JP5329241B2 - Crosslinked polymer and method for producing crosslinked polymer - Google Patents

Abstract

Disclosed is a crosslinked polymer with an interlocked structure, wherein a polymer with two or more ring portions is mixed with a straight-chain molecule with a block group at one end and a polymerizable functional group at the other end and/or a straight-chain molecule with polymerizable functional groups at both ends, causing inclusion complexes to form in all or some thereof, and then copolymerizing the aforementioned polymerizable functional group(s) with a water-soluble (meth)acrylic acid-based monomer that does not have a minimum critical solution temperature. This crosslinked polymer can be easily produced and yield a clean film.

Description

  The present invention relates to a crosslinked polymer containing a rotaxane structure and a method for producing the same.

  Patent Document 1 discloses a crosslinked polymer (polymer gel) containing a rotaxane structure in which a polydrotaxane using cyclodextrin as a cyclic molecule and polyethylene glycol as a linear molecule included in the cyclic molecule is crosslinked. ing.

  Unlike conventional physical gels or chemical gels, this polymer gel is composed of mechanical bonds (interlock structure) that do not use both non-covalent bonds and covalent bonds, and cyclic molecules are linear molecules. Because it can move freely, it can exhibit unprecedented flexibility.

Japanese Patent No. 3475252

  In order to produce the above polymer gel, a pseudo polyrotaxane is synthesized and isolated, the pseudo polyrotaxane is dissolved again in another solvent, and then the end is capped with a capping agent to obtain a polyrotaxane, and again, It was necessary to isolate and purify and to crosslink the cyclodextrin part of the polyrotaxane with the action of a crosslinking agent. In view of industrialization, such a multistage reaction is very disadvantageous from the viewpoint of production cost, and the yield of each stage has never been high.

  For these reasons, there has been a strong demand for a method that can more easily produce a crosslinked polymer (polymer gel) having an interlock structure. Furthermore, it has been strongly desired to obtain a crosslinked polymer (polymer gel) having an interlock structure as a beautiful film when, for example, it is applied to optical materials and the like.

  The present invention has been made in view of such a situation, and a crosslinked polymer having an interlock structure that can be easily produced and a method for producing the crosslinked polymer, and in particular, a beautiful crosslinked polymer in a film and a method for producing the crosslinked polymer. The purpose is to provide.

  In order to achieve the above object, first, the present invention comprises a polymer having two or more cyclic moieties, a linear molecule having a blocking group at one end and a polymerizable functional group at the other end, and / Or mixed with a linear molecule having a polymerizable functional group at both ends, to form an inclusion complex for all or a part thereof, then, the polymerizable functional group of the linear molecule and the lower critical solution Provided is a method for producing a crosslinked polymer, which comprises copolymerizing a water-soluble (meth) acrylic acid monomer having no temperature (Invention 1).

  Second, the present invention relates to a polymer having two or more cyclic moieties and a linear chain capable of forming an inclusion complex with the polymer having a blocking group at one end and a polymerizable functional group at the other end. Polymerization of the linear molecule of the polymer cross-linking precursor obtained by mixing the polymer and a linear molecule capable of forming an inclusion complex, having a polymerizable molecule and / or a polymerizable functional group at both ends Provided is a crosslinked polymer obtained by copolymerizing a functional group and a water-soluble (meth) acrylic acid monomer having no lower critical solution temperature (Invention 2).

  In the above invention (Invention 2), the cyclic portion of the polymer is at least one selected from the group consisting of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin, or cyclic polyether, cyclic polyester, and cyclic polyether. It is preferably at least one selected from the group consisting of amines and cyclic polyamines (Invention 3).

  According to the present invention, a crosslinked polymer having an interlock structure can be easily and efficiently produced. Further, according to the present invention, a crosslinked polymer having an interlock structure can be produced with good film forming properties. When a polymer crosslinked body is obtained as a film, the polymer crosslinked body has both film strength and stretchability, and is excellent in film forming properties, so that a beautiful film having high surface smoothness is obtained.

It is a schematic diagram which shows the manufacturing process of the polymer crosslinked body which concerns on one Embodiment of this invention. It is a schematic diagram which shows the manufacturing process of the polymer crosslinked body which concerns on other embodiment of this invention. It is a figure explaining the manufacturing method of the gel-like film of a polymeric bridge | crosslinking body (E) in an Example.

Hereinafter, embodiments of the present invention will be described.
The crosslinked polymer (E) according to one embodiment of the present invention can be produced by the method schematically shown in FIG. 1 or FIG.

