylphosphite, dibenzylphosphite, bis(2-ethylhexyl)phosphite, bis(2,2,2-trifluoroethyl)phosphite , diallyl phosphite, ethylene phosphite, ethyl phenyl phosphinate, phenyl phenyl phosphinate, ethyl methyl phosphinate, phenyl methyl phosphinate and the like.

Examples of nitrogen compounds include imides such as succinimide, 2,2-dimethylsuccinimide, α,α-dimethyl-β-methylsuccinimide, 3-ethyl-3-methyl-2,5-pyrrolidinedione, cis-1, 2,3,6-tetrahydrophthalimide, α-methyl-α-propylsuccinimide, 5-methylhexahydroisoindole-1,3-dione, 2-phenylsuccinimide, α-methyl-α-phenylsuccinimide, 2,3- diacetoxysuccinimide, maleimide, phthalimide, 4-methylphthalimide, N-chlorophthalimide, N-bromophthalimide, N-bromophthalimide, 4-nitrophthalimide, 2,3-naphthalenecarboximide, pyromellitic diimide, 5-bromoisoindole -1,3-dione, N-chlorosuccinimide, N-bromosuccinimide, N-iodosuccinimide and the like. Hydantoins include hydantoin, 1-methylhydantoin, 5,5-dimethylhydantoin, 5-phenylhydantoin, 1,3-diaiodo-5,5-dimethylhydantoin and the like. Barbituric acids include barbituric acid, 5-methylbarbituric acid, 5,5-diethylbarbituric acid, 5-isopropylbarbituric acid, 5,5-dibutylbarbituric acid, thiobarbituric acid, and the like. Cyanuric acids include cyanuric acid, N-methylcyanuric acid, triiodocyanuric acid and the like.

Examples of oxygen compounds include phenolic compounds that are phenolic hydroxyl groups having a hydroxyl group in an aromatic ring, iodooxyphenyl compounds that are iodides of phenolic hydroxyl groups, and vitamins. Examples of phenols include phenol, hydroquinone, 4-methoxyphenol, 4-t-butylphenol, 4-t-butyl-2-methylphenol, 2-t-butyl-4-methylphenol, catechol, resorcinol, 2,6-di-t-butyl-4-methyl Polymers obtained by polymerizing phenol, 2,6-dimethylphenol, 2,4,6-trimethylphenol, 2,6-di-t-butyl-4-methoxyphenol, 4-hydroxystyrene, or polymer fine particles supporting hydroxyphenyl groups thereof, Examples thereof include monomers having a phenolic hydroxyl group such as 3,5-di-t-butyl-4-hydroxyphenylethyl methacrylate. Since these are added to the ethylenically unsaturated monomers as polymerization inhibitors, the effects can also be exhibited by using the commercially available ethylenically unsaturated monomers as they are without purification. The iodooxyphenyl compounds include thymol iodide and the like, and the vitamins include vitamin C, vitamin E and the like.

The amount of the catalyst used is generally less than the number of moles of the radical polymerization initiator, and can be arbitrarily determined in consideration of the polymerization control state and the like.

(Radical polymerization initiator)
As the radical polymerization initiator, conventionally known ones can be used without particular limitation, but for example, organic peroxides or azo compounds can be used. Specifically, benzoyl peroxide, dicumyl peroxide, diisopropyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, t-butyl peroxy-2-ethylhexanoate , t-hexylperoxy-2-ethylhexanoate, 1,1-bis(t-butylperoxy) 3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-bis(t-butyl peroxy)hexyl-3,3-isopropyl hydroperoxide, t-butyl hydroperoxide, dicumyl hydroperoxide, acetyl peroxide, bis(4-t-butylcyclohexyl) peroxydicarbonate, isobutyl peroxide, 3 , 3,5-trimethylhexanoyl peroxide, lauryl peroxide, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)3, 3,5-trimethylcyclohexane, 2,2′-azobis(isobutyronitrile), 2,2′-azobis(2,4-dimethylvaleronitrile), 2,2′-azobis(4-methoxy-2,4 -dimethylvaleronitrile), dimethyl 2,2'-azobis(isobutyrate), and the like.

From the viewpoint of polymerizability, etc., the radical polymerization initiator can be used in the range of 0.001 mol times or more, 0.002 mol times or more, or 0.005 mol times or more with respect to the number of moles of the monomer, Moreover, it can be used in the range of 0.1 mol times or less, 0.05 mol times or less, or 0.01 mol times or less.

