JP2017149793A - Polymer material whose form is capable of form control by photic stimulation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new polymer capable of controlling a flowing state and a non-flowing state.SOLUTION: There is provided a crosslinked polymer obtained by crosslinking a precursor polymer, in which the precursor polymer being a polymer obtained by introducing a lophine group (2,4,5-triphenylimidazole group) into at least one terminal of a skeleton polymer, the crosslinked polymer has a structure where the lophine group in the precursor polymer is crosslinked between molecules by covalent bond, and, in the crosslinked polymer, the crosslinking is cleaved by photic stimulation, it is reversibly changed from a solid state to a liquid state, and is again returned to a solid state by stopping the photic stimulation. In the crosslinked polymer, the skeleton polymer is polyacrylate having a four-branch structure or polysiloxane having a four-branch structure. In the crosslinked polymer, all the terminals of the polyacrylate having a four-branch structure have lophine groups.SELECTED DRAWING: None

Description

  The present invention relates to a polymer capable of controlling a flow state and a non-flow state by the presence or absence of light stimulation, and a method for controlling the fluidity of the polymer.

  In optical modeling and adhesives, thermosetting resins and photocurable resins are used as materials whose fluidity changes due to external stimuli. However, these materials have a problem that a dedicated device is required for the curing treatment, and that once processed, it is difficult to reprocess and the material is not recyclable.

  In contrast, substances that do not contain solvents and can be reversibly switched between solid and liquid at room temperature by external stimuli are expected to be applied not only to the environment but also to reusable resins and adhesives. Is done. As one of such attempts, a compound that can be fluidized and non-fluidized by light stimulation has been reported, and its application to adhesives and the like has been studied (for example, Patent Document 1 and Non-Patent Document 1). However, the change in the flow state in Patent Document 1 is merely obtained by reducing the crystallinity of regularly arranged molecules by light stimulation, and expects high strength and adhesion as a material. It was not possible and the range of molecular structure design was limited. In addition, since the compound of Patent Document 1 uses a photoisomerization reaction of azobenzene, it is necessary to change the wavelength range of light to be irradiated in order to control fluidity.

  On the other hand, as an aspect of the adhesive, generally, there are known types such as a reaction type, a solvent type, an aqueous type, a hot melt type, and a pressure sensitive type. Among these, the hot melt type adhesive is Most widely used for bonding metal materials. Such a hot melt adhesive can be applied to a material in a fluidized state by heating and melting the adhesive, and then cooled to solidify the adhesive and bond the materials together. The bonding method using the hot-melt adhesive has advantages that it is safe because it does not contain an organic solvent, and can be applied to a material in a molten state, so that various coating patterns can be used. However, since the adhesive is melted at a high temperature and used, there are problems such as being unsuitable for bonding in an environment where heating is not desirable or bonding between materials having low heat resistance.

JP 2011-256291 A

Adv. Mater. 2012, 24, 2353-2356

  Therefore, the present invention is a novel polymer that can control the flow state and the non-flow state by light stimulation. More specifically, the present invention has a characteristic that can reversibly repeat a liquid state and a solid state by light stimulation. It is an object of the present invention to develop a molecule and to provide a method for controlling the fluidity of such a polymer by light stimulation.

  As a result of intensive studies to solve the above problems, the present inventor has found that a covalent bond is cleaved by a light stimulus and is crosslinked by a functional group having a photoresponsive property that the bond re-forms when no light stimulus is applied. By using molecules, it was found that the flow state of the crosslinked polymer can be controlled by reversibly changing the molecular shape depending on the presence or absence of light stimulation, and the present invention has been completed.

（式中、Ｒは、カルボン酸エステル基であり；ｎは、２〜２００の整数であり;４つの分岐鎖はいずれも同じ構造を有している。）
又は、以下の構造を有する四分岐型ポリシロキサン

（式中、Ｒは、水素またはアルキル基；ｎは、２〜２００の整数であり;４つの分岐鎖はいずれも同じ構造を有している。）
である、上記（１）に記載の架橋高分子
を提供するものである。 That is, the present invention in one aspect,
(1) A crosslinked polymer obtained by crosslinking a precursor polymer, wherein the precursor polymer is a polymer in which a lophine group is introduced into at least one end of a skeleton polymer; The lophine group in the precursor polymer has a structure in which molecules are cross-linked by a covalent bond; the cross-linked polymer can be reversibly changed from a solid state to a liquid state by cleavage of the cross-link by light stimulation. The crosslinked polymer characterized by the above;
(2) The crosslinked polymer according to (1), wherein the light stimulation is irradiation with ultraviolet rays;
(3) The crosslinked polymer according to (1) or (2) above, wherein the crosslinked polymer returns to a solid state again by stopping the light stimulation;
(4) The crosslinked polymer according to any one of (1) to (3), wherein the skeleton polymer is polyacrylate or polysiloxane;
(5) The crosslinked polymer according to (4), wherein the skeleton polymer is a polyacrylate having a four-branched structure or a polysiloxane having a four-branched structure;
(6) The crosslinked polymer according to (5) above, which has a lophine group at all terminals of the polyacrylate having the four-branched structure;
(7) The crosslinked polymer according to any one of (1) to (6), wherein the skeleton polymer has a molecular weight in a range of 1,000 to 100,000;
(8) The cross-linked polymer according to any one of (1) to (7), wherein the skeleton polymer has a glass transition temperature in a range of −130 ° C. to 30 ° C .; and (9) the precursor high Four-branched polyacrylate whose molecule has the following structure

