Novel base plate and processing technology thereof

Abstract

The invention relates to the technical field of polymer functional materials, and discloses a novel base plate and a processing technology thereof.The base material of the base plate is composed of furan functionalized polyurethane and bismaleimide which are cross-linked through a reversible Diels-Alder reaction, and a formed dynamic covalent network enables the base plate to have the thermally-induced self-repairing capacity; latent temperature-sensitive dye and latent photoluminescence molecules are uniformly dispersed in the matrix at the same time. The processing technology comprises the steps that the components are subjected to melt blending and compression molding to form a base plate biscuit, then ultraviolet light with the specific wavelength is used for selectively irradiating a preset area of the biscuit, and functional writing is completed. In the illumination step, latent functional molecules are activated in situ in the material, so that irreversible chemical structure transformation occurs on the latent functional molecules, and therefore, the high-wear-resistance embedded identifier with temperature-sensitive warning and light-induced verification functions is formed. The technical problems that a traditional base plate mark is prone to abrasion, single in function and incapable of being repaired after being damaged are solved.

Description

Technical Field

[0001] This invention relates to the field of polymer functional materials technology, specifically to a novel pad and its processing technology. Background Technology

[0002] In various fields such as industrial production, laboratory operations, and daily applications, mats are widely used as a basic functional component, typically serving as platforms for cutting, cushioning, support, or load-bearing. The base material of these mats is mostly traditional polymer materials such as polyethylene, polypropylene, or conventional polyurethane. To meet specific usage requirements, such as labeling safety warnings, operating procedures, brand logos, or anti-counterfeiting information, information labeling is usually required on the mats.

[0003] Currently, the mainstream technologies for information labeling focus on surface treatment processes, such as screen printing, inkjet printing, or creating patterns through laser engraving and mechanical etching on the substrate surface. However, because the substrate inevitably undergoes repeated friction, wear, chemical contact, and physical impact during use, these labeling methods, which rely entirely on surface adhesion or changes in surface structure, inherently suffer from insufficient durability in the resulting patterns or text. Blurring, wear, or even complete disappearance of the labeling can not only lead to the loss of critical safety information but also affect product traceability and verification.

[0004] Furthermore, the materials used in existing pads are relatively simple in function, typically providing only basic physical support or protection. Their matrix lacks inherent properties to respond to and warn of external environmental changes (such as temperature), and also lacks self-healing capabilities in the face of physical damage. Once scratches or breaks occur on the pad surface, the damage is permanent, affecting not only its performance and aesthetics but also directly shortening its effective lifespan, increasing replacement frequency, and resource consumption. Therefore, existing technologies have significant shortcomings in providing pads that combine highly durable functional markings with self-healing matrix capabilities. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a novel pad and its processing technology, which solves the problems of traditional pads whose functional markings are prone to wear and failure due to reliance on surface treatment, whose functions are limited and lack intrinsic temperature-sensitive warning and photosensitive verification characteristics, and whose base material cannot repair itself after damage, thus limiting its service life.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a novel pad and its processing technology.

[0007] The first aspect of this invention provides a novel pad, said pad being made of a composite elastomer material, the composition of which, by mass percentage, is:

[0008] Dynamically cross-linked self-healing elastomer matrix: 85.0%-95.0%;

[0009] Crosslinking agent: 4.0%-10.0%;

[0010] Latent molecular-level thermosensitive dyes: 0.1%-1.0%;

[0011] Latent photoluminescent molecules: 0.1%-1.0%.

[0012] In one specific embodiment, the dynamically crosslinked self-healing elastomer matrix is ​​a furan-functionalized dynamically crosslinked polyurethane prepolymer. This matrix serves as the structural main body of the pad, and the furan groups contained in its polymer chains can undergo a reversible Diels-Alder reaction with the double bonds of the crosslinking agent under specific conditions to form a dynamic crosslinked network, thereby endowing the material with the ability to self-repair after physical damage.

[0013] In one specific embodiment, the crosslinking agent is 1,1'-(methylenedi-4,1-phenylene)bismaleimide, in which the maleimide group in its molecular structure acts as a dienophile and interacts with the furan group in the dynamically crosslinked self-healing elastomer matrix to form a covalent crosslink.

