WO2007069765A1 - Self-repairing material - Google Patents

Abstract

It is intended to provide a self-repairing material which is a crosslinked polymer in which a number of dangling chains are bound to a crosslinked polymer structure, wherein it exhibits a property of a gel in the vicinity of critical state, which has both material shape retention property due to the crosslinked polymer structure and self-repairing property due to the dangling chains by controlling the binding degree of dangling chains to the crosslinked polymer structure and the molecular weight among the crosslinked points in the crosslinked polymer structure to fall within a certain specific range. This self-repairing material can be produced simply at low cost, and has an excellent self-repairing property. A self-repairing structure utilizing this self-repairing material can be also provided.

Description

 Self-healing Materials Technical Field ''

 The present invention relates to a self-healing material that naturally heals even if a scratch occurs on the surface.

 More specifically, the present invention relates to a crosslinked polymer in which a number of dangling chains are bonded to the crosslinked polymer structure, and has a material shape retaining action and a wound self-healing action.

A self-healing material that is compatible, a method for producing the self-healing material, a self-healing structure in which the self-healing material is fixed to the base material soil, and the self-healing material or the self-healing structure described above And a biomedical material and an optical material. Background art

 The development of intelligent materials that mimic biomaterials is strongly desired in all fields. In particular, self-healing materials that heal spontaneously and return to their original state even when scratches occur are characteristics that are not found in conventional artificial structures, and their self-healing is strongly desired. Applications of self-healing materials include skin materials made of various materials such as materials used in places where repair work is difficult, such as outer space and the body, as well as the decline in commercial value due to surface scratches, optical materials, etc. Is the target.

 Conventionally, as self-healing materials, microcapsules and hollow fillers containing chemical reactants are mixed with specific plastic materials, and the microcapsules hollow fillers break down at the same time as scratches occur, and the internal chemical reactants. Self-healing materials based on the method of repairing damaged parts by spreading in the plastic have been proposed in, for example, the following documents 1 to 4.

 [Reference 1] R. P. Wool, Polymer Interfaces, structure and strength, p. 473, Hanser, 1995.

[Reference 2] SR White, NR Sottos, PH Geubel le, JS Moore, M. R. Kessler, SR Sriram, EN Brown, S. Viswanathan, Nature, vol. 409, pp. 794-797, (2001).

 [Document 3] E. N. Brown, S. R. White, N. R. Sottos, S. White, 'J. Mater. Sci., Vol. 39, pp. 1703-1710 (2004).

 [Reference 4] J. W. C. Pang, I. P. Bond, Composites Sci. Technol., Vol. 65, pp. 1791—1799 (2005) '.

 Further, for example, the following Non-Patent Document 5 proposes a method of paying attention to polyphenylene ether and polycarbonate, and performing self-repair by mixing a catalyst that causes a reaction again after degradation and degradation. In short, the method of Non-Patent Document 5 is a method of re-bonding the main chain of a polymer using a chemical reaction in a specific type of polymer compound.

 丄 Reference 3] K. lakeda, M. Tanahashi, H. Unno, bci. Techno 丄. Adv. Mater i als, vol. 4, pp. 435-444, (2003). A method of repairing the generated scratch by raising the temperature above the glass transition temperature is proposed in, for example, Non-Patent Document 6 below, and a method of repairing the scratch by immersing in a specific solvent is: For example, it is proposed in the following non-patent document 7 ′.

 [Ref. 6]. R. P. Wool., Polymer Interface, 'Structure and Strength, Chap. 12, Hanser Gardener, Cincinnati, 1994.

 [Reference 7] C. B. Lin, S. Lee, K. S. Liu, Polym. Eng. Sci., Vol. 30, pp. 1399-1406 (1990).

 However, in the methods of Non-Patent Document 1 to Non-Patent Document 4, it is necessary to include chemical substances in microcapsules and hollow fillers, and they must be dispersed in plastic, so that they are inferior in cost performance and technical. It is also difficult. Furthermore, it is unlikely that repeated repair of scratches on the same part of the material is expected.

Furthermore, all of the methods of Non-Patent Document 1 to Non-Patent Document 5 are applied to specific polymers. There was a problem that it was limited to compounds.

 Next, in the methods of Non-Patent Documents 6 and 7, the self-repairing action does not appear autonomously, and the material in which the scratch has occurred must be heated to a temperature higher than the glass transition temperature or immersed in a specific solvent. Therefore, it was practically difficult to apply. In addition, the method of Non-Patent Document 6 performs self-healing by using diffusion of linear polymer chains in short, thus realizing practical self-healing speed and fluidization of material (deformation of self-healing material) There is a practically fatal problem that shape collapse is directly connected to the straight. DISCLOSURE OF THE INVENTION-Due to these various problems of the prior art, 1) the manufacturing process is excellent in cost performance and technically simple, and 2 ') the object of application depends essentially on the type of polymer compound. 3) Self-healing action occurs repeatedly even in the same part of the material, 4) Self-healing action is self-healing and manifests itself without shape collapse, etc. Offer was desired. An object of the present invention is to provide such a self-healing material.

'(First invention)

 The first invention of the present application is a polymer crosslinked body in which a large number of dangling chains are bonded to the polymer crosslinked structure, and the amount of dangling chains bonded to the polymer crosslinked structure and the crosslinking point of the polymer crosslinked structure. A self-healing material that exhibits the properties of a near-critical gel that achieves both the retention of the material shape due to the high molecular cross-linking structure and the self-healing effect due to the dangling chains by adjusting the intermolecular weight within a specific region. It is.