(Wherein R is a carboxylic acid ester group; n is an integer from 2 to 200; all four branched chains have the same structure.)
Or a four-branched polysiloxane having the following structure:

(In the formula, R is hydrogen or an alkyl group; n is an integer of 2 to 200; all four branched chains have the same structure.)
The crosslinked polymer as described in (1) above is provided.

（式中、Ｒは、カルボン酸エステル基であり；ｎは、２〜２００の整数であり;４つの分岐鎖はいずれも同じ構造を有している。）
又は、以下の構造を有する四分岐型ポリシロキサン

（式中、Ｒは、水素またはアルキル基；ｎは、２〜２００の整数であり;４つの分岐鎖はいずれも同じ構造を有している。）
である、上記（１０）に記載の化合物；
を提供するものであり、及び
（１７）上記（１０）〜（１６）のいずれか１に記載の化合物が、前記ロフィン基において分子間又は分子内で架橋してなる、架橋高分子
を提供するものである。 In another embodiment, the present invention is also directed to a polymer compound that is a precursor of the crosslinked polymer. That is, the present invention
(10) A compound having a lophine group at at least one end of the skeleton polymer, which is in a liquid state at room temperature;
(11) The compound according to (10), wherein the skeleton polymer is polyacrylate or polysiloxane;
(12) The compound according to (11), wherein the skeleton polymer is a polyacrylate having a four-branched structure or a polysiloxane having a four-branched structure;
(13) The compound according to (12) above, which has a lophine group at all terminals of the polyacrylate having the four-branched structure.
(14) The compound according to any one of (10) to (13), wherein the skeleton polymer has a molecular weight in the range of 1,000 to 100,000.
(15) The compound according to any one of (10) to (14), wherein the skeleton polymer has a glass transition temperature in the range of -130 ° C to 30 ° C;
(16) Four-branched polyacrylate having the following structure

(Wherein R is a carboxylic acid ester group; n is an integer from 2 to 200; all four branched chains have the same structure.)
Or a four-branched polysiloxane having the following structure:

(In the formula, R is hydrogen or an alkyl group; n is an integer of 2 to 200; all four branched chains have the same structure.)
The compound according to (10), which is
And (17) a crosslinked polymer, wherein the compound according to any one of the above (10) to (16) is crosslinked between the molecules or within the molecule at the lophine group. Is.

（式中、Ｒは、カルボン酸エステル基であり；ｎは、２〜２００の整数であり;４つの分岐鎖はいずれも同じ構造を有している。）
又は、以下の構造を有する四分岐型ポリシロキサン

（式中、Ｒは、水素またはアルキル基；ｎは、２〜２００の整数であり;４つの分岐鎖はいずれも同じ構造を有している。）
である、上記（１８）に記載の方法
を提供するものである。 In a further aspect, the present invention provides a method for reversibly controlling the fluidity of a polymer material using the crosslinked polymer. That is, the present invention
(18) A method for reversibly controlling the fluidity of a polymer material, wherein a liquid precursor polymer having a lophine group introduced into at least one end of a skeleton polymer is crosslinked between molecules. Obtaining a cross-linked polymer in a solid state, wherein the cross-linked polymer has a structure in which the lophine group in the precursor polymer is cross-linked between molecules by a covalent bond; The method comprising the step of cleaving the cross-linking by imparting a stimulus and changing the cross-linked polymer from a solid state to a liquid state;
(19) The method according to (18) above, wherein the light stimulation is irradiation with ultraviolet rays;
(20) The method according to (18) or (19), further comprising a step of returning the solid state again by stopping the light stimulation;
(21) The method according to any one of (18) to (20), wherein the crosslinking is performed in the presence of a base;
(22) The step of obtaining the solid state cross-linked polymer gives photo-stimulation to the precursor polymer in which the lophine group is cross-linked in the molecule and cleaves the cross-link in the molecule; The method according to any one of (18) to (21) above, which is a step of obtaining a solid-state crosslinked polymer by crosslinking between molecules;
(23) The method according to any one of (18) to (22), wherein the skeleton polymer is polyacrylate or polysiloxane;
(24) The method according to (23) above, wherein the skeleton polymer is a compound according to (11) above, which is a polyacrylate having a four-branched structure or a polysiloxane having a four-branched structure;
(25) The method according to (24) above, wherein the polyacrylate having a four-branched structure has a lophine group at all terminals thereof;
(26) The method according to any one of (18) to (25), wherein the backbone polymer has a molecular weight in the range of 1,000 to 100,000.
(27) The method according to any one of (18) to (26), wherein the skeleton polymer has a glass transition temperature in the range of -130 ° C to 30 ° C; and (28) the precursor polymer is Four-branched polyacrylate having the following structure