  First, a polymer having two or more cyclic moieties (hereinafter referred to as “polymer (A)”) and a linear molecule having a blocking group at one end and a polymerizable functional group at the other end (hereinafter referred to as “polymer (A)”) ("Linear molecule (B1)") and / or a linear molecule having a polymerizable functional group at both ends (hereinafter referred to as "Linear molecule (B2)") (see FIG. 1). (See FIG. 2). The linear molecule (B1) and the linear molecule (B2) are collectively referred to as “linear molecule (B)”.

  The cyclic portion of the polymer (A) can include the linear molecule (B) and can move on the linear molecule (B) in that state. In the present specification, “cyclic” of the “cyclic portion” means substantially “cyclic”, and if the cyclic portion is movable on the linear molecule (B), the cyclic portion is completely May not be closed, for example, may have a helical structure. Further, the polymer (A) of the present invention is a multimer having a cyclic molecule having a relatively large molecular weight as a constituent part as described later, and its own molecular weight becomes enormous even if the number of repetitions is small. The polymer (A) of the present invention is a name used for this purpose for convenience, and includes those having a repeating number of oligomer regions of about 2 to 10 mer.

  The molecules constituting the cyclic part (cyclic molecules) include cyclodextrins such as α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, or cyclic polyethers, cyclic polyesters, cyclic polyetheramines, cyclic polyamines, cyclo A fan or the like is preferable, and two or more kinds of these cyclic molecules may be mixed in the polymer (A) or the polymer crosslinked precursor (C) or the polymer crosslinked product (E) described later.

  When the cyclic molecule is a cyclodextrin, a polymer chain and / or a substituent that can improve the solubility of the polymer (A) in the linear molecule (B) is introduced into the hydroxyl group of the cyclodextrin. It may be. Examples of such a polymer chain include an oxyethylene chain, an alkyl chain, and an acrylate chain. On the other hand, examples of the substituent include an acetyl group, an alkyl group, a trityl group, a tosyl group, a trimethylsilane group, and a phenyl group.

  Specific examples of the cyclic molecule other than cyclodextrin include crown ether or derivatives thereof, cyclic lactone or derivatives thereof, calixarene or derivatives thereof, azacyclophane or derivatives thereof, thiacyclophane or derivatives thereof, cryptand or derivatives thereof, etc. Is mentioned.

  As the cyclic molecule, α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, and crown ether are preferable because linear molecules are easy to penetrate in a skewered manner. Α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin are particularly preferable because they form a complex.

  The number of cyclic molecules in the polymer (A) is 2 or more, preferably 3 to 50, particularly preferably 3 to 5. By having two or more cyclic molecules, a plurality of linear molecules (B) can thereby be included, and the linear molecules (B) are polymerized by polymerizing the linear molecules (B). A plurality of (co) polymers included in the structural unit are bonded to each other via the polymer (A) to form a crosslinked structure. Three or more cyclic molecules are more preferable because the cross-linked structure becomes dense and the strength can be improved without impairing the stress relaxation property of the resulting polymer cross-linked product (E).

  The structure of the polymer (A) is preferably a structure in which two or more cyclic molecules are linked by a linking moiety. The raw material compound (linking molecule) serving as the linking moiety is preferably a molecule that does not form or is difficult to form an inclusion complex with a cyclic molecule. By using such a linking molecule, when the polymer (A) is synthesized, the cyclic molecule can be linked without closing the opening of the cyclic molecule.

  Such a linking molecule may be linear or branched, but preferably has a side chain that is somewhat bulky. For example, when the cyclic moiety is α-cyclodextrin, it preferably has a side chain that is bulkier than a methyl group. That is, from the viewpoint of not forming an inclusion complex with the cyclic moiety, examples of a preferable linking moiety include polypropylene glycol, polyacrylic acid ester, polydimethylsiloxane, polyisoprene and the like, and polypropylene glycol is particularly preferable.

  The number average molecular weight (Mn) of one linking molecule is preferably 100 to 100,000, and more preferably 500 to 10,000. If the number average molecular weight of the linking molecule is less than 100, the openings of the cyclic molecules of the formed polymer (A) are too close to each other so that it is difficult to form a cross-linked structure and the effect based on the interlock structure is sufficiently exerted. There is a risk that it will not be. On the other hand, if the number average molecular weight of the linking molecule exceeds 100,000, the compatibility with the linear molecule (B) or the like may be deteriorated and it may be difficult to form a crosslinked structure.

  The mass average molecular weight (Mw) of the polymer (A) depends on the kind of the cyclic molecule, but is usually preferably 1,000 to 1,000,000, particularly 3,000 to 100,000. It is preferable. When the weight average molecular weight of the polymer (A) is less than 1,000, the number of cyclic portions is often less than 2, and there is a possibility that an interlock structure cannot be formed. Since the parts are very close to each other, the effect based on the interlock structure may not be sufficiently exhibited. On the other hand, when the mass average molecular weight of the polymer (A) exceeds 1,000,000, the compatibility with the linear molecule (B) or the like may be deteriorated and it may be difficult to form a crosslinked structure.