(Polymerization solvent)
As the polymerization solvent, a solvent that does not exhibit reactivity with the functional groups of the monomers is appropriately selected. Hydrocarbon solvents such as, but not limited to, hexane, octane, decane, isodecane, cyclohexane, methylcyclohexane, toluene, xylene, ethylbenzene, cumene; methanol, ethanol, propanol, isopropanol, butanol, isobutanol, Alcohol solvents such as hexanol, benzyl alcohol, cyclohexanol; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol propyl ether, butyl Hydroxyl group-containing glycol ethers such as carbitol, butyltriethylene glycol and methyldipropylene glycol; glycol solvents such as diglyme, triglyme, methyl cellosolve acetate, propylene glycol monomethyl ether acetate, dipropylene glycol butyl ether acetate and diethylene glycol monobutyl ether acetate; diethyl Ether solvents such as ether, dimethyl ether, dipropyl ether, methyl cyclopropyl ether, tetrahydrofuran, dioxane, and anisole; ketone solvents such as dimethyl ketone, diethyl ketone, ethyl methyl ketone, isobutyl methyl ketone, cyclohexanone, isophorone, and acetophenone; acetic acid ester solvents such as methyl, ethyl acetate, butyl acetate, propyl acetate, methyl butyrate, ethyl butyrate, caprolactone, methyl lactate, ethyl lactate; halogen solvents such as chloroform, dichloromethane, dichloroethane, o-dichlorobenzene; Amide solvents such as N-dimethylformamide, N,N-dimethylacetamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, ε-caprolactam; dimethylsulfoxide, sulfolane, tetramethylurea, ethylene carbonate, propylene carbonate, dimethyl carbonate , diethyl carbonate, nitromethane, acetonitrile, nitrobenzene, dioctyl phthalate, and the like.

(polymerization temperature)
The polymerization temperature is appropriately adjusted depending on the half-life of the radical polymerization initiator, and is not particularly limited. .

(polymerization time)
The polymerization time is preferably continued until the monomer disappears, and is not particularly limited. For example, it can be 0.5 hours or more, 1 hour or more, or 2 hours or more, and can be 48 hours or less and 24 hours or less. Or it can be 12 hours or less.

(Polymerization atmosphere)
The polymerization atmosphere is not particularly limited, and the polymerization may be carried out as it is under an air atmosphere. You can do it under ambient conditions. Impurities may be removed from the various materials used by distillation, activated carbon, alumina, or the like, but commercially available products may be used as they are. Moreover, the polymerization may be carried out under light shielding, or may be carried out in a transparent container such as glass.

《Applications of block copolymers》
The block copolymer of the present invention can be used, for example, as a surface treatment agent. The surface treatment of an object with the block copolymer of the present invention may be carried out using a normal treatment method, and the method is not particularly limited. For example, the block copolymer of the present invention is dissolved in a suitable dispersion medium, and the object is mixed and stirred in this solution to obtain a dispersion containing the surface-treated object. The surface-treated object may be used in the form of a dispersion, or may be used in the form of a dried powder.

When the block copolymer of the present invention is applied to an object as a surface treatment agent, the ratio of the object and the block copolymer is not particularly limited as long as the desired performance such as dispersibility is exhibited. :5 to 100:40, preferably 100:7 to 100:30, more preferably 100:10 to 100:20.

In addition, the content of the target substance in the dispersion can be in the range of 10% by mass or more, 20% by mass or more, or 30% by mass or more of the entire dispersion, and 90% by mass or less and 80% by mass. or less or 70% by mass or less.

<Object>
Objects to which the block copolymer of the present invention can be applied are not particularly limited, and can be used alone or in combination of two or more. inorganic particles, such as metal oxides, are preferred. Such hydroxyl groups on the surface of the object can form hydrogen bonds and the like with hydroxyl groups on the hydrophilic segment. Such inorganic particles are not particularly limited. Particles of zinc, titanium oxide, cerium oxide, aluminum oxide, calcium sulfate, barium sulfate, magnesium sulfate, calcium carbonate, magnesium carbonate, iron oxide, ultramarine blue, Prussian blue, chromium oxide, chromium hydroxide, carbon black, and composites thereof is mentioned. As for the shape of the particles, any shape can be used, for example, plate-like, block-like, scale-like, spherical, porous spherical, etc., and the particle size is not particularly limited.