(Wherein R is a carboxylic acid ester group; n is an integer from 2 to 200; all four branched chains have the same structure.)
Or a four-branched polysiloxane having the following structure:

(In the formula, R is hydrogen or an alkyl group; n is an integer of 2 to 200; all four branched chains have the same structure.)
The method described in (18) above is provided.

In another aspect, the present invention also provides an adhesive containing the above crosslinked polymer and an adhesion method using the same. That is, the present invention
(29) An adhesive comprising the crosslinked polymer according to any one of (1) to (9) above;
(30) The adhesive according to (29), which is a hot-melt adhesive;
(31) A material having on its surface the crosslinked polymer according to any one of (1) to (9) above;
(32) A method for adhering two or more materials using the method according to any one of (18) to (28) above, and (33) the above (1) The resin material for 3D printers containing the crosslinked polymer of any one of-(9).
Also related.

  The conventional substance capable of controlling the flow state by light stimulation uses the difference in the crystalline state of the molecule for the change of the flow state, and therefore the range of molecular design is remarkably limited. In contrast, the present invention introduces a functional group capable of reversible cleavage (crosslinking / decrosslinking) of a covalent bond that can be cleaved / reformed by light stimulation, thereby changing the flow state between solid and liquid. Can be controlled. Therefore, since such a functional group can be introduced into an arbitrary skeleton structure, the applicable range is much wider than that of conventional materials, and a desired material can be provided according to various uses. In the present invention, since the covalent bond can be cleaved and reformed only by the on / off operation of the light stimulus, the light emitted for controlling the fluidity as in the conventional technique using the intramolecular photoisomerization reaction. There is no need to change the wavelength range.

  In addition, the present invention can change the flow state from a solid to a liquid only by light stimulation without performing heating or the like, so that heating is not desired without impairing the convenience of existing hot melt adhesives. This is advantageous in that it can be applied to bonding between materials with low heat resistance. Furthermore, when the crosslinked polymer of the present invention is used as a resin material for a 3D printer, fine adjustment can be made again by applying a light stimulus even after being molded once.

  Hereinafter, embodiments of the present invention will be described. The scope of the present invention is not limited to these descriptions, and other than the following examples, the scope of the present invention can be appropriately changed and implemented without departing from the spirit of the present invention.

1. Crosslinked polymer The crosslinked polymer of the present invention has a structure in which a precursor polymer in which a lophine group is introduced into at least one end of a skeleton polymer is crosslinked between the molecules by a covalent bond. Here, the precursor polymer is a fluid compound at room temperature, that is, a liquid state compound, and a solid crosslinked polymer having non-fluidity is obtained by crosslinking between molecules.

  And by giving a light stimulus to the cross-linked polymer, the cross-linking (covalent bond) in the lophine group can be cleaved and changed from the solid state to the liquid state again. Furthermore, by stopping the light stimulation and allowing to stand at room temperature, the cross-linking is spontaneously formed again, and the cross-linked polymer can be returned to the solid state. By utilizing such a reaction, the fluidity of the crosslinked polymer can be reversibly controlled by light stimulation.

  The light stimulus used in the present invention is preferably ultraviolet irradiation. The wavelength range of the ultraviolet light is 10 to 400 nm, preferably 200 to 400 nm, more preferably 315 to 400 nm. Moreover, it is preferable to give light stimulation on the temperature conditions of 10-60 degreeC.

  As described above, as the skeleton polymer constituting the main chain of the precursor polymer used in the present invention, those in a fluid liquid state at normal temperature are used. As such a skeleton polymer, those known in the art can be used, for example, polyacrylate polymer, polymethacrylate polymer, polystyrene polymer, polyethylene polymer, polyamide polymer, polyester polymer, polyurethane polymer. A polymer or a polysiloxane-based polymer can be used. Preferably, it is polyacrylate or polysiloxane. More preferred is poly (alkyl acrylate) or polydimethylsiloxane (PDMS). As the skeleton polymer, not only a linear polymer but also a polymer having a branched structure can be used. Preferably, a polyacrylate having a four-branched structure or a polysiloxane having a four-branched structure is used. be able to.