  The polymer (A) can be synthesized by a conventional method. For example, the polymer (A) is obtained by reacting a cyclic molecule having a functional group with a linking molecule having a reactive group capable of reacting with the functional group of the cyclic molecule at the terminal. Specifically, when synthesizing a polymer (A) in which the cyclic molecule is α-cyclodextrin and the linking molecule is polypropylene glycol, α-cyclodextrin and polypropylene glycol having a reactive group at the terminal are mixed. The polymer (A) can be obtained by adding a catalyst if desired and reacting both.

  As the functional group of the cyclic molecule bonded to the linking molecule, for example, a hydroxyl group, a carboxyl group, an amino group, a thiol group and the like are preferable, and as the reactive group at the terminal of the linking molecule, for example, an isocyanate group, an epoxy group, an aziridine Groups and the like are preferred. Examples of the linking molecule include isocyanate compounds such as xylylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, isophorone diisocyanate, and epoxy compounds such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and 1,6-hexanediol glycidyl ether. A compound having an aziridine compound such as N, N-hexamethylene-1,6-bis (1-aziridinecarboxyamide) at the terminal can be used.

  The linear molecule (B) is a linear molecule or substance that is included in the cyclic molecule of the polymer (A) and can be integrated by a mechanical bond rather than a chemical bond such as a covalent bond. And having a blocking group at one end and a polymerizable functional group at the other end (linear molecule (B1)), or having a polymerizable functional group at both ends (linear molecule ( B2)). In the present specification, “linear” of “linear molecule” means substantially “linear”. That is, as long as the cyclic part of the polymer (A) can move on the linear molecule (B), the linear molecule (B) may have a branched chain.

  As a molecule constituting the portion (main body portion) excluding both ends (block group / polymerizable functional group) of the linear molecule (B), it penetrates through the opening of the cyclic molecule of the polymer (A). Any molecule that can be produced is acceptable. For example, when the cyclic molecule of the polymer (A) is α-cyclodextrin, polyethylene glycol, polytetrahydrofuran, polyethylene, polycaprolactone and the like are preferable, and a linear molecule (B) having a main body portion composed of these molecules. ) May be mixed in the polymer crosslinked precursor (C) or the polymer crosslinked body (E).

  The number average molecular weight (Mn) of the molecules constituting the main part of the linear molecule (B) is preferably 100 to 300,000, particularly preferably 200 to 200,000, and more preferably 300 to Preferably it is 100,000. When the number average molecular weight is less than 100, the amount of movement of the cyclic moiety on the linear molecule (B) becomes small, and the resulting polymer crosslinked product (E) does not have sufficient stretchability as a film. There is a fear. Moreover, when a number average molecular weight exceeds 300,000, there exists a possibility that the solubility to a solvent may worsen.

  The blocking group at one end of the linear molecule (B1) is a group that does not leave the cyclic portion of the polymer (A) that includes the linear molecule (B1) and can maintain the form of an inclusion complex. If it is, it will not be specifically limited. Examples of such groups include bulky groups and ionic groups.

  As the blocking group, for example, dialkylphenyl groups, dinitrophenyl groups, cyclodextrins, adamantane groups, trityl groups, fluoresceins, pyrenes, anthracenes and the like are preferable. Or 2 or more types may be mixed in the polymer crosslinked body. As a capping agent that binds to one end of the linear molecule (B1) to form a blocking group, for example, dimethylphenyl isocyanate, tritylphenyl isocyanate, 2,4-dinitrofluorobenzene, adamantaneamine and the like are preferably used. .

  The polymerizable functional group at the other end of the linear molecule (B1) and the polymerizable functional group at both ends of the linear molecule (B2) are linked with the linear molecule (B) via the polymerizable functional group. If it can copolymerize with the water-soluble (meth) acrylic-acid type monomer (D) which does not have the lower critical solution temperature mentioned later, it will not specifically limit. As such a polymerizable functional group, for example, (meth) acryloyl group, vinyl group, epoxy group, acetylene group, oxetanyl group and the like are preferable.

  The linear molecule (B1) can be synthesized by a conventional method. For example, a linear molecule having a polymerizable functional group at one end, or a linear molecule having a different polymerizable functional group at both ends, and a capping agent for a blocking group are reacted, and one end is To obtain a linear molecule (B1) having a blocking group at one end and a polymerizable functional group at the other end by leaving the polymerizable functional group at the other end and adding a blocking group at the other end. Can do.