In the self-healing material of the first invention, the material shape retention action and the self-healing action compatible. In the present specification, a crosslinked polymer having such characteristics is referred to as “near critical gel”. The holding action of the material shape is due to the above-described polymer cross-linked structure. On the other hand, the self-healing effect on the wound is due to the dangling chain. As is well known, the dangling chain means “a partial chain in which one end is connected to a crosslinked product and the other end is not connected to a crosslinked product”.

 The mechanism of self-healing action by dangling chains is that when the self-healing material is damaged, dangling chains penetrate into each other in and between the molecules of the polymer cross-linked body, and the cohesive force due to entanglement According to topology interaction. Therefore, the time required for self-healing becomes shorter at higher temperatures. However, even if the self-healing action is promoted by increasing the temperature, as long as the bonding amount of the dangling chain and the molecular weight between the crosslinking points of the polymer crosslinking structure are adjusted within a specific region, the shape of the material The holding action and the self-healing action are well balanced. This point is decisively different from the case of Non-Patent Document 6 described above.

 In conventional self-healing materials, the concept of near-critical gels for polymer cross-linked materials has never been disclosed, and moreover, the “bonding amount of dangling chains” that defines the formation of near-critical gels and “between cross-linking points” The existence of a specific region related to the “quantity” has never been disclosed or suggested. ■.

 As will be described later, the self-healing material of the first invention can be manufactured by a simple and low-cost process. Moreover, as long as it is a crosslinked polymer, its application target is not limited by the type of polymer compound. Secondly, the self-healing action is based on the above-described topological interaction, so it occurs repeatedly in the same part of the material. In addition, the self-repairing action is manifested autonomously and without shape collapse. That is, the self-healing material of the first invention can solve the above-described problems of the present invention.

Fig. 1 schematically shows the self-healing material of the first invention. In Fig. 1 (a), A single molecule of the polymer cross-linked product 1 is shown to be immobilized on the base material 3 by a chemical reaction at a fixing point 2 having a functional group. Regarding the polymer cross-linked product 1, the polymer cross-linked structure is shown. And a number of dangling chains 4 are shown visually. FIG. 1 (b) shows a state in which a plurality of molecules of the polymer crosslinked body 1 are densely fixed to the base material 3 at the fixing point 2 to form the coating layer 5. However, Fig. 1 is only a schematic illustration of a self-healing material, and specifically illustrates specific regions regarding the amount of dangling chains attached to the polymer cross-linked structure and the molecular weight between cross-linking points of the polymer cross-linked structure. It is not specified.

 In the self-healing material of the first invention, the “specific region” relating to the amount of dangling chain bonds and the molecular weight between crosslink points is the type of polymer, the type of monomer compound that forms the polymer, the polymer crosslink Because it varies depending on the contents of the structure, it is difficult or impossible to uniformly define these specific regions with numerical values. However, as will be described later in the second invention, it is possible to define a specific region that defines a near-critical gel in terms of the physical properties of the self-healing material.

(Second invention)

 In the second invention of the present application, the self-healing material according to the first invention satisfies one or more of the following conditions (a) to (d).

 (a) Loss tangent at a temperature 20 ° C higher than the glass transition temperature, which is defined as the temperature at which the loss modulus is maximum in the measurement of dynamic viscoelasticity, is in the range of 0.6 to 10.0. .

(b) Storage elastic modulus (E 20) at a temperature 20 ° C higher than the glass transition temperature, which is defined as the temperature at which the loss elastic modulus is maximized in the measurement of dynamic viscoelasticity, and storage elasticity at a temperature 80 ° C higher Ratio (E80) ratio (E20ZE 80) force within the range of 3-100 is there.

 (c) Tensile elongation at break exceeds 300%. '

 (d) The gel fraction exceeds 30%. .

 In the second invention, a specific region as a near critical gel in the self-healing material according to the first invention is defined from the viewpoint of material properties and the like.

 As will be described in detail later, a large loss tangent at a temperature higher than the glass transition temperature under the condition (a) indicates that there are many dangling chains. In the condition (b), “E 2 0 Z E 8 0” is large, that is, a large decrease in storage elastic modulus at a temperature higher than the glass transition temperature also indicates that there are many dangling chains.

 Under the condition (c), if the tensile elongation at break is 3.00% or less, the self-repairing property is not exhibited or hardly exhibited. In the condition (d), the gel fraction means [[weight after drying] / [weight before dipping] X 10 0 (%)]. The gel fraction is less than 30%, This means that there is a large amount of sol whose both ends are not connected to the frame, and in this case, the self-healing material becomes highly sticky on the surface and often causes inconvenience in handling.

(Third invention)

 In the third invention of the present application, the crosslinked polymer according to the first or second invention is a polyester resin, a polyamide resin, a polycarbonate resin, a polyurethane resin, a polyether resin, an epoxy resin, a polyimide resin, One or more of polyolefin resin, polystyrene resin, saturated rubber, unsaturated rubber, or other resin.

As mentioned above, the resin species of the crosslinked polymer constituting the self-healing material is essentially limited. Although not specified, those listed in the third invention can be preferably exemplified. The elastic modulus of the self-healing material varies depending on the selection of the resin type and the chemical structure of the polymer cross-linked body. Therefore, the elastic modulus of the surface of the self-healing material should be controlled to glass, leather, rubber, etc. Is possible.