(dispersion medium)
As the dispersion medium, organic solvents, particularly various oils, can be used, including, but not limited to, hydrocarbons such as liquid paraffin, squalane, isoparaffin, branched light paraffin, petroleum jelly, and ceresin. oils, ester oils such as isopropyl myristate, cetylisooctanoate, and glyceryl trioctanoate; and silicone oils such as decamethylpentasiloxane, dimethylpolysiloxane, and methylphenylpolysiloxane. These can be used alone or in combination of two or more.

Among them, silicone oil is preferably used from the viewpoint of the feeling of use when it is used as a cosmetic or the like. Specifically, silicone oil can be used in a range of 10% by mass or more, 50% by mass or more, or 70% by mass or more, and 100% by mass or less with respect to the entire dispersion medium. can be done.

Examples of silicone oils that can be used include, but are not limited to, chain polysiloxanes, cyclic polysiloxanes, modified silicones, and silicone resins. is preferred. For example, linear polysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, and methylhydrogenpolysiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, tetramethyltetrahydrogencyclotetrasiloxane, etc. and the like.

Among them, volatile chain polysiloxanes such as low polymerization degree dimethylpolysiloxane (polymerization degree 3 to 7), and volatile silicone oils such as cyclic volatile polysiloxanes such as decamethylcyclopentasiloxane and octamethylcyclotetrasiloxane. When used, for example, when it is applied to the skin as a cosmetic or the like, an oily feeling does not easily remain, and a refreshing feeling of use is obtained, which is particularly suitable.

<<Application of Inorganic Particle Dispersion>>
The dispersion of inorganic particles surface-treated with the block copolymer of the present invention can significantly suppress the increase in viscosity associated with the addition of inorganic particles compared to the inorganic particle dispersion system by conventional surface treatment, so the formulation is limited. Inorganic particles can be highly incorporated without Therefore, such a dispersion can be used in various applications such as cosmetics, resin compositions, paints, inks, and coating compositions. preferably. Although not intended to limit the present invention, a cosmetic using a dispersion of inorganic particles surface-treated with the block copolymer of the present invention will be specifically described below.

<Cosmetics>
When the inorganic particle dispersion of the present invention is applied to cosmetics, it can be used as it is or diluted with an oily component to prepare an oily type cosmetic. It can also be an oil-in-water or water-in-oil emulsified cosmetic, particularly an oil-in-water emulsified cosmetic.

Cosmetics containing the inorganic particle dispersion of the present invention, particularly sunscreen cosmetics, contain UV scattering agents such as titanium oxide, zinc oxide, cerium oxide, iron oxide, and mica with dispersibility without significantly increasing the viscosity. It can often be highly formulated in cosmetics. As a result, such a cosmetic has excellent applicability to the skin and can increase the SPF value based on the UV scattering and shielding effects of the uniformly dispersed scattering agent.

Since the SPF value is a numerical value that varies depending on the degree of dispersion of inorganic particles, the SPF value can also be used as an index of dispersion stability. The SPF value and viscosity of the cosmetic are not limited to the following, but for example, the SPF value can be 15 or more, 20 or more, or 25 or more, and 60 or less, 55 or less, or 50 or less. and the viscosity can be 50000 Pa s or less, 30000 Pa s or less, or 10000 Pa s or less, particularly 3000 Pa s or less, 2800 Pa s or less, or 2500 Pa s or less. The viscosity can also be low, and can be 100 Pa·s or more, 150 Pa·s or more, or 200 Pa·s or more. Here, the viscosity is measured at 32 ° C. and 1 atm using VDA-2 or VS-H1 (both manufactured by Shibaura Systems Co., Ltd.) as a Vistometholon viscometer. Intended viscosity at time.

The inorganic particle dispersion of the present invention can be highly blended with the inorganic particles in the cosmetic, and is not limited to the following. On the other hand, 5% by mass or more, 10% by mass or more, or 15% by mass or more can be blended, and 50% by mass or less, 48% by mass or less, or 45% by mass or less can be blended.

The cosmetic composition of the present invention can be in any dosage form, and can be provided in any form such as solution system, solubilization system, emulsification system, water-oil two-layer system, gel, aerosol, mist, and capsule. In addition, the product form of the cosmetic of the present invention is also arbitrary, and facial cosmetics such as lotions, milky lotions, creams, packs; makeup cosmetics such as screens; body cosmetics; aromatic cosmetics; skin cleansers such as makeup removers, facial cleansers and body shampoos; It can be applied in any form as long as it is used for external preparations for skin. In particular, it is suitably used as a product for the purpose of UV protection.