  As an example, a linear molecule having a hydroxyl group at one end and a (meth) acryloyl group at the other end and a dialkylphenyl compound having an isocyanate group are mixed, and if desired, a catalyst is added and both are reacted. Thus, a linear molecule (B1) having a dialkylphenyl group as a blocking group at one end and a (meth) acryloyl group as a polymerizable functional group at the other end is obtained.

  On the other hand, as the linear molecule (B2) having a polymerizable functional group at both ends, a commercially available one is used as it is, or, for example, a non-polymerizable functional group at both ends of the linear molecule is used as a polymerizable functional group. It can be obtained by substitution.

  As an example, a linear functional molecule having hydroxyl groups at both ends and a (meth) acryloyl compound having an isocyanate group are mixed, a catalyst is added if desired, and both are reacted, thereby allowing polymerizable functional groups at both ends. A linear molecule (B2) having a (meth) acryloyl group is obtained.

  When the polymer (A) and the linear molecule (B) described above are prepared, the polymer (A) and the linear molecule (B) are mixed to form an inclusion complex for all or part of the polymer (A) and the linear molecule (B). A polymer crosslinking precursor (C) is produced. That is, one opening portion of the annular portion of the polymer (A) is inserted in a skewered manner with the linear molecule (B), and at least one of the remaining openings of the annular portion of the polymer (A) is inserted. A polymer cross-linking precursor having a structure in which two or more linear molecules (B) are included in a plurality of cyclic parts of the same polymer (A), penetrating by another linear molecule (B) (C) is manufactured (see FIGS. 1 and 2).

  The polymer cross-linking precursor (C) is characterized in that it has a structure in which the above-mentioned inclusion complex is formed, but all the openings of the cyclic part of the polymer (A) are in such a state. You don't need to be. That is, in the polymer (A) as a mixture, a structure in which the linear molecule (B) is penetrated in only one of the openings of the cyclic part, and further, the cyclic part of the polymer (A) The opening may have a structure in which the linear molecule (B) is not penetrated in a skewered manner, or the linear molecule (B) as a mixture not included in the polymer (A) May be included.

  The polymer crosslinking precursor (C) as described above is prepared by mixing the polymer (A) and the linear molecule (B) in a solvent, for example, water, aqueous sodium hydroxide, dimethylformamide (DMF) and water. In a mixed solution of methanol and water (hereinafter sometimes referred to as “aqueous solvent”) (for example, the linear molecule (B) is added to the solution of the polymer (A)) And can be carried out by stirring the solution. The fact that the polymer crosslinking precursor (C) has been obtained can be judged by an increase in the viscosity of the solution.

  There is no restriction | limiting in particular about the stirring method, It can stir by methods, such as a mechanical stirring process and an ultrasonic treatment, at normal temperature or the temperature controlled appropriately, It is preferable to specifically stir by ultrasonic treatment. The stirring time is preferably performed under conditions of several minutes to 1 hour. Although there is no restriction | limiting in particular about the irradiation conditions of an ultrasonic wave, It is preferable to carry out with a frequency of 20-40 kHz.

  When the polymer cross-linking precursor (C) is produced as described above, the linear molecule is introduced via the polymerizable functional group of the linear molecule (B) included in the cyclic portion of the polymer (A). (B) and a water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature are copolymerized to obtain a crosslinked polymer (E) (see FIGS. 1 and 2). This crosslinked polymer (E) contains a rotaxane structure as an interlock structure. In addition, although N, N- dimethylacrylamide is illustrated as an example as a water-soluble (meth) acrylic-acid-type monomer (D) which does not have the minimum critical solution temperature in FIG. 1 and FIG. 2, it is limited to this. It is not something.

As shown in FIG. 1, the crosslinked polymer (E) when the linear molecule (B1) is used is specifically a water-soluble (meth) acrylic acid monomer having no lower critical solution temperature ( D) and copolymers BD ₁ and BD ₂ formed from linear molecules (B1) and a polymer Ax having two or more cyclic molecules. Then, the side chain Bx derived from the linear molecule (B1) of the copolymer BD ₁ passes through the opening of one cyclic molecule of the polymer Ax, and a structure that cannot escape due to the presence of the blocking group (rotaxane Structure). Further, a structure in which the side chain By derived from the linear molecule (B1) of the copolymer BD ₂ penetrates through an opening of another cyclic molecule of the polymer Ax and cannot be escaped due to the presence of a blocking group (rotaxane). Structure). Thus, it is the copolymer BD ₁ and copolymer BD ₂ via a polymer Ax mechanically coupled structure (interlocking structure). That is, the copolymers BD ₁ and BD ₂ have the polymer Ax as a cross-linked site, but since the site has mobility, the polymer cross-linked product (E) has stretchability.