(4th invention) ''

 According to the fourth invention of the present application, if necessary, a catalyst may be used to provide a certain first compound and a second compound or a certain first compound as defined in (1) to (3) below. A self-healing material according to any one of the first to third inventions is produced by mixing and reacting a compound to a third compound at a predetermined reaction ratio. A method for producing a self-healing material.

 (1) A first compound having three or more functional groups A in one molecule and a second compound having two or more functional groups B that specifically bind to functional group A in one molecule are functional groups AZ. The reaction ratio of the functional group B (the ratio of the number of moles of the functional group involved in the reaction: says the same shall apply hereinafter) is set to 0.3 to 0.7 and reacted.

 (2) A first compound having three or more functional groups A in one molecule, a second compound having two or more functional groups B specifically binding to the functional group A, and a functional group A. A third compound having two in one molecule is mixed and reacted at a functional group A / functional group B reaction ratio of 0.4 to 0.8. However, the number of moles of functional group A derived from the first compound occupies 25% or more of the total number of moles of functional group A.

 (3) Functional group A includes a first compound having three or more functional groups A in one molecule and a second compound having three or more functional groups B that specifically bind to functional group A in one molecule. / Reaction ratio of functional group B is 0.1 to 0.6 and mixed and reacted.

According to the fourth invention, the self-healing material according to any one of the first invention to the third invention A simple and low cost manufacturing method is provided.

 In other words, the self-healing material of the first invention which is a “near criticality gel”, as described above, it is difficult or impossible to uniformly define the specific region that defines this from the structural aspect. While it is possible to define from the viewpoint of material properties, etc. as in the second invention, it can also be defined by manufacturing conditions as in the fourth invention.

(Fifth invention)

 In the fifth invention of the present application, in (4) of the method for producing a self-healing material according to the fourth invention, the first compound has a polyisocyanate having three or more isocyanate groups as a functional group A in one molecule. In the case where the second compound is a polymer polyol having two or more hydroxyl groups in one molecule, and the self-healing material produced is a polyurethane resin, the reaction ratio of isocyanate group / hydroxyl group is 0. The first compound and the second compound are mixed and reacted as 3 to 0.7.

 The fifth invention provides an example of a particularly preferred embodiment of the polyurethane resin among the methods for producing the self-recovering material of the fourth invention. As the reaction ratio of isocyanate group / hydroxy group, a value of 0.5.5 or a value in the vicinity thereof is particularly preferred.

(Sixth invention)

 A sixth invention of the present application is a self-healing structure in which the self-healing material according to any one of the first to third inventions is immobilized on a base material.

In this sixth invention, the form of “immobilization” is not limited, but as a typical form, the molecular chain of the polymer crosslinked body constituting the self-healing material is located at one or a plurality of places. And a form chemically bonded to the substrate.

 The usage form of the self-healing material according to the first to third inventions is not limited, but as a self-healing structure in which the self-healing material is fixed on the substrate as in the sixth invention The state is particularly useful.

 The type of the substrate is not particularly limited as long as it has means capable of immobilizing the crosslinked polymer, but for example, a substrate made of a polymer material is preferably used. For the purpose of increasing the reactive functional group on the surface of the substrate, it is also preferable to perform a surface treatment such as edge discharge on the surface of the substrate. .

(Seventh invention)

 -In the seventh invention of the present application, in the self-healing structure according to the sixth invention, the elastic modulus at the use temperature of the polymer crosslinked body constituting the self-healing material is 1/10 of the elastic modulus of the substrate. And the thickness of the crosslinked polymer is 0.1 mn! Within the range of ~ 10 mm.

 If the elastic modulus of the crosslinked polymer at the operating temperature exceeds 110 of the elastic modulus of the substrate, the mechanical properties of the substrate may be greatly impaired. If the thickness of the crosslinked polymer is less than 0 ··· 1 mm, there is a problem that the scratches that are received easily reach a substrate that does not have self-healing properties. When the thickness of the crosslinked polymer exceeds 10 mm, the mechanical properties of the base material are greatly impaired, and the self-healing material tends to be wasted.

(Eighth invention)

The eighth invention of the present application is a self-healing structure in which the self-healing material according to the sixth invention or the seventh invention is used as the skin of the substrate. In this eighth invention, the meaning of “base material skin” is not limited. For example, the skin layer or coating layer of the base material, which is an inorganic or organic material, the human body or other organisms, or the body tissue separated from them. Skin layer and the like. “Skin” includes “outer skin” exposed to the outside world and “inner skin” existing in the internal space of biological or inanimate structures. '

(9th invention)

 A ninth invention of the present application is a self-healing material according to any one of the first invention to the third invention or a self-healing structure according to any of the sixth invention to the eighth invention, which is used as a biomedical material. It is a biomedical material.

 Biomedical materials can be mentioned as a particularly useful application of the above self-healing material or self-healing structure. Specific examples of biomedical materials include artificial blood vessel epidermis, artificial organ skin, and the like. (Invention 10)

 The tenth invention of the present application is a self-healing material according to any one of the first to third inventions or a self-healing structure according to any of the sixth to eighth inventions, It is an optical material that is used.