  Further, the skeleton polymer is preferably in the range of 1,000 to 500,000, more preferably in the range of 3,000 to 100,000 (number average) from the viewpoint of being in a fluid liquid state at normal temperature. Molecular weight). Similarly, it preferably has a glass transition temperature (Tg) in the range of -130 ° C to 30 ° C, more preferably -130 to 0 ° C.

In the precursor polymer used in the present invention, a lophine group is introduced into at least one terminal of the skeleton polymer. The lophine group is a 2,4,5-triphenylimidazole group and has the following structure.

Each phenyl group in the lophine group may be independently substituted, for example, a halogen atom, an optionally substituted alkyl group, alkenyl group, aryl group, sulfo group, carboxyl group, ester group, amide It may be substituted with 1 to 5 identical or different substituents selected from the group consisting of groups. In the present specification, “alkyl” may be any of an aliphatic hydrocarbon group composed of linear, branched, cyclic, or a combination thereof. The number of carbon atoms of the alkyl group is not particularly limited, for example, 1-20 carbon atoms _{(C 1-20),} several 3 to 15 carbon atoms _{(C 3-15),} 5 to 10 carbon atoms _{(C 5 to 10} ). In the present specification, “aryl” may be either a monocyclic or condensed polycyclic aromatic hydrocarbon group, and a hetero atom (for example, an oxygen atom, a nitrogen atom, or a sulfur atom) as a ring constituent atom Etc.) may be an aromatic heterocyclic ring. In this case, it may be referred to as “heteroaryl” or “heteroaromatic”. When aryl is either a single ring or a fused ring, it can be attached at all possible positions.

  The lophine group is introduced into at least one terminal of the skeleton polymer, and preferably 2 or more. For example, in the case of a polyacrylate having a four-branched structure, a lophine group can be introduced at each end of four branched chains. The number of such lophine groups can be changed according to the desired physical properties of the crosslinked polymer.

Non-limiting specific examples of the precursor polymer used in the present invention include the following four-branched polyacrylate having a lophine group at the terminal.

  In the formula, R is a carboxylate group, preferably —COOMe, —COOEt, —COOBu, —COOHex, more preferably —COOBu. n is an integer of 2 to 200, preferably 2 to 20. In addition, although all four branched chains have the same structure in the formula, as described above, it is not always necessary to have a lophine group at the end of every branched chain. Further, the length of the branched chain, that is, the value of n is not necessarily the same in each branched chain, and may be different.

A cross-linked molecule obtained by using such a 4-branched polyacrylate as a precursor polymer and cross-linking between molecules in the lophine group has the following structure.

Further, specific examples of the precursor polymer used in the present invention include the following four-branched polysiloxane having a lophine group at the terminal.

  In the formula, R is hydrogen or an alkyl group, preferably methyl. n is an integer of 2 to 200, preferably 2 to 20. In addition, although all four branched chains have the same structure in the formula, as described above, it is not always necessary to have a lophine group at the end of every branched chain. Further, the length of the branched chain, that is, the value of n is not necessarily the same in each branched chain, and may be different.

2. In another embodiment, the present invention reversibly controls the fluidity of a polymer material by utilizing photo-stimulated crosslinking formation and cleavage reaction between the precursor polymer and the crosslinked polymer. Also related to the method.

More particularly, the method of the present invention comprises:
<Step 1> A step of obtaining a solid state cross-linked polymer by cross-linking a liquid state precursor polymer having a lophine group introduced into at least one terminal of the skeleton polymer, and <Step 2> solid It includes a step of cleaving the cross-linking by applying a light stimulus to the cross-linked polymer in a state to change the cross-linked polymer from a solid state to a liquid state.

  In the step 1, the crosslinked polymer has a structure in which the terminal lophine groups in the precursor polymer are crosslinked between the molecules by covalent bonds as described above. The precursor polymer is a compound in a liquid state having fluidity at room temperature, and a solid crosslinked polymer having non-fluidity is obtained by crosslinking between molecules. Thereafter, in step 2, the bridge (covalent bond) in the lophine group is cleaved by light stimulation, and the solid state can be changed to the liquid state again.

  The crosslinking reaction in step 1 can be allowed to proceed under ordinary conditions in the art, but preferably in the presence of a base such as sodium hydroxide, potassium hydroxide, calcium hydroxide, and an oxidizing agent such as potassium ferricyanide. Done.

  About the light stimulation in the process 2, Preferably, it is irradiation of an ultraviolet-ray, The detail is as above-mentioned.

The method of the present invention also includes
<Step 3> A step of returning to the solid state again by stopping the light stimulation can be further included.

  In step 3, by stopping the light stimulation and allowing to stand at room temperature, the cross-linking is spontaneously formed again, and the cross-linked polymer can be returned to the solid state. By repeating these steps 2 and 3, the fluidity of the crosslinked polymer can be reversibly controlled.