  In addition, film strength will become strong, if there are many number of bridge | crosslinking parts. Therefore, in the present embodiment, by making the cross-linked sites movable while having a certain number of cross-linked sites to some extent, the film has a sufficient film strength when used as a film, but has a certain amount or more of impulse. When added, a crosslinked polymer (E) that can disperse force by stretching is obtained. The resulting polymer crosslinked product (E) is a novel substance.

In addition, as shown in FIG. 2, the crosslinked polymer (E) when the linear molecule (B2) is used is specifically a water-soluble (meth) acrylic acid type that does not have a lower critical solution temperature. Copolymer chains BD ₁ ′ and BD ₂ ′ formed from the monomer (D) and the linear molecule (B2) are cross-linked at the Bx ′ portion derived from the linear molecule (B2). Similarly, copolymer chains BD ₃ ′ and BD ₄ ′ formed from a water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature and a linear molecule (B2) are linear Is cross-linked at the By ′ portion derived from the molecular molecule (B2). Furthermore, the Bx ′ and By ′ portions form a conjugated complex with a different cyclic molecule of the polymer Ax ′ having a cyclic portion and have a structure that cannot escape (rotaxane structure). As a result, the copolymer consisting of the copolymer chains BD ₁ ′ and BD ₂ ′ and the copolymer consisting of the copolymer chains BD ₃ ′ and BD ₄ ′ are mechanically bonded via the polymer Ax ′. The resulting structure (interlock structure) is obtained. Thereby, a film having various physical properties similar to those of the crosslinked polymer (E) described in FIG. 1 can be obtained. 1 and 2 are illustrated for explaining the present embodiment, and the present invention is not limited thereby.

  In the present embodiment, a water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature is polymerized with the polymer crosslinking precursor (C) (the linear molecule (B) therein). Examples of water-soluble (meth) acrylic acid monomers include (meth) acrylic acid, hydroxyl group-containing water-soluble (meth) acrylic acid ester, polyether group-containing water-soluble (meth) acrylic acid ester, amino group-containing water-soluble ( Preferable examples include (meth) acrylic acid esters and phosphoric acid group-containing water-soluble (meth) acrylic acid esters.

  In this embodiment, the reason why the water-soluble (meth) acrylic acid monomer is polymerized with the polymer crosslinking precursor (C) is as follows. That is, the polymer cross-linking precursor (C) is mainly formed in an aqueous solvent, and in consideration of the dispersibility of the resulting polymer cross-linking precursor and the suppression of the reverse reaction, the polymer cross-linking precursor (C) should be handled in an aqueous solvent thereafter. Is preferred. Therefore, a water-soluble (meth) acrylic acid monomer that is also soluble in an aqueous solvent and has an affinity for the linear molecule (B) is copolymerized with the polymer crosslinking precursor (C). .

  The lower critical solution temperature is the temperature of a compound that is liquid at room temperature (23 ° C.) but changes to a solid or slurry state when heated. N-isopropylacrylamide and the like are known as compounds having a lower critical solution temperature.

  In the present embodiment, the water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature is used by thermally polymerizing the water-soluble (meth) acrylic acid monomer and the polymer crosslinking precursor (C). This is because if the water-soluble (meth) acrylic acid monomer has a lower critical solution temperature, it may be precipitated from an aqueous solvent by heating. In addition, even when a film is formed at room temperature (23 ° C.) by photopolymerization such as ultraviolet irradiation, if the water-soluble (meth) acrylic acid monomer has a lower critical solution temperature, polymerization heat is generated in the micro. This is because the temperature rises and water-soluble (meth) acrylic acid monomers may be precipitated.

  In the present invention, a monomer having a lower critical solution temperature is not completely excluded as a copolymerization component, and a monomer having a lower critical solution temperature may be further copolymerized as long as the effects of the present invention are not lost. In particular, when a water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature exists, even if a monomer having a lower critical solution temperature is added, ) Due to the compatibility with the acrylic acid monomer (D), it is expected that the adverse effect of the monomer having the lower critical solution temperature is remarkably reduced.

  Specific examples of the water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature of the present embodiment include (meth) acrylic acid, (meth) acrylic acid (2-hydroxyethyl), (meth) Acrylic acid (3-hydroxypropyl), (meth) acrylic acid (4-hydroxybutyl), (meth) acrylic acid (diethylene glycol), N, N-dimethyl (meth) acrylamide, N-hydroxy (meth) acrylamide, (meta ) Acrylic acid, acrylic acid (phosphoxyethyl), acryloyloxyphosphorylcholine and the like can be preferably mentioned. Among these, N, N-dimethyl (meth) acrylamide or (meth) acrylic acid (2-hydroxyethyl) is particularly preferable in view of excellent water solubility and the resulting film not sticky even in a dry state.