Other particularly useful applications of the above self-healing materials or self-healing structures can include optical materials. Specific examples of optical materials include lenses and resin glass. Brief Description of Drawings FIG. 1 is a diagram schematically showing the structure of the self-healing material of the present invention. FIG. 2 is a photograph showing the evaluation of the restorability of the self-healing material according to the example of the present invention. FIG. 3 is a photograph showing the evaluation of the repairability of the self-healing material according to the example of the present invention. FIG. 4 is a photograph showing the state of the repairability evaluation of the self-healing material according to the example of the present invention. FIG. 5 is a diagram showing a method for evaluating the repairability of a self-healing material according to an embodiment of the present invention. FIG. 6 is a photograph showing a state of the repairability evaluation of the self-healing material according to the example of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION;

 Next, modes for carrying out the first invention to the ninth aspect of the present application will be described including the best mode. In the following, when simply saying “the present invention”, it refers to the corresponding invention group in the first to ninth inventions. .

[Self-healing material] The self-healing material according to the present invention is a crosslinked polymer in which a number of dangling chains are bonded to the crosslinked polymer structure. In addition, the amount of dangling chains attached to the polymer cross-linked structure and the molecular weight between cross-linking points of the polymer cross-linked structure are adjusted within a certain specific region, thereby exhibiting the properties of near-critical gels. . Here, the characteristic of the near-critical gel means that the retention of the material shape and the self-healing action are compatible.) The self-healing material according to the present invention has the following (a ) ~ (D) can also be defined as satisfying one or more of the conditions.

(a) Loss tangent at a temperature 20 ° C higher than the glass transition temperature, which is defined as the temperature at which the loss modulus is maximum in the measurement of dynamic viscoelasticity, is in the range of 0.6 to 10.0. It is.

(b) Storage elastic modulus (E 2 0) at a temperature 20 ° C higher than the glass transition temperature, which is defined as the temperature at which the loss modulus is maximized in the measurement of dynamic viscoelasticity, and a temperature higher by 80 ° C The ratio (E20ZE80) of the storage elastic modulus (E80) in the range from 3 to 100.

 (c) Tensile elongation at break exceeds 300%

 (d) Gel fraction exceeds 30%.

 The above conditions (a) to (d) will be described in more detail as follows. The crosslinked polymer used in the self-healing material has a loss tangent at a temperature 20 ° C. higher than the glass transition temperature in the range of 0.6 to 10.0, more preferably in the range of 0.65 to 5.0. Of these, more preferably in the range of 0.7 to 3.0. If the loss tangent at this temperature is less than 0.6, self-healing is not exhibited, and if it exceeds 10.0, it is difficult to maintain the shape.

 Also, the loss tangent at a temperature 50 ° C. higher than the glass transition temperature is in the range of 0.3 to 10.'0, more preferably in the range of 0.5 to 30. Further excellent self-repair. It is preferable to show the property. The polymer cross-linked product has a higher temperature than the glass transition temperature and a large loss tangent at temperature. This means that one end is connected to the cross-linked product and the other end is not connected to the cross-linked product (dangling chain). Is called). Since the dangling strand shows entanglement and interaction with other adjacent dangling strands, once it is cleaved, it shows repair properties by entanglement interaction again.

 The glass transition degree in the present invention means a temperature defined as a temperature at which the tensile loss elastic modulus is maximum in the measurement of dynamic viscoelasticity, and is measured by a commercially available forced vibration type dynamic viscoelasticity measuring device. It is possible to measure easily.

The crosslinked polymer used in the self-healing material of the present invention has a ratio between the storage elastic modulus (E20) at a temperature 20 ° C. higher than the glass transition temperature and the storage elastic modulus (E 80) at a temperature higher than 80 ° C. “E 20ZE 80” is in the range of 3 to: 100, more preferably Is in the range of 8 to 80. If E 2 0 / E 80 is less than 3, self-repairing properties are not exhibited, and if it exceeds 100, it is difficult to maintain the shape.

 A large decrease in storage modulus at a temperature higher than the glass transition temperature means that there are many dangling chains. The dangling strand exhibits a repair property to the wound due to the above-described action. However, if the storage elastic modulus decreases too much, the temperature dependence of the elastic modulus becomes excessive, which may cause practical problems.

 The polymer frame used in the self-healing material of the present invention has a tensile elongation at break exceeding 300%. If the tensile elongation at break is 300% or less, self-healing is not exhibited. High elongation of the polymer crosslinked body generally means that the molecular weight between crosslinks is large. Cross-linked product with large molecular weight between cross-linking points The cross-linking density is low, and tangling interaction between the dangling chain and the cross-linked chain (partial chain where both ends are connected to the cross-linked product) also occurs. Therefore, self-healing properties are even better. '

 The crosslinked polymer used in the self-healing material of the present invention has a gel fraction [[weight after drying] g [weight before dipping] X 10 0 (%)] of 30%, more preferably 5%. It is desirable to exceed 0%, more preferably 80%. When the gel fraction is less than 30%, the surface tackiness becomes violent, which often causes inconvenience in handling.

 The low gel fraction of the polymer cross-linked product means that the amount of sol whose both ends are not connected to the cross-linked product increases. The sol component causes surface stickiness, making it difficult to use as a material.

In addition, the crosslinked polymer used in the self-healing material of the present invention has an equilibrium swelling degree (([weight after swelling] −1 [weight after drying]) of the gel contained in the crosslinked body in acetone. / [Weight after drying]) is 2 or more, preferably 5 or more at room temperature, which makes the self-repairing property remarkable. When the equilibrium swelling degree of the crosslinked polymer is large, the molecular weight between the crosslinking points becomes large. If the molecular weight between crosslinks is large, the crosslink density of the crosslinked product is low.