(Optional component)
The cosmetic of the present invention can contain various components as appropriate within a range that does not affect the effects of the present invention. Examples of various components include additive components that can be usually blended in cosmetics, such as liquid fats and oils, solid fats and oils, waxes, oils such as higher fatty acids, higher alcohols, anionic surfactants, cationic surfactants, and amphoteric surfactants. , nonionic surfactants, moisturizers, water-soluble polymers, thickeners, film agents, sequestering agents, lower alcohols, polyhydric alcohols, extracts, sugars, amino acids, organic amines, polymer emulsions, chelates agents, UV absorbers, pH adjusters, skin nutrients, vitamins, pharmaceuticals, quasi-drugs, water-soluble agents applicable to cosmetics, antioxidants, buffers, preservatives, antioxidant aids, organic Examples include powders, pigments, dyes, dyes, fragrances, water, and the like.

When used as a sunscreen cosmetic, one or two or more water-soluble or oil-soluble organic UV absorbers may be blended.

Examples of water-soluble ultraviolet absorbers include 2,4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2′,4 , 4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone , 2-ethylhexyl-4'-phenyl-benzophenone-2-carboxylate, 2-hydroxy-4-n-octoxybenzophenone, 4-hydroxy-3-carboxybenzophenone and other benzophenone UV absorbers, phenylbenzimidazole-5 - benzimidazole UV absorbers such as sulfonic acid and its salts, phenylene-bis-benzimidazole-tetrasulfonic acid and its salts, 3-(4'-methylbenzylidene)-d,l-camphor, 3-benzylidene-d , l-camphor, urocanic acid, urocanic acid ethyl ester and the like.

Examples of oil-soluble ultraviolet absorbers include para-aminobenzoic acid (PABA), PABA monoglycerol ester, N,N-dipropoxy PABA ethyl ester, N,N-diethoxy PABA ethyl ester, N,N-dimethyl PABA ethyl ester, N , N-dimethyl PABA butyl ester and other benzoic acid UV absorbers; homomenthyl-N-acetylanthranilate and other anthranilic acid UV absorbers; amyl salicylate, menthyl salicylate, homomenthyl salicylate, octyl salicylate, phenyl salicylate, benzyl Salicylic acid-based UV absorbers such as salicylate and p-isopropanol phenyl salicylate; octyl cinnamate, ethyl-4-isopropyl cinnamate, methyl-2,5-diisopropyl cinnamate, ethyl-2,4-diisopropyl cinnamate, methyl-2 , 4-diisopropylcinnamate, propyl-p-methoxycinnamate, isopropyl-p-methoxycinnamate, isoamyl-p-methoxycinnamate, octyl-p-methoxycinnamate, 2-ethylhexyl-p-methoxycinnamate, 2 -ethoxyethyl-p-methoxycinnamate, cyclohexyl-p-methoxycinnamate, ethyl-α-cyano-β-phenylcinnamate, 2-ethylhexyl-α-cyano-β-phenylcinnamate, glyceryl mono-2-ethyl Cinnamic acid-based UV absorbers such as hexanoyl-diparamethoxycinnamate, 3,4,5-trimethoxycinnamate 3-methyl-4-[methylbis(trimethylsiloxy)silyl]butyl; 2-phenyl- 5-methylbenzoxazole, 2,2'-hydroxy-5-methylphenylbenzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2-(2'-hydroxy-5' -methylphenylbenzotriazole, dibenzalazine, dianisoylmethane, 4-methoxy-4'-t-butyldibenzoylmethane, 5-(3,3-dimethyl-2-norbornylidene)-3-pentan-2-one, octocrylene, etc. is mentioned.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these. Hereinafter, unless otherwise specified, the compounding amount is shown in parts by mass.

<<Examples 1 to 5 and Comparative Examples 1 to 8>>

<Method for synthesizing copolymer>
(Copolymer 1)
30 parts by mass of propylene glycol monomethyl ether acetate, 110 parts by mass of a monomer of the following formula 2, 0.25 parts by mass of iodine, 2,2'-azobis ( 0.3 parts by mass of isobutyronitrile) was charged and polymerized at 80° C. for 2 hours while bubbling nitrogen to prepare a hydrophobic segment.

式２中、Ｒ^１及びＲ^２はメチル基であり、Ｒ^３はブチル基であり、ｍは３であり、かつ、ｎは１０である。

In Formula 2, R ¹ and R ² are methyl groups, R ³ is a butyl group, m is 3, and n is 10.