[0014] In one specific embodiment, the latent molecular-level thermosensitive dye is a spiropyran derivative. In its latent state (i.e., before activation by specific energy light), this derivative has a closed-ring spiropyran structure, with no conjugation effect and no color response to temperature changes. When activated by light energy of a specific wavelength, its molecular structure undergoes an irreversible change, forming a heat-sensitive system. In this activated state, when the ambient temperature is below a preset threshold, the molecule maintains a colorless or specific color closed-ring structure; when the ambient temperature rises and exceeds the preset threshold, the molecule undergoes a thermo-induced isomerization reaction, opening the ring to form a cyanine structure with a large conjugated system, thus exhibiting a significant and irreversible color change.

[0015] In one specific embodiment, the latent photoluminescent molecule is a 2-nitrobenzyl-protected coumarin derivative. In its latent state, the activity of its luminescent group (coumarin) is shielded by the photosensitive protecting group 2-nitrobenzyl, thus preventing fluorescence under excitation. When irradiated with light of the same wavelength as that activating the latent molecular-level thermosensitive dye, the 2-nitrobenzyl group undergoes photolytic degradation and detaches, releasing photoluminescent coumarin molecules. The released coumarin molecules emit fluorescence of a specific color under specific excitation light.

[0016] One of the core technical concepts of this invention lies in the fact that the pad is divided into functionalized and non-functionalized regions. In the functionalized regions, both the latent molecular-level thermosensitive dye and the latent photoluminescent molecule are converted into an activated state, possessing both thermosensitive response and photoluminescence functions. In the non-functionalized regions, both molecules retain their original latent state and do not possess the aforementioned functions.

[0017] A second aspect of the present invention provides a novel processing method for a pad, the process comprising the following steps:

[0018] S1, Blending: A homogeneous composite material is prepared by melt blending a dynamically cross-linked self-healing elastomer matrix, a cross-linking agent, a latent molecular-level thermosensitive dye, and a latent photoluminescent molecule in a predetermined mass percentage. In a specific embodiment, the melt blending temperature range is 110-140℃.

[0019] S2, Molding: The composite material is placed in a mold and compression molded at a temperature of 120-150℃ and a pressure of 10-20MPa. During this process, the dynamically cross-linked self-healing elastomer matrix undergoes a cross-linking reaction with the cross-linking agent. After molding, a blank pad with its overall function in a latent state is obtained. In a specific embodiment, the heat and pressure holding time during the compression molding process is 15-30 minutes.

[0020] S3, Functionalization Writing: A light source with a center wavelength of 360-375nm is used to selectively irradiate one or more pre-defined patterned areas on the surface of the raw substrate. The irradiation energy causes latent molecular-level thermosensitive dyes and latent photoluminescent molecules within the pre-defined patterned areas to undergo simultaneous photochemical reactions, transforming them into an activated state. In contrast, in areas not irradiated by light, the two types of molecules remain in a latent state. Thus, a functionalized region consistent with the pre-defined pattern is formed on the substrate material. In a specific embodiment, the irradiation energy density is 500-2000 mJ / cm². 2 .

[0021] In a preferred embodiment, the selective illumination in S3 is specifically achieved by: using a digital light processing system to load a digital mask file containing the preset pattern into the system; using a digital micromirror device built into the system to spatially modulate the light beam emitted by the light source to form a light field that precisely corresponds to the preset pattern; and finally projecting the light field onto the surface of the blank plate.

[0022] This invention provides a novel pad and its processing technology. It has the following beneficial effects:

[0023] 1. This invention employs selective illumination to simultaneously induce a photochemical reaction between latent molecular-level thermosensitive dyes and latent photoluminescent molecules within a pre-defined pattern area on the pad material. This process infuses pattern information into the material matrix through changes in its intrinsic molecular structure. The resulting pattern and pad substrate become an inseparable whole, solving the technical problems of stress concentration caused by physical engraving or pattern wear and detachment caused by surface printing in existing technologies, thus improving the durability of the markings.

