FI118163B - Apparatus for detecting changes in temperature, method for making the apparatus and the use thereof - Google Patents

Description

118163

Apparatus for detecting temperature changes, a method for making the apparatus, and "1

using the device I

The present invention relates to a device according to the preamble of claim 1 for temperature X

5 to indicate changes. Such a device comprises nanoscale particles consisting of structures with high light scattering ability and high opacity which, as a result of temperature change, are capable of collapsing to form larger structures having substantially reduced light scattering ability and opacity. -

• -.'- S

The invention also relates to a method according to the preamble of claim 11 for the manufacture of a device for detecting temperature changes and the use of the present devices as or in combination with a temperature or heating foam for detecting exceeding a predetermined limit temperature.

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Recently, attempts have been made to find low-cost temperature monitoring devices, especially for the food industry. The utilization of the properties of nano or almost > .and nanoscale fibers, droplet particles, and combinations thereof provides a solution to this situation. > · *. *. f

- *. * The diameter or smallest dimensions of these particles are a few micrometres or

Φ · *., ·! * ·:. * Better. At present, there are commercialized disposable * * ·

* * · TM

“Working sensors, the most famous of which is MonitorMark, manufactured by 3M, Lifelines

FreshCheck ™ and Cox Technologies' Vitsab®. However, the above mentioned products have their own weaknesses:, • · · 5 "• * · • · ·: 4

,, Function of MonitorMark 1M based on diffusion, FreshCheck 1M polymerization reaction \

• · · * * * «S ''. * *. * And enzymatic hydrolysis of Vitsab lipids. The above reactions are slow, which causes the sensors to respond slowly to external stimuli and not thus, temperature- * * * * * * · "30 gauges are not reliable. f ··· * · * · *« · ·. ·. · The fabrication and color change of nano- or near-nano-scale fibers are described * * * * ... · Pedicini, A. et al., Thermally Induced Color Change in Electrospun Fiber Mats,

Polymeric Materials: Science and Engineering, 87, 373 (2002). ··· Ό 2: Λ:; f.

Ψ 1181631 is based on carbon black-doped polymeric (PC, PEO and PMMA) fibers τ ', which are white or off-white under their glass transition temperature and melting point, but when formed in the melt state, form larger units of carbonaceous structure.

5

Various structures and manufacturing methods made of nanofibres or blends of fibers are disclosed, e.g. U.S. Patent No. 6,110,590. WO 2004/016839 discloses an apparatus for the preparation of nanofibers by electrostatic fiberization and a nozzle construction used in the process.

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There is no disclosure in the prior art of kiosk or publications of a method for nano- or near-nano-scale fibers, droplet-like particles or their compounds.

- '' Λ'ι 'for the use of temperature-controlled structures. The manufacture of nanoscale 15 fibers for temperature monitoring and observation is also not discussed · • '31

The object of the present invention is to eliminate at least some of the problems of the prior art. In particular, it is an object of the invention to provide temperature detectors, i.e., a temperature monitor-20, capable of detecting even small changes in temperature.

* · • · · • ♦ 9 • ·

. · 1. A

The present invention is based on the idea that a 1 · 1 · * · ”temperature monitoring device employs nanoscale particles of polymers or alloys of polymers which are superimposed on a substrate to form a base layer. 25 at temperature covers at least a portion of the substrate surface and prevents the observer from seeing • · '··· 1 of this substrate surface.

• · '-i • 1 h • · · "1.1 The solution is based on the phenomenon that nanoscale or near-nanoscale particles, or combinations of small molecules * 1 * · *** • 30 · of the distillates, polymers or mixtures thereof (including those doped with fillers) are white, off-white or off-white and have a high opacity,

• · 'S

Due to the high light scattering properties of the structures. However, as a result of a temperature change, i.e., a rise in temperature of 1 ° C, the nanoparticle particles lose at least about 118163 3 * parts of their light scattering capacity and hence their opacity, whereby the substrate is visible through a layer of nanoscale particles.

Based on the foregoing, the invention relates to a device for temperature monitoring comprising a surface of " substrate material " and 4 - a surface of nano-scale or near-nano-scale fibers, droplets or combinations thereof having fibers, particles or combinations thereof form a fracture field capable of collapsing when the device is brought to a temperature above the melting point of the particles, the glass transition temperature, or both.