  Polymer obtained when N, N-dimethyl (meth) acrylamide or (meth) acrylic acid (2-hydroxyethyl) is used as the water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature The film made of the crosslinked product (E) has a very high surface smoothness, no stickiness on the surface, and is a beautiful film excellent in transparency. In addition, (meth) acryl means both methacryl and acrylic. Similar designations are interpreted in the same way.

  The compounding amount of the water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature is usually 0.1 to 100,000 mass% with respect to the polymer crosslinking precursor (C), and is 1 to 10,000. It is preferable that it is mass%, and it is especially preferable that it is 200-10000 mass%.

  The polymerization reaction may be performed by a conventional method, and is usually performed by radical polymerization. For example, if desired, a photopolymerization initiator is added to the solution containing the polymer crosslinking precursor (C) and the polymerizable compound (D) and irradiated with ultraviolet rays, or a thermal polymerization initiator is added. By heating, the linear molecule (B) and the polymerizable compound (D) are copolymerized.

  The photopolymerization initiator is not particularly limited as long as it is usually used, for example, benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, Methyl benzoin benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β- Chloranthraquinone, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, (2,4,6-trimethylbenzyldiphenyl) Le) phosphine oxide, 2-benzothiazole -N, it can be used N- diethyldithiocarbamate and the like. In addition, a photoinitiator may be used individually by 1 type and may use 2 or more types together.

The ultraviolet rays are obtained with a high-pressure mercury lamp, a fusion H lamp, a xenon lamp or the like, and the irradiation amount is usually 100 to 500 mJ / cm ² .

  On the other hand, the thermal polymerization initiator is not particularly limited as long as it is usually used. For example, benzoyl peroxide, azobisisobutyronitrile (AIBN), or the like can be used. The heating temperature in the case of using the thermal polymerization initiator may be appropriately selected depending on the decomposition temperature of the thermal polymerization initiator, but is usually about 0 to 130 ° C.

  The polymer crosslinked product (E) may be purified by a conventional method, for example, sequentially washed with water, tetrahydrofuran and dimethylformamide.

  According to the above method, the polymer cross-linking precursor (C) can be easily produced simply by mixing and stirring the polymer (A) and the linear molecule (B), and the obtained polymer. A rotaxane structure having an interlock structure is obtained by copolymerizing the linear molecule (B) of the crosslinking precursor (C) and a water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature. The polymer crosslinked body (E) containing can be manufactured simply.

  In the obtained crosslinked polymer (E), the cyclic portion of the polymer (A) can move on the side chain of the polymer, etc., so that it has excellent stretchability. It will be beautiful with smoothness and transparency. In addition, since the said elasticity is maintained even when it raises a crosslinking density, the polymeric crosslinked body (E) with a high elongation at break and a high elastic modulus is obtained.

  In order to obtain a film of the crosslinked polymer (E) according to this embodiment, for example, the crosslinked polymer precursor (C) and a water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature. And then poured into a mold, or coated on a substrate by a roll-to-roll method, and then copolymerized by heating or ultraviolet irradiation to form a film-like crosslinked polymer (E) it can.

  The thickness of a film is 50-5000 micrometers normally, Preferably it is 100-2000 micrometers, Most preferably, it is 150-1500 micrometers.

  The polymer cross-linked product (E) is a plastic excellent in stress relaxation properties, in particular, as a film having a smooth and clean surface, and having a sufficient film strength and excellent stretchability, etc. Useful for various applications.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
(1) Synthesis of polymer (A) 5 g of α-cyclodextrin (manufactured by Nacalai Tesque) was dissolved in 50 ml of dimethylformamide, and to this solution was added tolylene 2,4-diisocyanate-terminated polypropylene glycol (manufactured by Aldrich, Mn: 1,000). ) 3.4 g and 200 mg of dibutyltin dilaurate (manufactured by Tokyo Chemical Industry Co., Ltd.), which is a tin catalyst, were added and stirred overnight at room temperature.

  The reaction solution is poured into ether and precipitated, and the collected solid is dried, washed with water and dried again, and has α-cyclodextrin as a cyclic molecule, a polypropylene glycol chain as a linking molecule, and a linking molecule. Thus, 4.6 g of polymer (A) in which 3 to 5 cyclic molecules were connected to each other was obtained.