Self-repairability is excellent because entanglement and interaction occur with (a partial chain in which both ends are connected to a crosslinked product). .

 Furthermore, the polymer crosslinked product used in the self-healing material of the present invention has a glass transition temperature defined as a temperature at which the tensile loss elastic modulus at a frequency of 10 Hz is maximized in the measurement of dynamic viscosity. It is desirable that the temperature is not higher than 20 ° C., which increases the repair speed. . ''

 The self-healing behavior in the self-healing material of the present invention is due to entanglement interaction involving dangling chains. The time until the entanglement interaction is formed depends on the diffusion rate of the molecule, and since the diffusion rate becomes extremely small below the glass transition temperature, self-healing properties are not shown in practice.

 The resin type of the self-healing material is not limited as long as it can form a polymer cross-linked body, but since the control of the reaction is easy, polyester resin, polyamide resin, polycarbonate resin, polyurethane resin, poly It is preferably composed of one or more of ether resin, epoxy resin, polyimide resin, polyolefin resin, polystyrene resin, saturated rubber and unsaturated rubber. In addition, blend materials of these self-healing materials and other types of materials that are not self-healing materials (resin rubber) may be used.

 [Method of manufacturing self-healing material]

The self-healing material of the present invention can be produced by the method of the fourth invention. That is, if necessary, using a catalyst, a certain first compound and second compound, or certain first compound to third compound, as defined in (1) to (3) below. Predetermined This is a method for producing the self-healing material described above by mixing and reacting at the reaction ratio (the ratio of the number of moles of functional groups involved in the reaction; the same shall apply hereinafter).

 (1) Functional group A includes a first compound having three or more functional groups A in one molecule and a second compound having two or more functional groups B that specifically bind to functional group A in one molecule. / Reaction ratio of functional group B is 0.3 to 0.7 'and mixed and reacted.

 (2) A first compound having three or more functional groups A in one molecule, a second compound having two or more functional groups B specifically binding to the functional group A, and a functional group A. .1 A third compound having two in a molecule is mixed and reacted at a reaction ratio of functional group A and functional group B ′ of 0.4 to 0.8. However, the number of moles of functional group A derived from the first compound occupies 25% or more of the total number of moles of functional group A.

 (3) A functional group AZ comprising a first compound having three or more functional groups A in one molecule and a second compound having three or more functional groups B specifically binding to the functional group A in one molecule. The reaction ratio of functional group B! Mix and react as ~ 0.6.

In this method, the first compound to the third compound mean so-called monomers. The functional group AZ functional group B can be combined with the isocyanate group Z hydroxyl group, isocyanate group Z amino group, carboxyl group / amino group, carboxyl group hydroxyl group, carboxyl group Z glycidyl group, carboxyl group oxazoline group, maleic anhydride Examples include oxazoline group, maleic anhydride nomino group, glycidyl group Z oxazoline group, isocyanate group Z oxazoline group and the like. As the “catalyst to be used when necessary”, those well known in the polymerization reaction system of the first compound to the third compound may be appropriately selected and used. For example, dibutyltin dilaurate is widely used in polyurethane polymerization systems, and titanium compounds are widely used in polyester polymerization systems. From the viewpoint of the advantage in the manufacturing method of the self-healing material, polyurethane resin is particularly preferable because it is easy to handle. In particular, as described above in the fifth invention, a polyurethane-based resin obtained from a polyisocyanate compound having three or more isocyanate groups in one molecule and a polymer polyol having two or more hydroxyl groups in one molecule is provided. The raw material has low toxicity and is preferable because of excellent handling.

 Examples of isocyanate compounds having 3 or more isocyanate groups include 2, 4- and 2, 6-tolylene diisocyanate, m- and p-phenylene diisocyanate, , 4-Diisocyanate, 1,5-Naphtalene diisocyanate, Methylenebisphenylene 4,4'-Diisocyanate, m- and p-xylene diisocyanate, Hexamethylene diisocyanate, Lysine diisocyanate, 4, 4 , Monomethylene biscyclohexyl diisocyanate, isophorone diisocyanate, trisodium diisocyanate trimer such as trimethylhexamethylene diisocyanate, 1, 6, 11-undecane diisocyanate, lysine ester Rudriisocyanate, 4-isocyanate methyl-1,8-octamethinoresinisocyanate, etc. Toriisoshiane one DOO such or polyphenyl methane polyisobutylene Xia Ne - multifunctional Isoshianeto such as bets and the like, one or more of these can be used.

 Also, the above diisocyanates can be used in combination. However, in this case, it is desirable that the number of N CO groups in the triisocyanate is 0.25 or more with respect to the number of N CO groups in all isocyanates. If it is less than 0.25, the shape may not be retained due to insufficient crosslinking density.

Polymer polyols having two or more hydroxyl groups in one molecule include polyester polyols, polyether polyols, polycarbonate polyols, Bran oil-based polyols, saponified EVA (ethylene vinyl acetate copolymer), polyvinyl alcohol, cellulose and cellulose derivatives are used, and one or more of these are used.