[0024] 2. This invention combines latent molecular-level thermosensitive dyes and latent photoluminescent molecules in a material and simultaneously activates them using the same selective illumination step. This results in a pre-defined pattern area that integrates both thermosensitive warning and photoluminescent verification functions. This structure expands the original single marking function into a multifunctional carrier that integrates information display, status monitoring, and authenticity verification, thus improving the functional integration of the pad.

[0025] 3. This invention utilizes furan-functionalized dynamically crosslinked polyurethane prepolymer as the matrix for the dynamically crosslinked self-healing elastomer, and reacts it with a bismaleimide crosslinking agent to construct a crosslinked network containing reversible Diels-Alder reaction chemical bonds. This network allows the broken chemical bonds of the pad material to reform after being damaged by scratches or other abrasions, thereby endowing the pad with overall self-healing capabilities and extending the product's intact appearance and service life. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to embodiments, comparative examples, and test examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Main ingredients:

[0028] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0029] Isophorone diisocyanate, CAS: 4098-71-9;

[0030] Polytetrahydrofuran diol, CAS: 25190-06-1;

[0031] Furfuryl alcohol: CAS: 98-00-0;

[0032] 1,3,3-Trimethyl-2-methyleneindoline: CAS: 118-12-7;

[0033] 5-Nitrosalicylaldehyde: CAS: 97-51-8;

[0034] 4-Methylumbelliferone: CAS: 90-33-5;

[0035] 2-Nitrobenzyl bromide: CAS: 3958-60-9;

[0036] Potassium carbonate: CAS: 584-08-7;

[0037] Tetrahydrofuran: CAS: 109-99-9;

[0038] N,N-Dimethylformamide: CAS: 68-12-2;

[0039] Methanol: CAS: 67-56-1;

[0040] Ethyl acetate: CAS: 141-78-6;

[0041] n-Hexane: CAS: 110-54-3.

[0042] Examples 1-4:

[0043] Example 1:

[0044] Composite material preparation:

[0045] Weigh the following components by mass percentage: 90.0% of the furan-functionalized dynamically crosslinked polyurethane prepolymer prepared in the raw material preparation section, 8.5% of 1,1'-(methylenedi-4,1-phenylene)bismaleimide, 0.5% of the spiropyran derivative prepared in the raw material preparation section, and 1.0% of the 2-nitrobenzyl-protected coumarin derivative prepared in the raw material preparation section. Melt-blend the above components in a twin-screw extruder at 110°C, and then pelletize to obtain composite material particles.

[0046] Pad preparation and functionalization:

[0047] A suitable amount of composite material particles were placed in a mold and molded at 115℃ and 12MPa for 10 minutes. After cooling to 50℃, the mold was opened to obtain a blank of the molded pad. The blank of the molded pad was placed on the worktable of a digital light processing system, and a preset pattern digital mask file was loaded. A light intensity of 360nm and an illumination energy density of 450mJ / cm² was used. 2 The surface of the blank is selectively exposed to ultraviolet light to complete the functional writing, thus obtaining the novel blank of Example 1.

[0048] Example 2:

[0049] Composite material preparation:

[0050] Weigh out the following components by weight percentage: 88.0% of the furan-functionalized dynamically crosslinked polyurethane prepolymer prepared in Example 1, 10.0% of 1,1'-(methylenedi-4,1-phenylene)bismaleimide, 1.0% of the spiropyran derivative prepared in Example 1, and 1.0% of the 2-nitrobenzyl-protected coumarin derivative prepared in Example 1. Melt-blend the above components in a twin-screw extruder at 110°C, and pelletize to obtain composite material particles.

[0051] Pad preparation and functionalization:

[0052] A suitable amount of composite material particles were placed in a mold and molded at 120℃ and 10MPa for 15 minutes. After cooling to 50℃, the mold was opened to obtain a blank of the molded pad. The blank of the molded pad was placed on the worktable of the digital light processing system, and a preset pattern digital mask file was loaded. An illumination energy density of 500mJ / cm² was used. 2 The surface of the blank of the pad is selectively exposed to ultraviolet light to complete the functional writing, thus obtaining the new pad of Example 2.