1 '·' £

The device according to the invention is used e.g. in the nanoscale structures formed by y. If the surface of the substrate material readily ...: has a distinctive specific color or has a pattern or other marking, the change in temperature 20 is readily detectable when the surface-coating layer loses its opacity, whereby the specific color of the substrate material is · · · ***** • · * ***! treated therein.

• · · • · · * * ····

. . More specifically, the device of the present invention is characterized by J

* · · • · · - lt “1/25 as set forth in the characterizing part of claim 1. · ♦ · • · ···; The process according to the invention, in turn, is characterized by what is stated in claim 11, and in the uses according to the invention that is disclosed in claims 13, 18 and 19.

• · t «* · •: 3o • · * · · * *. <,. The invention provides clear advantages over the prior art. Various types of processing- 4 '• ·? By employing process methods, such as electrostatic fiberization, simple starting materials such as conventional commercial polymers or mixtures thereof, and mixtures with fillers are also possible, produces a temperature of 118163; | 4. Equivalent and durable but responsive devices for monitoring, the manufacture and use of which are inexpensive.

* • 's

The color change 5 of temperature sensors made of nanoscale fibers and particles is based on structural changes due to changes in temperature of the structures formed by the fibers or particles or combinations thereof, the starting temperature, 4, i.e. the boundary temperature being monitored, can be adjusted very precisely. 3

The devices according to the invention can be used as temperature switches, in electronic component 10 and for the production of thermographic paper.

'45

Other details and advantages of the invention will be apparent from the following detailed description! s. t λ -a 15 Figures la-Id show a series of four photographs showing the color change of a polyethylene oxide temperature transducer when the limit temperature is exceeded.

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Figures 2a and 2b show the principles of changes in glass transition temperatures of polymer blends based on the relative volume fractions of the polymer components. Fig. 2a shows the situation for homogeneous polymer cokes and Fig. 2b shows the situation respectively; • »for rogenic polymer blends.

• · · • · * * * * * * * i ,. ^:, * ·· Figures 3a and 3b show TEM images of the binary continuous structure of the '· *' · nanofiber formed from the PS-P4VP (PDP) io complex, Fig. 3a is taken in the direction of the fiber * ·: 25 and Fig. 3b respectively against fiber.

• * ·> # *

As indicated above, the device for detecting temperature changes in the invention comprises nanoscale components consisting of structures with high light scattering and high opacity which, as a result of the change in temperature, are capable of:. · * 30 are able to form larger structures with substantially reduced light ··· cavity and opacity. These particles include, for example, very small (i.e., '' nanoscale * '-il · *' * '') fibers, particles, and combinations thereof. Nanoscale generally means,? • · · *: **; that the smallest dimension of the fibers or particles or similar structures or combinations thereof is less than about 1 micrometer on average, preferably e.g., the diameters of the fibers are-5 118163-about 10 to 500 nm. Generally, the particle sizes are smaller than the wavelengths of visible light.

The term "particles" refers to small fibers and fibrils, particles (including spherical and droplet-like particles) and structural units of indeterminate shape, consisting of molecular compounds, polymers, or mixtures thereof, the latter of which may optionally contain fillers. 1

Parts, especially fibers and fibrils, may be prepared, for example, by electrostatic defibration, as disclosed in our earlier FI patent application 20040493, the contents of which are incorporated herein by reference. Electrostatic defibration is a processing method in which the consumption of the material to be defibrated is usually 0.1 to 0.001 g / m2 depending on the thickness of the fiber layer.

In accordance with this technique, the temperature monitoring device of the present invention is prepared from at least one polymer by a method of: - providing a fiberizing solution or melt containing at least one polymer or polymer blend having a viscosity greater than 0.0001 N / ms, preferably greater than 0.1 N / ms. , and - the polymer or polymer blend Accelerated by electrostatic comforter such that the fiberizing solution or melt is fed through a capillary pipeline reserved for the first potential into a second potential receiving region.