 The molar ratio of the NCO group and hydroxyl group of the isocyanate compound to be used is within the range of 0.3 to 0.7, more preferably 0.4 to 0.6 when the number of hydroxyl groups in the polymer polyol is two. It is within the range. If this molar ratio is less than 0.3, even if triisocyanate alone is used as the isocyanate, the shape may not be retained due to insufficient crosslinking density, and if it exceeds 0.7, the self-repairing property may not be exhibited. '"[Self-healing structure]

 The self-healing structure of the present invention is one in which any of the above self-healing materials is immobilized on a substrate. In this case, the self-healing material can be preferably used, for example, as the skin of the substrate.

 The type of the base material of the self-healing structure is not particularly limited as long as it has a means capable of immobilizing the crosslinked polymer constituting the self-healing material by chemical bonding or the like. In the case of immobilizing a high-molecular crosslinked product by chemical bonding, it is necessary to have a functional group that generates chemical bonding, and a polymer material substrate is preferably used. As the base material of the polymer material, for example, polyester resins, polyamide resins, cellulose and cellulose derivatives, polyurethane resins, polycarbonate resins, polyether resins, polyimide resins, various rubbers and the like are preferably used.

In addition, the surface of the above plastic and rubber base materials subjected to corona discharge treatment for the purpose of increasing reactive functional groups on the surface, and also the surface of polyolefin resin, polychlorinated bur resin, polystyrene resin, acrylic resin It is also possible to use one that has been subjected to corona discharge treatment. In the self-healing structure: The elastic modulus of the polymer crosslinked body at the operating temperature is 10% or less of the base material's raw material, and the thickness of the polymer crosslinked body is 0.1 mm to It is preferably within the range of 10 mm If the elastic modulus of the crosslinked polymer exceeds 1/10 of the elastic modulus of the base material, the mechanical properties of the base material may be greatly impaired. If the thickness of the molecular cross-linked body is less than 0.1 mm, scratches on the surface may reach the base material that does not exhibit self-healing properties. If exceeded, the chemical properties of the base material will be greatly impaired, and the material will be wasted and there is a strong risk of inferior cost performance.

 The polymer cross-linked product before chemically bonding to the base tree or the self-repairing structure chemically bonded to the base material and the polymer cross-linked product is once immersed in an excess organic solvent and included in the polymer cross-linked product. It is also possible to dissolve the sol component in the solvent. By treating with an organic solvent, the surface tackiness can be reduced.

 The self-healing material of the present invention can be preferably used, for example, as a high-grade skin material that dislikes surface scratches, an optical material, and a member that is not easily exchangeable, such as a biomedical material.

 Based on the various embodiments described above, the self-healing material of the present invention has the following advantages: 1) The manufacturing process is excellent in cost performance and technically simple, and 2) The application target is essentially limited by the type of polymer compound. 3) Self-healing action is repeated even in the same part of the material, and 4) Self-healing action is exhibited autonomously and without shape collapse etc. Can do. Example

Examples of the present invention and comparative examples will be described below. The technical scope of the present invention includes these It is not restricted by the examples and comparative examples.

 [Measurements in Examples and Comparative Examples]

 1) Measurement of storage modulus and loss tangent.

 The storage elastic modulus and loss tangent of the polymer crosslinked body and the substrate were measured in a linear region using a forced vibration type dynamic viscoelasticity measuring apparatus (UBM, E-4000). The measurement frequency was 10 Hz, the temperature increase rate was 2 ° C / min, and a sine wave was applied to perform the measurement in tensile mode. The glass transition temperature was a temperature at which the loss elastic modulus was maximum in the glass-rubber transition region. Loss tangent (ta η δ) at temperatures 20 ° C and 50 ° C higher than the glass transition temperature, and the ratio of storage modulus at temperatures 20 ° C and 80 ° C higher than the glass transition temperature [Ε (20) Ε (80)], the elastic modulus ratio between the substrate and the crosslinked product at room temperature was determined.

 2) Measurement of tensile elongation at break

 The crosslinked polymer was stretched by a uniaxial tensile test. The tensile speed was 5 OmmZ and the elongation at the breaking point was measured. .

 3) Measurement of gel fraction and degree of swelling

 The polymer cross-linked product whose weight was measured in advance was immersed in an excess of acetone and left at room temperature for 24 hours. The weight of the swollen crosslinked product was measured, and then the solvent was removed by vacuum drying to measure the dry weight. [Weight after drying] / [Weight before immersion] XI 0-0 (%) as the gel fraction, [([weight after swelling] 1 [weight after drying]) / [weight after drying] ] Was determined as the degree of swelling.

 4) Evaluation of self-repairability

Using a razor, a 0.5 mm deep cut was made on the sample in which the polymer cross-linked product was bonded to the substrate. The cut length was 5 mm. Left at room temperature for 24 hours Later, the degree of repair of the scratch was visually confirmed.

 5) Evaluation of shape retention

 Using a sample in which the polymer crosslinked body was bonded to the substrate, the substrate was left for one week with the substrate facing upward and the crosslinked body facing downward, and the surface condition was visually observed.

 6) Evaluation of surface adhesion

 Surface tack was evaluated by touching a sample with polymer cross-linked to the substrate with a finger. If the adhesive component remains on the finger after separation from the sample, it was marked as “Surface adhesive”. '..

 〔Example .