[0053] Example 3:

[0054] Composite material preparation:

[0055] Weigh the following components by weight percentage: 95.0% of the furan-functionalized dynamically crosslinked polyurethane prepolymer prepared in Example 1, 4.8% of 1,1'-(methylenedi-4,1-phenylene)bismaleimide, 0.1% of the spiropyran derivative prepared in Example 1, and 0.1% of the 2-nitrobenzyl-protected coumarin derivative prepared in Example 1. Melt-blend the above components in a twin-screw extruder at 140°C, and pelletize to obtain composite material particles.

[0056] Pad preparation and functionalization:

[0057] A suitable amount of composite material particles were placed in a mold and molded at 150℃ and 20MPa for 30 minutes. After cooling to 50℃, the mold was opened to obtain a blank of the molded pad. The blank of the molded pad was placed on the worktable of the digital light processing system, and a preset pattern digital mask file was loaded. A light irradiation energy density of 2000 mJ / cm² was used with a center wavelength of 375nm. 2 The surface of the blank pad is selectively exposed to ultraviolet light to complete the functional writing, thus obtaining the novel pad of Example 3.

[0058] Example 4:

[0059] Composite material preparation:

[0060] Weigh the following components by weight percentage: 92.0% of the furan-functionalized dynamically crosslinked polyurethane prepolymer prepared in Example 1, 7.0% of 1,1'-(methylenedi-4,1-phenylene)bismaleimide, 0.5% of the spiropyran derivative prepared in Example 1, and 0.5% of the 2-nitrobenzyl-protected coumarin derivative prepared in Example 1. Melt-blend the above components in a twin-screw extruder at 125°C, and pelletize to obtain composite material particles.

[0061] Pad preparation and functionalization:

[0062] A suitable amount of composite material particles were placed in a mold and molded at 135℃ and 15MPa for 20 minutes. After cooling to 50℃, the mold was opened to obtain a blank of the molded pad. The blank of the molded pad was placed on the worktable of the digital light processing system, and a preset pattern digital mask file was loaded. A light energy density of 1250mJ / cm² with a center wavelength of 365nm was used. 2 The surface of the blank of the pad is selectively exposed to ultraviolet light to complete the functional writing, thus obtaining the new pad of Example 4.

[0063] Comparative Examples 1-4:

[0064] Comparative Example 1:

[0065] Compared with Example 4, the difference is that in the composite material preparation step, the spiropyran derivative (latent molecular-level thermosensitive dye) prepared in Example 1 is not added, and its 0.5% mass fraction is replaced by furan-functionalized dynamically crosslinked polyurethane prepolymer, while the rest are the same.

[0066] Comparative Example 2:

[0067] Compared with Example 4, the difference is that in the composite material preparation step, the 2-nitrobenzyl-protected coumarin derivative (latent photoluminescent molecule) prepared in Example 1 is not added, and its 0.5% mass fraction is replaced by furan-functionalized dynamically crosslinked polyurethane prepolymer, while the rest are the same.

[0068] Comparative Example 3:

[0069] Compared with Example 4, the difference is that in the composite material preparation step, 1,1'-(methylenedi-4,1-phenylene)bismaleimide (crosslinking agent) is not added, and its 7.0% mass fraction is replaced by furan-functionalized dynamically crosslinked polyurethane prepolymer, while the rest are the same.

[0070] Comparative Example 4:

[0071] Compared with Example 4, the difference is that the functional writing step of selectively irradiating the blank of the pad is omitted, while the rest are the same.

[0072] Test Examples 1-4:

[0073] Test Example 1:

[0074] The pads prepared in Examples 2-4 and Comparative Examples 1-4 were used as test samples. The test method is as follows: Each pad sample was placed on a programmable heating plate, and a heating program was set to heat it from an initial temperature of 25°C to a final temperature of 80°C at a constant heating rate of 5°C / min. During the heating process, the preset pattern area of ​​each pad sample after selective light irradiation was continuously observed visually, and the starting temperature at which a recognizable color change occurred in the preset pattern area was recorded using a temperature sensor integrated with the heating plate. If no color change was observed throughout the entire heating range, it was recorded as no change. The test results are recorded in Table 1.