  Further, as another embodiment in Step 1, the precursor polymer in which the lophine group is crosslinked in the molecule is subjected to photo stimulation to cleave the crosslinking in the molecule, and then the precursor polymer is crosslinked between the molecules. It can also be set as the process of obtaining the crosslinked polymer of a solid state by making it.

That is, when a precursor polymer having a lophine group at a plurality of ends is crosslinked under a low concentration condition, a compound having an intramolecular crosslinking structure is generated. However, since the compound is a liquid having fluidity at room temperature, It can be used in place of the precursor polymer (monomer) described above. Such a compound having an intramolecular crosslinked structure is preferred when it is desired to provide the crosslinked polymer of the present invention in a non-flowing state. As a non-limiting example, when the precursor polymer is a four-branched polyacrylate, the reaction from the intramolecular crosslinked structure compound to a crosslinked polymer (crosslinked between molecules) is as follows.

3. Applications The crosslinked polymer of the present invention has a characteristic that the flow state of solid-liquid can be controlled by light stimulation, and is therefore suitable as an adhesive or a resin material for 3D printers. Therefore, the present invention is also directed to an adhesive or a resin material for a 3D printer containing the crosslinked polymer. As the adhesive, a hot melt adhesive is preferable. The adhesive containing the crosslinked polymer of the present invention has an advantage that it can be applied to adhesion in an environment where heating is not desirable or adhesion between materials having low heat resistance.

  Moreover, the adhesion | attachment method of material including performing adhesion | attachment and desorption of two or more materials using the method including the above-mentioned processes 1-3 is also the object of this invention. When used as such an adhesive, if it is preferable to provide a solid state adhesive, a crosslinked polymer crosslinked between molecules can be provided as it is. In this case, at the time of use, a plurality of materials can be bonded by irradiating with light, once in a liquid state, applying to a desired material, and then solidifying. Such an embodiment is preferable when the adhesive is not easily spilled during transportation or when it is easy to handle by hand.

  On the other hand, when provision in a liquid state is preferable, the precursor polymer is provided in the form of a compound crosslinked in the molecule, and the intramolecular crosslinked compound is applied to a desired material and solidified to form a plurality of molecules. The material can also be glued. Such a mode is suitable for a case where it is necessary to pour into a narrow place or a case where it is poured into a mold.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these.

1. Synthesis of Precursor Polymer A four-branched polyacrylate having a lophine group at the end was synthesized as shown below.

ペンタエリスリトールテトラキス（２−ブロモイソブチレート）（５．０ ｇ）、アクリル酸ブチル（１２．３ｍＬ）、臭化銅（Ｉ)（３９０ｍｇ）、４，４’−ジノニル−２，２’−ビピリジル（２．２３ｇ）、及びトルエン（１２ｍＬ）を混合し、８０℃で４時間、原子移動ラジカル重合を行った。反応混合物のアルミナカラムカラムクロマトグラフィによる精製を経て四分岐構造を有する末端臭素型ポリ（ブチルアクリレート）を１０．７ｇ得た。分子量（Ｍｎ）は、２３００であった。 Step a: Terminal bromine type poly (butyl acrylate) (Compound 1)

Pentaerythritol tetrakis (2-bromoisobutyrate) (5.0 g), butyl acrylate (12.3 mL), copper (I) bromide (390 mg), 4,4′-dinonyl-2,2′-bipyridyl (2.23 g) and toluene (12 mL) were mixed, and atom transfer radical polymerization was performed at 80 ° C. for 4 hours. The reaction mixture was purified by alumina column column chromatography to obtain 10.7 g of terminal bromine-type poly (butyl acrylate) having a four-branched structure. The molecular weight (Mn) was 2300.

The amount of monomers used for the polymerization was changed and synthesized in the same manner as terminal brominated poly (butyl acrylate) having different molecular weights.

四分岐構造を有する末端臭素型ポリ（ブチルアクリレート）（５．４ｇ）、アジ化ナトリウム（２．３ｇ）、及びＮ，Ｎ−ジメチルホルムアミド（１５ｍＬ）を混合し、室温で１４時間攪拌した。反応混合物を多量の水に加え、クロロホルムによる抽出を経て、四分岐構造を有する末端アジド型ポリ（ブチルアクリレート）を５．２ｇ得た。 Step b: Terminal azide-type poly (butyl acrylate) (Compound 2)
To compound 1 obtained in step a, sodium azide was allowed to act as an end capping agent to obtain compound 2.

Terminal bromine type poly (butyl acrylate) having a four-branched structure (5.4 g), sodium azide (2.3 g), and N, N-dimethylformamide (15 mL) were mixed and stirred at room temperature for 14 hours. The reaction mixture was added to a large amount of water and extracted with chloroform to obtain 5.2 g of a terminal azide-type poly (butyl acrylate) having a four-branched structure.