(2) Synthesis of linear molecule (B1) 3.5 g of polyethylene glycol methacrylate (manufactured by Aldrich, Mn: 526) was dissolved in 15 ml of methylene chloride, and 3,5-dimethylphenyl isocyanate (manufactured by Aldrich) was dissolved in this solution. 1.5 g and 200 mg of dibutyltin dilaurate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a tin catalyst were added and stirred overnight at room temperature.

  The reaction solution is filtered, evaporated to dryness, washed by adding hexane, polyethylene glycol having a blocking group composed of 3,5-dimethylphenyl group at one end and a methacryloyl group at the other end ( 3.2 g of MA-PEG-DPI; linear molecule (B1)) was obtained.

(3) Production of polymer cross-linking precursor (C) 100 mg of polymer (A) was dissolved in 1 ml of 0.4 wt% sodium hydroxide aqueous solution, and 200 mg of linear molecule (B1) was added to this solution mechanically. When ultrasonic irradiation (35 Hz) was performed for 5 minutes while stirring, the solution became cloudy and the viscosity increased. Such a cloudy substance having an increased viscosity is considered to be a polymer crosslinking precursor (C) in which the cyclic part of the polymer (A) includes the linear molecule (B1).

(4) Production of polymer crosslinked product (E) N, as a water-soluble (meth) acrylic acid monomer (D) having no lower critical solution temperature, is added to the cloudy product considered to be a polymer crosslinked precursor (C). N-dimethylacrylamide 2.0g was added and it stirred until it became uniform. Next, 40 μl of a 1: 1 eutectic mixture of 1-hydroxy-cyclohexyl-phenyl-ketone and benzophenone (manufactured by Ciba Specialty Chemicals, IRUGACURE 500), which is a photopolymerization initiator, was added, and after deaeration with a vacuum pump Went. Thereafter, as shown in FIG. 3, the mixed solution obtained by the above operation is poured inside the silicone rubber mold (thickness 1 mm) on the glass plate, and the glass plate is covered so that air does not enter, A gel-like film was obtained by irradiating with ultraviolet rays for 3 minutes (irradiation conditions: illuminance: 3.0 mW / cm ² , light amount: 300 mJ / cm ² ).

  The obtained gel-like film is obtained by using the linear molecule (B1) and the lower critical solution via the polymerizable functional group (methacryloyl group) of the linear molecule (B1) in the polymer crosslinking precursor (C). Polymer cross-linked product (E) obtained by copolymerization with water-soluble (meth) acrylic acid monomer (D) having no temperature (on the side of the polymer having a terminal block group at the cyclic portion of polymer (A)) When the polymer of the water-soluble (meth) acrylic acid monomer (D) that includes the chain and does not have the lower critical solution temperature is composed of a crosslinked polymer (E) that forms the main chain of the polymer. Conceivable. The details are considered as described in FIG.

  The obtained crosslinked polymer (E) made of a gel-like film is taken out by removing the upper glass plate shown in FIG. 3, washed by sequentially immersing in water, tetrahydrofuran and dimethylformamide, and then dried. A transparent polymer crosslinked film (thickness: 1.0 mm, non-stretched) was obtained.

[Example 2]
A crosslinked polymer (E) and a crosslinked polymer film were produced in the same manner as in Example 1 except that the amount of the polymer (A) was changed to 300 mg.

Example 3
Polyethylene glycol (manufactured by Aldrich, Mn: 10000) is dissolved in 40 ml of methylene chloride, and 1.6 g of 2-methacryloyloxyethyl isocyanate (manufactured by Showa Denko, Karenz MOI) and dibutyltin dilaurate as a tin catalyst are dissolved in this solution. 200 mg (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and stirred overnight at room temperature.

  The obtained solution was concentrated and then precipitated in diethyl ether, and the precipitate was recovered. As a result, 5.8 g of polyethylene glycol having a methacryloyl group at both ends (PEG 10000 DA; linear molecule (B2)) was obtained.

  The cross-linked polymer (E) was changed in the same manner as in Example 1 except that the blending amount of the polymer (A) was changed to 300 mg and 440 mg of the linear molecule (B2) was used instead of the linear molecule (B1). ), And a polymer crosslinked film was produced.

  The obtained crosslinked polymer (E) has a lower limit to the linear molecule (B2) via the polymerizable functional group (methacryloyl group) of the linear molecule (B2) in the polymer crosslinked precursor (C). Polymer cross-linked product (E) obtained by copolymerization with water-soluble (meth) acrylic acid monomer (D) having no critical solution temperature (in the cyclic part of polymer (A), linear molecule (B) A polymer cross-linked product (E) in which a polymer of a water-soluble (meth) acrylic acid monomer (D) that includes a main body part and does not have a lower critical solution temperature constitutes a main chain of the polymer. It is believed that there is. The details are considered as described in FIG.