[0075] Table 1. Test Results of Temperature-Sensitive Alarm Function

[0076]

[0077]

[0078] Test results showed that the pads prepared in Examples 2-4 all exhibited clear color changes in their preset pattern areas under heating conditions. This is because, during the functionalization writing step, selective illumination caused the CO bonds of the latent molecular-level thermosensitive dye (spiropyran derivative) to break, transforming it into an open-ring anthocyanin structure with a conjugated structure. This open-ring anthocyanin structure is unstable under heat, and its molecular configuration changes, leading to a change in its absorption spectrum of visible light, which macroscopically manifests as a color change.

[0079] The sample in Comparative Example 1 did not show any color change because its formulation did not contain a spiropyran derivative, lacking the structural basis for achieving thermosensitive color change. The sample in Comparative Example 4 also did not show any color change because, although it contained a spiropyran derivative, it did not undergo a selective light-induced functionalization process. Therefore, the dye molecule remained in the closed-ring spiropyran form, a structure that is insensitive to temperature and cannot change color upon heating.

[0080] The results of the above embodiments and comparative examples collectively demonstrate that by combining latent molecular-level thermosensitive dyes with a matrix material and incorporating a selective photoluminescence step, the thermosensitive warning function can be solidified within a predetermined area of ​​the material through a change in molecular structure. The resulting pattern markings become integrated with the substrate, exhibiting intrinsic functionality compared to surface printing or physical engraving. Even after friction, the thermosensitive function is retained as long as the material itself remains, thus confirming the effectiveness of this technical solution in improving the durability of markings.

[0081] Test Example 2:

[0082] The pads prepared in Examples 2-4 and Comparative Examples 1-4 were used as test samples. The test method is as follows: Each pad sample was placed in a dark room, and a handheld ultraviolet lamp with a center wavelength of 365 nm was used to irradiate the preset pattern area of ​​each sample after selective illumination treatment. While irradiating, visual observation was performed from a direction perpendicular to the sample surface to determine whether the preset pattern area emitted visible fluorescence. If fluorescence was observed, it was recorded as fluorescence; otherwise, it was recorded as no fluorescence. The test results are recorded in Table 2.

[0083] Table 2. Results of Photoluminescence Verification Functional Tests

[0084] Sample number Does the preset pattern area fluoresce? Example 2 Fluorescence Example 3 Fluorescence Example 4 Fluorescence Comparative Example 1 Fluorescence Comparative Example 2 No fluorescence occurred. Comparative Example 3 Fluorescence Comparative Example 4 No fluorescence occurred.

[0085] Test results show that the samples in Examples 2-4, Comparative Examples 1 and 3 all emitted visible fluorescence in their preset pattern areas under ultraviolet light irradiation. The mechanism of this phenomenon is that during the functionalization writing step of the pad preparation, ultraviolet light of a specific wavelength triggered a photochemical reaction inside the 2-nitrobenzyl-protected coumarin derivative. Specifically, the light energy caused the 2-nitrobenzyl photosensitive protecting group to break and detach from the coumarin ring.

[0086] After the protecting group is removed, a free 4-methylumbelliferone molecule with a conjugated large π-bond structure is generated in situ. This molecule, acting as a fluorophore, absorbs ultraviolet light energy of a specific wavelength and releases energy in the form of visible fluorescence, thus making the pre-designed pattern area identifiable under ultraviolet light. The formation of this fluorescent label is based on a permanent chemical transformation at the molecular structural level and is fixed within the polymer matrix.

[0087] The sample in Comparative Example 2 did not fluoresce because its composite material formulation lacked a 2-nitrobenzyl-protected coumarin derivative, thus lacking the material basis for generating a fluorescent signal. The sample in Comparative Example 4 also did not fluoresce because, although it contained latent photoluminescent molecules, it had not undergone selective illumination during the functionalization writing step, and the photosensitive protecting group was not removed, preventing the formation of a molecular structure with a fluorescent effect. This set of tests confirms that this technical solution constructs an embedded, verifiable anti-counterfeiting feature by selectively generating fluorescent substances in situ within the material.