The typical potential difference and the distance between the above electrodes is preferably 0.1 to 10 kV / cm, especially about 0.5 to 5 kV / cm, and respectively 10 - 1000 mm, especially about 50 «• * 1 .. 1 1: ··: 25 500 500 mm. The simple, electrostatic defibration described above is a very inexpensive means of providing a suitable device for monitoring the temperature. It should be emphasized that the present; However, the process for producing the invention is not limited to electrostatic fiberization, but only to nanoparticulate or near-nanoscale fibers, droplet-like particles or their ························································································• · *% Other well-known manufacturing techniques can be used as the manufacturing method for the combination • -> Λ ··· ί.

·· ♦ ··· «· • ·; ;

118163 I

6 ί

Fibers and particles can be made of polymers, particularly thermoplastic materials such as polyethylene oxide (PEO), polycarbonate (PC), polystyrene (PS), and acrylate and methacrylate polymers such as polymethyl methacrylate (PMMA). The polymer is selected so that the nanofibre fiber or particle produced therefrom has a glass transition temperature and / or a melting point (s) which are (are) proportional to the desired cut-off temperature. In this case, the boundary temperature refers to the temperature above which it is desired to indicate. Changes in the structure of nanoscale particles can, depending on the material, occur either before the temperature reaches the glass transition point j and / or the melting point or just above this / these. Thus, for example, the change in the structure of the polyethylene oxide fibers begins at the melting point (59.5 ° C) of the powdered PEO, as shown in the accompanying drawings 1a-Id. The change in the structure of the polymethyl methacrylate fibers / particles occurs only well above the glass transition temperature. f The conversion temperature of PC fibers is approximately 135 ° C and that of PMMA fibers is approximately 160 ° C.

Mixtures of polymers can also be used in the invention, whereby the polymers have different glass transition temperatures / melting points. This application is discussed in more detail below. In addition, the temperature at which structural changes begin can be influenced by the use of alloying materials.

Materials made from polymer blends combine different properties of polymer components. For example, homogeneous (and also heterogeneous) polymer blends can achieve mechanical properties better than those of the blending polymer components. More important for the invention is the property of homogeneous polymer blends. *: Adjust the glass transition temperature (Tg). With homogeneous polymer blends which: ··· * · * * typically consist of chemically similar polymers (A, B), it is observed • · * * *

Li: 25 only one glass transition temperature obtained from the volume scaled mean (0a, 0b) of the glass transition temperatures (T £ a, T £ b) of the mixed polymers. In other words, the glass transition temperature of homogeneous polymer blends can be "infinitely controlled" between the glass transition temperatures of the polymer blend polymer components by changing the relative volume percentages of the polymer components (Strobl, G., in Phys. of Polymers, Springer, Berlin 1997, pp. 83-128) (see Figure · * ♦ 2a).

··· • · • · · • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 7 7 7 7 7 7 ·

The heterogeneous polymer blend, in turn, exhibits two glass transition temperatures which are: f identical to those of the polymer components, i.e., the magnification of the glass transition increases with the volume fraction of the polymer component (see Figure 2b).

5 In the case of polymers, eutectic phase behavior similar to, for example, water and alcohol occurs under normal atmospheric pressure. the melting point is lower than that of the starting materials. The melting point of polymer-solvent systems can thus also be controlled by adjusting the volume fractions of the polymer and solvent. For example (in the case of a mixture of polyethylene oxide and resorcinol, a phase diagram of 10 so-called eutectic points is observed, the mole fraction of resorcinol has a melting point of 43 ° C and a mole fraction of 0.49 having a melting point of 86 ° C.

The glass transition temperature and melting point of the block copolymers, graft copolymers, and random block copolymers may be adjusted by the choice of polymer blocks, chemical modification, or by adjusting the mutual volume fractions or molecular fractions of the polymer blocks such as Papageorgiou G. Z. have shown in Polymer Intemational, in their article Melting point depression and cocrystallization behavior of poly (ethylene-co-butylene 2,6-naphthalate) copolymers (Polym. Int., 2000, 53, 1360-1367), the contents of which are incorporated herein by reference. An example is polyethylene-2,6-! . . Block copolymers of naphthalene (PEN; Tg 122 ° C, Tm 268 ° C) and polybutylene-2,6-naphthalene (PBN; Tg 71 ° C, * Tm 242 ° C). Volume fractions or, in this case, molar fractions of blocks • *! By systematically adjusting it, the glass transition temperature (Tg) * * * and the melting point (Tm) of the block polymers (EB) can be systematically adjusted (see Table 1).