[Comparative Example 1]
A crosslinked polymer (E) and a crosslinked polymer film were produced in the same manner as in Example 1 except that 15 mg of polyethylene glycol diacrylate (Aldrich, PEG400DA) was used instead of the polymer (A).

[Comparative Example 2]
A polymer crosslinked product (E) and a polymer crosslinked product film were produced in the same manner as in Example 3 except that the polymer (A) was not used.

[Test Example 1]
About the crosslinked polymer film obtained in Examples and Comparative Examples, a tensile tester (manufactured by Shimadzu Corp., Autograph AG-IS) was used to conform to JIS K-7127 at a test speed of 10 mm / min. The elongation at break (%) was measured. The results are shown in Table 1.

  In addition, the elastic modulus (MPa) was derived from the slope of the linear portion of the stress-strain curve obtained by measuring the elongation at break. The results are shown in Table 1.

  As can be seen by comparing Example 1 and Comparative Example 1 in Table 1 or Example 3 and Comparative Example 2, the crosslinked polymer films obtained in the Examples have a high elongation at break and an elastic modulus. It was expensive. From the fact that the elongation at break is large, it can be seen that the film is excellent in stretchability, and from the fact that the elastic modulus is high, it can be seen that the film has high film strength.

  Furthermore, when the polymer crosslinked body film obtained by each Example was visually observed, those polymer crosslinked body film was excellent in surface smoothness and transparency, and was a beautiful film without the stickiness of the surface.

  The present invention is suitable for producing a crosslinked polymer having a rotaxane structure. The resulting crosslinked polymer is useful as a plastic excellent in stress relaxation properties, particularly as a film having a smooth and clean surface and excellent stretching properties while having sufficient film strength.

Claims (2)

A polymer having two or more cyclic moieties;
A straight-chain molecule having a blocking group that does not leave a cyclic moiety that includes a linear molecule at one end and a polymerizable functional group at the other end and / or a straight chain having a polymerizable functional group at both ends. Mixed with a chain molecule, and for all or a part thereof, an inclusion complex of a rotaxane structure in which the opening of the cyclic portion is skewered with the linear molecule is formed,
Next, a method for producing a crosslinked polymer comprising copolymerizing a polymerizable functional group of the linear molecule and a water-soluble (meth) acrylic acid monomer having no lower critical solution temperature ,
The cyclic portion of the polymer is at least one selected from the group consisting of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin, or from the group consisting of cyclic polyether, cyclic polyester, cyclic polyetheramine and cyclic polyamine. At least one selected,
The polymerizable functional group of the linear molecule is a (meth) acryloyl group, a vinyl group, an epoxy group, an acetylene group, or an oxetanyl group,
The water-soluble (meth) acrylic acid monomer having no lower critical solution temperature includes (meth) acrylic acid, hydroxyl group-containing water-soluble (meth) acrylic acid ester, polyether group-containing water-soluble (meth) acrylic acid ester, amino A method for producing a crosslinked polymer, which is a group-containing water-soluble (meth) acrylic acid ester or a phosphoric acid group-containing water-soluble (meth) acrylic acid ester . An opening of the cyclic part having a polymer having two or more cyclic parts, a blocking group that prevents the cyclic part that encloses the linear molecule at one end from leaving, and a polymerizable functional group at the other end A linear molecule capable of forming a rotaxane clathrate complex penetrating the linear portion with a linear molecule and / or a linear functional molecule and / or having a polymerizable functional group at both ends, and directly opening the opening of the cyclic portion. Polymerizable functional group of the linear molecule of the polymer cross-linking precursor obtained by mixing the polymer and the linear molecule capable of forming the inclusion complex of the rotaxane structure penetrating through the chain molecule in a skewered manner And a crosslinked polymer obtained by copolymerizing a water-soluble (meth) acrylic acid monomer having no lower critical solution temperature ,
The cyclic portion of the polymer is at least one selected from the group consisting of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin, or from the group consisting of cyclic polyether, cyclic polyester, cyclic polyetheramine and cyclic polyamine. At least one selected,
The polymerizable functional group of the linear molecule is a (meth) acryloyl group, a vinyl group, an epoxy group, an acetylene group, or an oxetanyl group,
The water-soluble (meth) acrylic acid monomer having no lower critical solution temperature includes (meth) acrylic acid, hydroxyl group-containing water-soluble (meth) acrylic acid ester, polyether group-containing water-soluble (meth) acrylic acid ester, amino A cross-linked polymer, which is a group-containing water-soluble (meth) acrylic acid ester or a phosphoric acid group-containing water-soluble (meth) acrylic acid ester .

Images