[0088] Test Example 3:

[0089] To evaluate the durability of the functional markings prepared by this technical solution, the novel pad obtained in Example 4 was used as a test sample. A control sample was also prepared: a blank pad without functionalization was taken (prepared using the same method as the blank pad in Example 4), and a pattern identical to the light-written area in Example 4 was printed on its surface using conventional screen printing technology. After the ink dried and cured, it served as a control sample.

[0090] The test method is as follows: A reciprocating friction testing machine was used to test the wear resistance of the test samples and control samples. Test parameters were set as follows: the friction head used 00# steel wool, the applied load was 750g, the reciprocating stroke was 20mm, and the reciprocating speed was 40 times / minute. Samples were removed after 500 and 1000 cycles of friction testing. For the test samples, the integrity of their temperature-sensitive warning function and photoluminescence verification function was verified using the methods described in Test Examples 1 and 2. For the control samples, the wear of the printed patterns on their surface was visually observed. The percentage of the effective area of ​​the patterned region relative to the initial area was used as the functional integrity. The test results are recorded in Table 3.

[0091] Table 3. Results of Marking Abrasion Resistance Test

[0092]

[0093]

[0094] The test results above show that after 1000 cycles of reciprocating friction, the temperature-sensitive warning pattern and photosensitive verification pattern of the pad prepared in Example 4 still maintained a functional integrity of over 98%, with no significant attenuation of the functional areas. In contrast, the control sample prepared by surface screen printing showed severe wear after 500 cycles of friction, and the pattern was almost completely worn away after 1000 cycles of friction, with a functional integrity of less than 5%.

[0095] The results confirm that the functional markings formed by this technical solution possess high wear resistance. The mechanism lies in the fact that the functional markings are not attached to the two-dimensional surface of the pad, but rather formed by selectively irradiating specific three-dimensional regions of the pad matrix material, inducing in-situ chemical structural transformations of latent functional molecules. The resulting molecular structures, exhibiting temperature-sensitive and photoluminescent effects, are uniformly distributed within the polymer matrix of the irradiated area.

[0096] Therefore, the functional markings and the substrate are physically integrated. Mechanical friction on the surface only removes the outermost layer of the material, while the molecules beneath, which have also undergone chemical structural transformation, continue to perform their function. As long as the substrate material itself is not completely worn through, the embedded functional markings will remain and function continuously. This characteristic solves the technical problem of traditional surface-printed or engraved markings easily failing due to wear and scratches, ensuring the reliability and durability of temperature-sensitive warnings and photoluminescence verification functions during long-term use.

[0097] Test Example 4:

[0098] To evaluate the self-healing properties of the substrate material, composite materials prepared in Example 4 and Comparative Example 3 were selected for testing. The test method is as follows: Both composite materials were molded into standard dumbbell-shaped tensile specimens. Each specimen was completely cut at a narrow central section using a blade, forming two independent fractured parts. Subsequently, the two fractured parts of the same specimen were aligned along the cut surfaces and brought into close contact, and then heat-treated in an oven at 120°C for 2 hours. After heat treatment, the specimens were removed and cooled outdoors.

[0099] Tensile tests were performed on the repaired specimen and the undamaged original specimen using a universal testing machine, and the maximum tensile strength at fracture was recorded. The self-healing efficiency was calculated by the ratio of the tensile strength of the repaired specimen to that of the original specimen. The test results are recorded in Table 4.

[0100] Table 4. Self-healing performance test results

[0101] Sample number Original tensile strength (MPa) Tensile strength after repair (MPa) Self-repair efficiency (%) Example 4 13.1 11.6 88.5 Comparative Example 3 8.8 0.4 4.5

[0102] Test results show that after being cut and repaired by heat treatment, the tensile strength of the sample in Example 4 recovered to 88.5% of its original strength. In contrast, the tensile strength of the sample in Comparative Example 3, under the same treatment conditions, only recovered to 4.5% of its original strength, indicating that it has virtually no repair capability.