Subsequently, 15 parts by mass of methacrylic acid was added and polymerized at the same temperature for 2 hours to form a hydrophilic block portion, thereby obtaining a block copolymer having a hydrophobic segment and a hydrophilic segment. When the molar ratio of the obtained block copolymer is converted from the amount of each monomer raw material used, the ratio of the monomer units of formula 2 is about 80.5 mol%, and the ratio of the methacrylic acid monomer units is about 19.5% by mole. It was 5 mol %.

(Copolymer 2)
A block copolymer of Copolymer 2 was produced in the same manner as Copolymer 1, except that n of the monomer of Formula 2 was changed from 10 to 30.

(Copolymer 3)
A block copolymer of Copolymer 3 was produced in the same manner as Copolymer 1, except that 80 parts by mass of a monomer of Formula 1 below was used instead of the monomer of Formula 2 above.

式１中、Ｒ^１はメチル基であり、かつｍは１１である。

In Formula 1, R ¹ is a methyl group and m is 11.

(Copolymer 4)
A block copolymer of copolymer 4 was prepared in the same manner as for copolymer 1, except that methyl methacrylate was used instead of the monomer of formula 2 above.

<Method for preparing surface-treated inorganic particle dispersion>
(Dispersion 1)
20 g of copolymer 1 was dissolved in 200 g of butyl diglycol, then 80 g of titanium oxide (ST-485WD, manufactured by Titan Kogyo Co., Ltd.) was added to this solution and stirred at room temperature for 1 hour. , a titanium oxide dispersion liquid 1 containing 50% by mass of surface-treated titanium oxide was prepared.

(Dispersions 2 to 4)
Dispersions 2 to 4 of titanium oxide were prepared in the same manner as dispersion 1, except that copolymers 2 to 4 were used instead of copolymer 1, respectively.

<Evaluation of viscosity and SPF value>
Emulsions obtained by the formulations and production methods shown in Tables 1 and 2 below were evaluated for viscosity and SPF value, also called UV protection factor. Here, the viscosity is measured at 32 ° C. and 1 atm using VDA-2 for low viscosity and VS-H1 for high viscosity as a Vistometholon viscometer, and the shear rate of the object to be measured is 1 /s hour viscosity was adopted. In addition, the SPF value is obtained by applying the obtained emulsion on a transparent tape at a coating amount of 2 mg / cm ² to obtain an evaluation sample, and the evaluation sample has a spectrum that is almost the same as that of sunlight in the ultraviolet region. The SPF value was calculated by inserting between a solar simulator manufactured by Solar Light Co., Ltd., which is a light source, and a spectrophotometer, and comparing spectra with and without an evaluation sample. The calculation method from each spectrum is the same as the method described in paragraph numbers "0076" and "0077" of JP-B-6-27064.

<Method for producing emulsions of Examples 1 to 2 and Comparative Examples 1 to 6>
(Example 1)
Cyclopentasiloxane, which is an oil component, and titanium oxide powder obtained by drying dispersion liquid 1 of titanium oxide were stirred and mixed at room temperature to prepare a mixture A. Next, the surfactant PEG-10 dimethicone and ion-exchanged water are stirred and mixed at 60 ° C. to prepare a mixture B, and while stirring at 60 ° C., the mixture A is added to the mixture B. An emulsion was produced. Table 1 summarizes the composition of the emulsion.

(Example 2)
An emulsion of Example 2 was prepared in the same manner as in Example 1, except that cyclopentasiloxane and cetylisooctanoate were used as the oil. Table 1 summarizes the composition of the emulsion.

(Comparative Examples 1 to 2, 4 and 5)
Comparative Examples 1 and 2, Comparative Examples 1 and 2, Emulsions 4 and 5 were made respectively. Table 1 summarizes the composition of the emulsion. Here, powder A in Table 1 is titanium oxide powder surface-treated with aluminum stearate, and dispersion liquid B is 40 mass of titanium oxide surface-treated with aluminum stearate in cyclopentasiloxane. % and 10% by weight of a surfactant, and dispersion C contains 40% by weight of titanium oxide surface-treated with hydrogen dimethicone in cyclopentasiloxane and 10% by weight of a surfactant. dispersion.

(Comparative Examples 3 and 6)
Cyclopentasiloxane, which is an oil component, ion-exchanged water, and dispersion liquid B or dispersion liquid C were stirred and mixed at 60° C. to prepare emulsions of Comparative Examples 3 and 6, respectively. Table 1 summarizes the composition of the emulsion.