 Polymer polyol (manufactured by Nippon Polyurethane Co., Ltd., trade name NIPPOLAN 1 52, number average molecular weight 2 0 0 0) and hexamethylene diisocyanate trimer (manufactured by Nippon Polyuretan Co., Ltd., trade name Coronate HX ) Was mixed at a reaction ratio of [NCO] / [OH] of 0.55, and further dibutyltin dilaurate (100 ppm) was mixed as a catalyst. 'After defoaming with a vacuum dryer at room temperature, pour it over a polyethylene terephthalate base material that has been partially corona-treated: 1 hour at 5 ° C for 5 minutes to perform urethane reaction Got. ,

 The thickness of the crosslinked product was 1 mm. Self-healing properties were evaluated using the obtained samples. For the purpose of producing a crosslinked product for measuring physical properties, the defoamed mixed sample was poured onto polytetrafluoroethylene and heated at 150 ° C. for 5 minutes to carry out a urethane reaction. The obtained crosslinked product was peeled from polytetrafluoroethylene, and various physical properties were measured.

 Example 2

Crosslinked urethane on polyethylene terephthalate substrate in the same manner as in Example 1. After that, it was immersed in a large amount of acetone and allowed to stand at room temperature for 8 hours. Thereafter, the solvent was removed by vacuum drying to prepare a sample. Self-healing properties were evaluated using the obtained samples. The crosslinked product obtained by the same method as in Example 1 was peeled from polytetrafluoroethylene, immersed in a large amount of acetone and allowed to stand at room temperature for 8 hours, and then the solvent was removed by vacuum drying. Thus, a crosslinked product for measuring physical properties was obtained.

 [Comparative Example 1].

 Polymer polyol (manufactured by Nippon Polyurethane Co., Ltd., trade name NIPPONLAN 1 52 number average molecular weight 2000) and hexamethylene diisocyanate trimer (manufactured by Nippon Polyuretan Co., Ltd., trade name Coronet HX) A sample was obtained in exactly the same manner as in Example 1 except that the [NCO] / '[OH] reaction ratio was 1.0, and various measurements were performed. ,

(Comparative Example 2)

 Poly, polyol (Nippon Polyurethane Co., Ltd., trade name NIPPOLAN 152 number average molecular weight 2.000) and hexamethylene diisocyanate trimer (Nippon Polyuretan Co., Ltd., trade name Coronate HX) [NCO] Samples were obtained in exactly the same manner as in Example 1, except that the reaction ratio was set to 0.28 in the reaction ratio of / [OH], and various measurements were performed.

 [Evaluation results of Example 1 2 and Comparative Example 1 2]

The evaluation results of various measurements in Examples 12 and Comparative Example 12 described above are shown in Table 1 below.

*1 自己修復性 O 自己修復； X 自己修復しない 一

* 1 Self-healing O Self-healing; X Does not self-healing

 * 2 Shape holdability Can be used to hold the O ^ shape: Cannot be used because it flows without holding the X shape

 * 3 Surface tackiness O No tackiness Δ Slightly tacky: Severely sticky

* 4 Cannot be measured because it is not solid.

Example 3

 A crosslinked product for measuring physical properties was obtained in the same manner as in Example 2 except that the reaction ratio of [NC 0] [OH] was 0 · 60. .

 Example 4

 Polymer Polyolene [Nippon Polyurethane Co., Ltd., trade name-Zuporan 152, number average molecular weight 2000] 33.8 g and hexamethylene diisocyanate (Aldrich) 1. 46 g, dibutyltin dilaurate 10 O p The new polymer polyol was obtained by mixing pm, mixing while maintaining at about 90 ° C. in a water bath and reacting for 20 minutes. A crosslinked product for measuring physical properties was obtained in the same manner as in Example 2 except that the newly obtained polymer polyol and polyisocyanate were adjusted to a reaction ratio of [NCO] / [OH] of 0.50.

 The state of self-healing of the scratches given to the crosslinked body according to Example 4 (the self-healing material of the present invention) is shown by the photographs in FIGS. Fig. 2 shows a state where a cut (completely cut state) has been given, Fig. 3 shows a state immediately after joining the cut portion (the cut remains), and Fig. 4 shows a condition for 24 hours at room temperature. This shows the state in which the cut after self-healing is completely self-healing.

 [Evaluation results of Examples 3 and 4]

 The evaluation results of various measurements in Examples 3 and 4 described above are shown below. The notation method of the evaluation results is the same as in Table 1 above.

 (Evaluation result of Example 3)

 Reaction ratio: 0.60

 Elastic modulus ratio: 9.6

Glass transition temperature: _43 tan δ (Tg + 20): 0.70 tan δ (Tg + 50): 0.51 Gel fraction: 100 'Swelling degree: 5.1 Ratio of elastic modulus to base material':> 100 Tensile elongation. ': > 300 Self-healing: 〇 Shape retention: 〇 Surface adhesion: o

; Evaluation result of Example 4) Reaction ratio: 0.50 Elastic modulus ratio: 49.8 Gala, s transition temperature: -48 tan 6 (Tg + 20): 0.86 tan δ (Tg + 50): 0. 78 Gel fraction:: 100 Swelling degree: 12.5 Elastic modulus ratio with base material:> 100 Tensile elongation:> 300 Self-healing property: 〇 Shape retention: 〇 Surface adhesiveness: 〇

Example 5 A film of self-healing material with a thickness of 2 mm and a width of 2 O mm was obtained under the same conditions and process as in Example 1 except that the reaction ratio of [NCO] / [OH] was 1.0. Sample (Sample A) was obtained. Further, under the same conditions and process as in Example 1 except that the reaction ratio of [NCO] / [OH] was 0.5, a film-like self-healing material having a thickness of 2 mm and a width of 2 O mm was used. A sample (Sample B) was obtained.