四分岐構造を有する末端アジド型ポリ（ブチルアクリレート）（３．８ ｇ）、２−（４’−プロピニルオキシフェニル）−４，５−ジフェニルイミダゾール（２．２ｇ）、臭化銅（Ｉ)（８８９ｍｇ）、Ｎ，Ｎ，Ｎ’，Ｎ’’，Ｎ’’−ペンタメチルジエチレントリアミン（１．３ｍＬ）、及びＮ，Ｎ−ジメチルホルムアミド（２０ｍＬ）を混合し、室温で3時間攪拌した。反応混合物のアルミナカラムカラムクロマトグラフィによる精製を経て四分岐構造を有する末端ロフィン型ポリ（ブチルアクリレート）を３．０ｇ得た。 Step c: Terminal lophine-type poly (butyl acrylate) (Compound 3)
Compound 3 in which a lophine group was introduced at the terminal was obtained by Huisgen cycloaddition reaction between compound 2 obtained in step b and the lophine derivative.

Terminal azide-type poly (butyl acrylate) having a 4-branched structure (3.8 g), 2- (4′-propynyloxyphenyl) -4,5-diphenylimidazole (2.2 g), copper (I) bromide ( 889 mg), N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine (1.3 mL), and N, N-dimethylformamide (20 mL) were mixed and stirred at room temperature for 3 hours. The reaction mixture was purified by alumina column column chromatography to obtain 3.0 g of terminal lophine-type poly (butyl acrylate) having a four-branched structure.

四分岐型構造を有する末端ロフィン型ポリ（ブチルアクリレート）（１．９５ｇ）のトルエン溶液（２０ｍＬ）に、水（３０ｍＬ）、水酸化ナトリウム（１．１２ｇ）、及びフェリシアン化カリウム（６．５８ｇ）を加え、０℃で３０分間激しく攪拌した。反応混合物の有機層を水で洗浄したのちに濃縮し、減圧で乾燥させることで架橋高分子を１．４４ｇ得た。 2. Synthesis of Crosslinked Polymer Compound 3 obtained in Step c was crosslinked between molecules to obtain a crosslinked polymer (Compound 4).

Water (30 mL), sodium hydroxide (1.12 g), and potassium ferricyanide (6.58 g) were added to a toluene solution (20 mL) of terminal lophine-type poly (butyl acrylate) having a four-branched structure (1.95 g). In addition, the mixture was vigorously stirred at 0 ° C. for 30 minutes. The organic layer of the reaction mixture was washed with water, concentrated and dried under reduced pressure to obtain 1.44 g of a crosslinked polymer.

3. Adhesion and Peeling Test 10 mg of a crosslinked polymer (Compound 4) was sandwiched between two glass slides and irradiated with ultraviolet rays (365 nm) for 1 minute. Although the cross-linked polymer was changed to a liquid state by ultraviolet irradiation, it was confirmed that the two glass slides were well bonded through the solidified cross-linked polymer when allowed to stand for 5 minutes.
Furthermore, when the ultraviolet-ray was irradiated for 1 minute to the adhesion part of the said slide glass, the bridge | crosslinking polymer became liquid again, and two slide glasses peeled.

4). Precursor Polymer (PDMS) Synthesis In addition, a 4-branched polysiloxane having a lophine group at the end was synthesized as shown below.

ペンタエリスリトール（２５５ｍｇ）、ヘキサメチルシクロトリシロキサン（３．３４ｇ）、Ｎ,Ｎ−ジメチルホルムアミド（２０ｍＬ）、テトラヒドロフラン（１０ｍＬ）を混合したのちに、１,５,７−トリアザビシクロ［４．４．０］デカ−５−エン（１０ｍｇ）のＴＨＦ溶液（１ｍＬ）を加え、室温で３０分攪拌した。次いで、反応混合物にヘキサメチルシクロトリシロキサン（１３．４ｇ）のトルエン溶液（４０ｍＬ）を加え２２時間攪拌した。反応混合物にトリエチルアミン（１１ｍＬ）を加えて３分間攪拌した後に、クロロジメチルシラン（４．１７ｍＬ）を加えてさらに３０分間攪拌した。反応混合物の抽出操作による精製を経て四分岐構造を有する末端水素型ポリ（ジメチルシロキサン）を１１．２ｇ得た。分子量（Ｍｎ）は、１０５００であった。 Step a: Terminal hydrogen type poly (dimethylsiloxane) (Compound 5)

After mixing pentaerythritol (255 mg), hexamethylcyclotrisiloxane (3.34 g), N, N-dimethylformamide (20 mL), tetrahydrofuran (10 mL), 1,5,7-triazabicyclo [4.4 .0] dec-5-ene (10 mg) in THF (1 mL) was added and stirred at room temperature for 30 minutes. Next, a toluene solution (40 mL) of hexamethylcyclotrisiloxane (13.4 g) was added to the reaction mixture and stirred for 22 hours. Triethylamine (11 mL) was added to the reaction mixture and stirred for 3 minutes, and then chlorodimethylsilane (4.17 mL) was added and stirred for another 30 minutes. After the purification of the reaction mixture by extraction, 11.2 g of terminal hydrogen type poly (dimethylsiloxane) having a tetra-branched structure was obtained. The molecular weight (Mn) was 10,500.