<result>
As is clear from Table 1, the emulsions of Comparative Examples 1 to 6, which employ titanium oxide surface-treated with materials commonly used in the past, have high viscosities of about 6700 Pa s or more. However, Examples 1 and 2, which employ titanium oxide surface-treated with the block copolymer of the present invention, have excellent dispersibility of titanium oxide, and are comparatively unstable. It was found that the viscosity of the emulsion can be significantly reduced compared to Examples 1-6. Further, for example, as can be seen from Comparative Examples 2 and 4, when titanium oxide surface-treated with a conventional material is used, the viscosity varies greatly depending on the type of oil content, but the emulsions of Examples 1 and 2 are , was found to be almost unaffected by the type of oil. Therefore, it was also found that an object such as titanium oxide surface-treated with the block copolymer of the present invention is not easily restricted by the type of oil.

<Method for producing emulsions of Examples 3 to 5 and Comparative Examples 7 to 8>
(Example 3)
Mixture C was prepared by stirring and mixing the oil content shown in Table 2 and the dry powder of Dispersion 2, which is a UV scattering agent, in an atmosphere of 80° C. at the blending ratio shown in Table 2. Next, water, alcohol, thickener, humectant, surfactant, UV absorber and other components listed in Table 2 were stirred and mixed at the mixing ratios listed in Table 2 under an atmosphere of 80°C. Mixture D was prepared by mixing the above ingredients, and mixture C was added to mixture D while stirring at 80° C. to prepare an emulsion of Example 3. Table 2 summarizes the composition of the emulsion.

(Examples 4 and 5)
Emulsions of Examples 4 and 5 were prepared in the same manner as in Example 3, except that the UV scattering agent was changed from the dry powder of Dispersion 2 to the dry powder of Dispersion 3 or the dry powder of Dispersion 4. bottom. Table 2 summarizes the composition of the emulsion.

(Comparative Example 7)
Water, alcohol, thickener, humectant, oil, surfactant, UV absorber and other components listed in Table 2 were stirred and mixed in an atmosphere at 80°C in the proportions listed in Table 2. An emulsion of Comparative Example 7 was prepared by Table 2 summarizes the composition of the emulsion.

(Comparative Example 8)
An emulsion of Comparative Example 8 was prepared in the same manner as in Example 3, except that the UV scattering agent was changed from the dry powder of Dispersion 2 to Powder A. Table 2 summarizes the composition of the emulsion.

<result>
As is apparent from Table 2, when a portion of the UV absorber in Comparative Example 7, which does not contain a UV scattering agent, is replaced with a UV scattering agent, the viscosity generally decreases as shown in Comparative Example 8. In addition, the SPF value tends to decrease due to the deterioration of the dispersibility of the UV scattering agent. On the other hand, in the case of Examples 3 to 5, in which the titanium oxide surface-treated with the block copolymer of the present invention was adopted, even if a part of the UV absorber was replaced with the UV scattering agent, the viscosity did not increase. It has been found that the viscosity can be reduced and also the SPF value can be increased.

In addition, from the results of Comparative Example 7 and Examples 3 to 5 in Table 2, when using a UV scattering agent containing titanium oxide or the like surface-treated with the block copolymer of the present invention, a UV scattering agent such as shown in Comparative Example 7 Since it is possible to obtain an SPF value equal to or higher than that of a system that does not contain the It can be easily presumed that the SPF value can be further increased.

1 hydrophobic segment 2 hydrophilic segment 3 object

Claims (3)

A block copolymer comprising a hydrophobic segment and a hydrophilic segment,
The hydrophobic segment comprises a monomer unit composed of at least one monomer selected from the following formulas 1 and 2,
wherein the hydrophilic segment comprises a monomer unit composed of a monomer of formula 3 below,
block copolymers , and
comprising inorganic particles surface-treated with the block copolymer;
Cosmetics :

In formula 1,
R ¹ is hydrogen or a methyl group, and m is an integer from 0 to 21,

In formula 2,
R ¹ is hydrogen or a methyl group,
R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms,
m is an integer from 1 to 6, and n is an integer from 5 to 70,

In formula 3,
R ¹ is hydrogen or a methyl group. R ¹ in Formula 1 is a methyl group, m is an integer of 10 to 15,
R ¹ and R ² in formula 2 are methyl groups, R ³ is a butyl group, m is an integer of 1 to 3, n is an integer of 10 to 60, and the formula 2. Cosmetics according to claim 1, wherein R ¹ of 3 is a methyl group. 3. The cosmetic according to claim 1, wherein the proportion of said hydrophobic segment is 50 to 99 mol % and the proportion of said hydrophilic segment is 1 to 50 mol %.

Images