* * • * * * * • * 4 • * * * * * * • · * 4 ...> * · · • • • * * * * 'i • · · ·, / ¾ t 9 I. 't * · * * * * * • • • • • • * * * *? * ♦ · • • * 9 * • 4 • · 4 * 4'

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'% • i, / 118163 4 8' t

Table 1 Sample- R a r a c t i o n s> Code (dig-1) rg (* q rm (° q PEN 0.46 122 268 EB1 0.60 118 253; EB2 0.53; 113 243 'EB3 0.56 107 222 EB4 0.60 100 220 :, - EB5 0.58 92 195 EB6 0.50 80 208 cB7 0.70 77 230 EB8 0.60 72 240 P8N 0.61 71 242 1

In the case of polymer blends, the proportions of the polymer components may vary freely,? 5 provided that the desired properties of a glass transition temperature or a corresponding for the lamina. Generally, for two polymers, the molar ratio of the A and B components is in the range of 0.1: 99.9 to 99.9: 0.1, typically about 10:90 to 90:10.

As noted above, most of the thermoplastic polymers obtained by the above process 10 have nano-scale or near-nano-scale particles which are white, off-white or off-white and have high opacity due to the high light scattering properties of the above mentioned structures. When nano-scale or t • -:> near-nano-scale components such as those mentioned above, surfaces are processed on surfaces of different colored substrates -> Φ Λ • »t *. *. * le, the reflection of the characteristic color of the substrates is completely or almost completely prevented.

*> 15 • * * · · • • ί: Shapes of larger structures formed as a result of temperature change * · * ··· * * vary between thin film, mesh or droplet shape according to surface energies. Whatever the shape of the collapsed structures, their light scattering power and • opacity have been substantially reduced as a result of the collapse, allowing the characteristic color of the substrate or the pattern on the surface to be reflected and exposed.

• · * · »• · Φ

Since temperature change causes the structures to collapse, even a momentary excess of the *. ·. * Temperature is sufficient to cause the substrate to be color-rendered or to render the surface l * · · '...' irreversible. Thus, the temperature monitor according to the invention is disposable 's 118163 9.}, And even structural changes due to transient temperature increases cannot be retrospectively altered, i.e. the results of the temperature change cannot be "tampered with".

The phenomenon shown can be utilized in temperature monitoring and observation. Thus, the term 'lamp-state monitor' used in connection with the Kek-5 invention refers to a device suitable for monitoring temperature.

: t

In a preferred embodiment of the invention, the nanoscale particles form a continuous layer on the surface of the backing layer that covers a selected portion of the surface of the backing material.

In the temperature monitor, at least 5%, preferably at least 10%, particularly preferably about 15- ..

100% of the surface of the substrate is covered with such a layer, this portion of the substrate forming said temperature monitor. It is expedient that such a large portion of the substrate surface is covered such that the covered surface becomes visually perceptible.

at least some distance, when the covering layer becomes transparent or translucent as a result of temperature rise.

EK

The thickness of the layer will always vary according to the nanoscale particles and the color or pattern of the substrate to be coated, but will generally be from about 0.5 to about 1000 micrometers, particularly from about 1 to about 500 micrometers, preferably from about 10 to about 100 micrometers.

20 • * · γ *. * The base material of the temperature monitor according to the present invention may be any of * * · * · · **. any suitable, preferably at least substantially planar, substrate, such as paper, cardboard. ton, metal film, glass, polymer film, or metal or polymer sheet or a combination of these. . such as plastic coated paper, cardboard, glass or metal sheet. The substrate »· *) ·· / 25 can be self-supporting with a basis weight of * 80 * 500 g / m 2 for paper and board. However, the base material is not limited to the plane *. but the temperature indicator function according to the invention can be • · *. * · *. can also be achieved by depositing a sufficiently thick layer on an uneven surface as described above. working parts.

• * * •: 3o «« ·· * • ·

The base material may have a uniform color throughout, also referred to above as the native color, or may be patterned by continuous or discrete patterning at least over the area covered by the · · * · **. Color signals or written or patterned messages can be formed under the overlay. Λ 118163 ίο

The substrate may also be translucent or translucent, allowing the temperature monitor to be combined with a light source + sensor combination, e.g., a low-energy (e.g., IR) source + sensor, one imaged behind the substrate and the other in front of the covering layer 5. In this case, the collapse of the covering layer can be observed as an increase in transmission.