四分岐構造を有する末端水素型ポリ（ジメチルシロキサン）（５．８ｇ）、４−アリルオキシベンズアルデヒド（１．７ｍＬ）、トルエン（２０ｍＬ）を混合した後に、白金(０) −１,３−ジビニル−１,１,３,３−テトラメチルジシロキサン錯体のキシレン溶液（５０μＬ）を加え７０℃で２．５時間攪拌した。反応混合物の抽出操作による精製を経て四分岐構造を有する末端アルデヒド型ポリ（ジメチルシロキサン）を４．９ｇ得た。 Step b: Terminal aldehyde type poly (dimethylsiloxane) (Compound 6)
4-Allyloxybenzaldehyde was allowed to act on compound 5 obtained in step a to obtain compound 6.

After mixing a terminal hydrogen-type poly (dimethylsiloxane) having a four-branched structure (5.8 g), 4-allyloxybenzaldehyde (1.7 mL), and toluene (20 mL), platinum (0) -1,3-divinyl- A xylene solution of 1,1,3,3-tetramethyldisiloxane complex (50 μL) was added and stirred at 70 ° C. for 2.5 hours. After purification by extraction of the reaction mixture, 4.9 g of terminal aldehyde type poly (dimethylsiloxane) having a tetra-branched structure was obtained.

四分岐構造を有する末端アルデヒド型ポリ（ジメチルシロキサン）（４．０ ｇ）、ベンジル（３．１ｇ）、酢酸アンモニウム（３．４ｇ）、トルエン（１０ｍＬ）、及びメタノール（１０ｍＬ）を混合し、７０℃で４時間攪拌した。反応混合物の抽出操作による精製を経て四分岐構造を有する末端ロフィン型ポリ（ジメチルシロキサン）を２．５ｇ得た。 Step c: Terminal lophine-type poly (dimethylsiloxane) (Compound 7)
Compound 8 in which a lophine group was introduced at the terminal was obtained by reaction of compound 6 obtained in step b with benzyl.

A terminal aldehyde type poly (dimethylsiloxane) having a four-branched structure (4.0 g), benzyl (3.1 g), ammonium acetate (3.4 g), toluene (10 mL), and methanol (10 mL) were mixed, and 70 Stir at 4 ° C. for 4 hours. After purification by extraction of the reaction mixture, 2.5 g of terminal lophine-type poly (dimethylsiloxane) having a four-branched structure was obtained.

四分岐型構造を有する末端ロフィン型ポリ（ジメチルシロキサン）（１．３５ｇ）のヘキサン溶液（１０ｍＬ）に、水（３０ｍＬ）、水酸化ナトリウム（１．２６ｇ）、及びフェリシアン化カリウム（７．４１ｇ）を加え、室温で６０分間激しく攪拌した。反応混合物の有機層を水で洗浄したのちに濃縮し、減圧で乾燥させることで架橋高分子を１．３２ｇ得た。 5. Synthesis of Crosslinked Polymer Compound 8 obtained in Step c was crosslinked between molecules to obtain a crosslinked polymer (Compound 9).

Water (30 mL), sodium hydroxide (1.26 g), and potassium ferricyanide (7.41 g) were added to a hexane solution (10 mL) of terminal lophine-type poly (dimethylsiloxane) (1.35 g) having a tetra-branched structure. In addition, the mixture was vigorously stirred at room temperature for 60 minutes. The organic layer of the reaction mixture was washed with water, concentrated and dried under reduced pressure to obtain 1.32 g of a crosslinked polymer.