 As shown in Fig. 5, these 'film-like samples 1 are placed on a cylindrical column 2 with a diameter of 12 mm so that it bends and hangs under its own weight, and a laser blade is used along the chain line shown in the figure. A cut with a width of 2 O mm and a depth of approximately 2 mm was made. After that, it was immediately removed from the cylindrical column, allowed to stand for 10 minutes without receiving external force at room temperature, and then returned to the mounting state shown in FIG. The change over time of the cut of the film-like sample 1 in this state is shown in FIG. 6 by an enlarged photograph from the arrow “top view” direction and an enlarged photograph from the arrow “side view” direction shown in FIG.

 The photographs shown as “top view” and “side view” in “A” in FIG. 6 are photographs immediately after the left side of the above sample A is returned to the mounting state shown in FIG. 5, and the right side is It is a photograph after 10 minutes have passed in that state. Similarly, the photographs shown as “top vi6w” and “side view” in “BJ” in FIG. 6 are the photographs immediately after the left side of the sample B is returned to the mounting state shown in FIG. Yes, the photo on the right is 10 minutes after it has been in that condition.

 As can be seen from Fig. 6, in sample A shown in the photograph of "A", the cut is not repaired even after 10 minutes. In the sample B shown in the photograph of “B”, the cut is repaired in a very short time of 10 minutes against the load to expand the cut based on the weight of the sample. Industrial application fields

 According to the present invention, a self-healing material having various advantages over the prior art and a self-healing structure using the material can be manufactured easily and at low cost.

Claims

The scope of the claims 1. A polymer structure in which a large number of dangling chains are bonded to the polymer cross-linked structure, and the amount of dangling chains bonded to the polymer cross-linked structure and the cross-link of the polymer cross-linked structure. A self-healing material that exhibits the properties of a near-critical gel that achieves both the retention of the shape of the material and the self-healing action by adjusting the molecular weight within a specific region.  2. The self-healing material according to claim 1, wherein the self-healing material satisfies one or more of the following conditions (a) to (d).  (a) The loss tangent at a temperature 20 ° C. higher than the glass transition temperature, which is defined as the temperature at which the loss modulus is maximum in the measurement of dynamic viscoelasticity, is in the range of 0.6 to 10.0.  (b) Storage elastic modulus (E20) at a temperature 20 ° C higher than the glass transition temperature, which is defined as the temperature at which the loss modulus is maximum in the measurement of dynamic viscoelasticity, and storage elasticity at a temperature 80 ° C higher. Ratio of ratio (E80) (E20ZE80), 3 to: Within the range of 100. :,.  (c) Tensile elongation at break exceeds 300%. '  (d) The gel fraction exceeds 30%.  3. The polymer cross-linked product is polyester resin, polyamide resin, polycarbonate resin, polyurethane resin, polyether resin, epoxy resin, polyimide resin, polyolefin resin, polystyrene resin, saturated rubber, unsaturated type ^ The self-healing material according to claim 1 or 2, which is made of a blend material with one or more types of rubber, or other types of resin rubber.  4. If necessary, use a catalyst to place certain first and second compounds or certain first to third compounds as specified in (1) to (3) below. A method for producing a self-healing material, wherein the self-healing material according to any one of claims 1 to 3 is produced by mixing and reacting at a constant reaction ratio. (1) A first compound having 3 or more functional groups A in a molecule and a specific bond to functional group A A second compound having two or more functional groups B to be combined in one molecule is mixed and reacted at a reaction ratio of functional group AZ functional group B of 0.3 to 0.7.  '(2) A first compound having 3 or more functional groups A in one molecule, a second compound having 2 or more functional groups B specifically binding to functional group A, and a functional group A third compound having two A atoms in one molecule is mixed and reacted at a reaction ratio of functional group AZ functional group B of 0.4 to 0.8. However, the number of moles of the functional group A derived from the first compound occupies 25% or more of the total number of moles of the functional group A. ,  (3) A functional group comprising a first compound having three or more functional groups A in one molecule and a second compound having three or more functional groups B specifically binding to functional group A in one molecule. The reaction ratio of the AZ functional group B is set as 0.  5. In (1), the first compound is a polyisocyanate compound having three or more isocyanate groups as functional group A in one molecule, and the second compound has two or more hydroxyl groups in one molecule. When the self-healing material to be produced is a polymer resin and is a polyurethane resin, the first compound and the second compound are mixed and reacted at a reaction ratio of the isocyanate group hydroxyl group of 0.3 to 0.7. 5. A method for producing a self-healing material according to item 4 of 1.  • 6. A self-healing structure in which the self-healing material according to any one of claims 1 to 3 is immobilized on a substrate.  7. The use of the polymer crosslinked material constituting the self-healing material in the self-healing structure has an elastic modulus at a working temperature of 10 to 10 or less of the elastic modulus of the base material, and a polymer bridge The self-repairing and recovering structure according to claim 6, wherein the thickness of the body is in the range of 0.1 mm to 10 mm. ''  8. The self-healing structure according to claim 6 or 7, wherein the self-healing material is used as a skin of the base material.  9. The self-healing material according to any one of claims 1 to 3 or the self-healing structure according to any one of claims 6 to 8, which is used as a biomedical material. Biomedical material that is. 1 0. Self-healing material according to any one of claims 1 to 3 or claim 9. An optical material that is a self-repairing structure according to any one of items 6 to 8, which is used as an optical material.