[0103] This self-healing property originates from a dynamic covalent network built within the material matrix. This network is based on a reversible Diels-Alder reaction between furan groups in the furan-functionalized polyurethane prepolymer and maleimide groups in 1,1'-(methylenedi-4,1-phenylene)bismaleimide. When the material is damaged (e.g., cut), the covalent bonds on the damaged surface are mechanically broken. At a set thermal repair temperature, the formed Diels-Alder adduct undergoes a reverse reaction, partially breaking down into furan and maleimide groups, while simultaneously increasing the mobility of the polymer segments.

[0104] When the damaged interface re-contacts, the furan groups and maleimide groups on both sides of the interface diffuse with each other due to chain segment movement and undergo a positive Diels-Alder reaction again, forming covalent bonds at the interface once more. This heals the macroscopic crack and restores the mechanical integrity of the material. Comparative Example 3, because its formulation does not contain a bismaleimide crosslinking agent, cannot form this reversible dynamic covalent network. Therefore, it cannot rebuild chemical bonds through heat treatment after fracture, and its self-healing effect is not significant. This test confirms that this technical solution, by introducing a specific dynamic chemical system, enables the pad material to possess the ability to autonomously repair physical damage, thus extending its service life.

Claims

1. A novel shim characterized by, The backing plate is made of a composite elastomer material, the composition of which is as follows in terms of mass percentage: Dynamic crosslinking self-healing elastomer matrix: 85.0%-95.0%; Crosslinking agent: 4.0%-10.0%; Latent molecular-level temperature-sensitive dye: 0.1%-1.0%; Latent photoluminescent molecule: 0.1%-1.0%.

2. A novel pad according to claim 1, characterized in that, The dynamic crosslinking self-healing elastomer matrix is a furan-functionalized dynamic crosslinking polyurethane prepolymer.

3. A novel pad according to claim 1, characterized in that, The crosslinking agent is 1,1'-(methylene di-4,1-phenylene) bismaleimide.

4. A novel pad according to claim 1, characterized in that, The latent molecular-level temperature-sensitive dye is a spiropyran derivative.

5. A novel pad according to claim 1, characterized in that, The latent photoluminescent molecule is a 2-nitrobenzyl-protected coumarin derivative.

6. A process for the manufacture of the new mat according to any one of the preceding claims 1-5, characterized in that, The method comprises the steps of: S1, melt blending the dynamic crosslinking self-healing elastomer matrix, the crosslinking agent, the latent molecular-level temperature-sensitive dye and the latent photoluminescent molecule to obtain a homogeneous composite material; S2, molding the composite material at a temperature of 120-150℃ and a pressure of 10-20MPa to prepare a backing blank with the overall function in a latent state; S3, using a light source with a central wavelength of 360-375nm to selectively irradiate the preset pattern area on the surface of the backing blank, synchronously activating the latent molecular-level temperature-sensitive dye and the latent photoluminescent molecule in the area, while the two molecules in the non-pre-set pattern area remain in a latent state, and finally obtaining a new type of backing plate.

7. The process for machining of a novel pad plate as claimed in claim 6, wherein, The melt blending in step S1 is carried out at a temperature of 110-140℃.

8. The process for machining of a novel pad plate as claimed in claim 6, wherein, The molding in step S2 is carried out at a temperature of 120-150℃ and a pressure of 10-20MPa, and the holding time is 15-30 minutes.

9. The process for machining of a novel pad plate as claimed in claim 6, wherein, The central wavelength of the step S3 is 360-375 nm, and the light energy density is 500-2000 mJ / cm 2 .

10. The process for machining of a novel pad plate as claimed in claim 6, wherein, The selective irradiation in step S3 is specifically as follows: using a digital light processing system, a digital mask file containing the preset pattern is used to spatially modulate the light beam emitted by the light source through the digital micromirror device built in the system, forming a light field that accurately corresponds to the preset pattern, and projecting the light field onto the surface of the backing blank.

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