Claims (33)

A crosslinked polymer obtained by crosslinking a precursor polymer,
The precursor polymer is a polymer in which a lophine group is introduced into at least one end of a skeleton polymer;
The crosslinked polymer has a structure in which the lophine group in the precursor polymer is crosslinked between molecules by a covalent bond;
The crosslinked polymer may be reversibly changed from a solid state to a liquid state by cleavage of the crosslinking by light stimulation.   The crosslinked polymer according to claim 1, wherein the light stimulation is irradiation with ultraviolet rays.   The crosslinked polymer according to claim 1 or 2, wherein the polymer returns to a solid state again by stopping the light stimulation.   The crosslinked polymer according to claim 1, wherein the skeleton polymer is polyacrylate or polysiloxane.   The crosslinked polymer according to claim 4, wherein the skeleton polymer is a compound according to (11) above, which is a polyacrylate having a four-branched structure or a polysiloxane having a four-branched structure.   The crosslinked polymer according to claim 5, which has a lophine group at all terminals of the polyacrylate having the four-branched structure.   The crosslinked polymer according to any one of claims 1 to 6, wherein the skeleton polymer has a molecular weight in the range of 1,000 to 100,000.   The crosslinked polymer according to any one of claims 1 to 7, wherein the skeleton polymer has a glass transition temperature in a range of -130 ° C to 30 ° C. Four-branch polyacrylate in which the precursor polymer has the following structure

(Wherein R is a carboxylic acid ester group; n is an integer from 2 to 200; all four branched chains have the same structure.)
Or a four-branched polysiloxane having the following structure:

(In the formula, R is hydrogen or an alkyl group; n is an integer of 2 to 200; all four branched chains have the same structure.)
The crosslinked polymer according to claim 1, wherein   A compound having a lophine group at at least one terminal of a skeleton polymer, which is in a liquid state at room temperature. The compound according to claim 10, wherein the backbone polymer is polyacrylate or polysiloxane.   The compound according to claim 11, wherein the skeleton polymer is a compound according to (11) above, which is a polyacrylate having a four-branched structure or a polysiloxane having a four-branched structure.   The compound of Claim 12 which has a lophine group in all the terminals of the polyacrylate which has the said 4 branch structure.   14. The compound according to any one of claims 10 to 13, wherein the backbone polymer has a molecular weight in the range of 1,000 to 100,000. The compound according to any one of claims 10 to 14, wherein the skeleton polymer has a glass transition temperature in the range of -130 ° C to 30 ° C. Four-branched polyacrylate having the following structure

(Wherein R is a carboxylic acid ester group; n is an integer from 2 to 200; all four branched chains have the same structure.)
Or a four-branched polysiloxane having the following structure:

(In the formula, R is hydrogen or an alkyl group; n is an integer of 2 to 200; all four branched chains have the same structure.)
The compound according to claim 10, wherein   A crosslinked polymer obtained by crosslinking the compound according to any one of claims 10 to 16 between molecules or within a molecule in the lophine group. A method for reversibly controlling the fluidity of a polymer material,
A step of obtaining a solid state cross-linked polymer by cross-linking a liquid state precursor polymer having a lophine group introduced into at least one end of the skeleton polymer between molecules, wherein the cross-linked polymer is The lophine group in the precursor polymer has a structure in which molecules are cross-linked by a covalent bond; and the cross-linked polymer is cleaved by applying a light stimulus to the cross-linked polymer in a solid state The method comprising the step of bringing into a liquid state.   The method according to claim 18, wherein the light stimulus is ultraviolet irradiation.   20. The method according to claim 18 or 19, further comprising the step of returning to the solid state again by stopping the light stimulation.   The method according to any one of claims 18 to 20, wherein the crosslinking is performed in the presence of a base.   The step of obtaining the solid-state cross-linked polymer includes applying photo stimulation to the precursor polymer in which the lophine group is cross-linked in the molecule and cleaving the cross-link in the molecule. The method according to any one of claims 18 to 21, which is a step of obtaining a solid-state crosslinked polymer by crosslinking.   The method according to any one of claims 18 to 22, wherein the backbone polymer is polyacrylate or polysiloxane.   The method according to claim 23, wherein the skeleton polymer is a compound according to (11) above, which is a polyacrylate having a four-branched structure or a polysiloxane having a four-branched structure.   The method according to claim 24, wherein the polyacrylate having a tetra-branched structure has a lophine group at all terminals.   26. A method according to any one of claims 18 to 25, wherein the backbone polymer has a molecular weight in the range of 1,000 to 100,000. 27. A method according to any one of claims 18 to 26, wherein the backbone polymer has a glass transition temperature in the range of -130C to 30C. Four-branch polyacrylate in which the precursor polymer has the following structure

(Wherein R is a carboxylic acid ester group; n is an integer from 2 to 200; all four branched chains have the same structure.)
Or a four-branched polysiloxane having the following structure:

(In the formula, R is hydrogen or an alkyl group; n is an integer of 2 to 200; all four branched chains have the same structure.)
The method of claim 18, wherein   The adhesive agent containing the crosslinked polymer of any one of Claims 1-9.   30. The adhesive of claim 29, which is a hot melt adhesive.   The material which has the bridge | crosslinking polymer of any one of Claims 1-9 on the surface.   29. A method of adhering materials comprising adhering and desorbing two or more materials using the method of any one of claims 18-28.   The resin material for 3D printers containing the crosslinked polymer of any one of Claims 1-9.