The color or pattern of the base material may also be varied at different points in the material and, if desired, two or more temperature monitors may be used on the same substrate, preferably consisting of different polymer blends having structural changes at different temperatures. Thus, a temperature monitoring device is provided which can detect a temperature at a specific interval. When the temperature, even momentarily, exceeds the boundary temperature of the lower temperature variable polymer blend, a certain substrate color or pattern is revealed under this blend, but since the other temperature guard has not yet exceeded the boundary temperature, the substrate color or pattern has not yet become apparent. that the temperature has been at least momentarily in the interval between the limiting temperatures of said temperature monitors.

In the basic solution, the color change of the temperature monitor is based on the structural and consequent physical changes caused by the temperature changes, for which the onset state and the monitored limit temperature can be accurately controlled. The temperature limit is in this respect asetel- Γ * * * '·' tavissa about half a degree of the polymer material by, as shown below presented below * · ·

• · A

** ·, only the example and the pictures below show.

* * * * · »* · • ·. . According to another preferred embodiment, the color change of the temperature monitors is based on UV • · ♦ * “, * 25 activation, whereby the irradiation with UV light causes partial fragility of the fiber structure. For this embodiment, the polyacrylate used in the electronics industry, such as polymethyl methacrylate (PMMA) or other UV-degradable polymers, is preferably added to the polymer solution working by electrostatic fiber, and optionally. also a UV activator. Thus, the fiberizable polymer blend is prepared • · * «» *; 30 of at least two polymers. At the right volume ratios, preferably 0.1: 0.9-0.9: 0.1, if- * ···· • «. UV-degradable polymer, such as polyacrylate, in the fiber, and another polymer! The * * · * · * · * component forms a double continuous structure similar to Figure 3. At higher temperatures, the melting polymer phase forms a support structure. The structure of the biphasic fiber will not collapse until this higher melting polymer has reached its melting point of '4¾ 118163' π or its glass transition temperature (e.g. ΡΜΜΑ: η is about 150-170 ° C) even if one of the fiber polymer components is already in the melt state. The temperature monitor of the fibrous material is activated by irradiating the fiber with UV light, whereby the higher molecular weight of the meltable polymer, preferably the polyacrylate (or polyacrylates) is reduced and can no longer function as a support structure for the fiber. The above treatment after that, the structure of the fiber collapses at a lower temperature when melting polymer melt or glass transition temperature. The lower melting polymer thus acts as a thermal cracker after the higher melting polymer has been degraded if not by UV light, f io.

The structure of the above-mentioned second embodiment does not collapse even if the second polymer phase is removed or degraded if the remaining phase is not in the molten state. This type of temperature monitor thus facilitates the handling of especially low temperature temperature monitors prior to incorporation into the product being monitored.

15 •. 1-1¾ By properly selecting the melting point, glass transition temperature, or a combination of both, the polymer or polymer blend, the method or apparatus of the present invention can be used for a variety of applications.

The temperature monitors of the present invention are suitable, for example, for controlling the temperatures of food packaging, pharmaceuticals and many other heat-sensitive products. to the quay mm. at different stages of the cold chain. In addition, temperature ranges can be used to monitor the high temperatures of food items, such as the degree of maturity of ready or half meals. Thermal • ·. space monitors can also be utilized in the electronics industry, for example, by finding • ♦ · I ". Faults due to overheating of components with 25 temperature monitors • · and easy through color change of the thermocouple. Thermal space monitors can also be combined: with RFID technology; · · ··· *. ···. It is easy to see if the sensor combination has a * * · temperature of the product being monitored that is above its maximum set temperature.

* * · • · · *: 30. '* ·· * »• ·

According to a first preferred practical embodiment, the method according to the invention • · ·

is used to produce temperature sensors suitable for temperature monitoring, which allows A

• · * *** lists a new, inexpensive and effective solution for controlling the cold chain, among others. individual packaging 118163; 12: Compliance with temperature regulations for supported foods and pharmaceuticals, or to detect improper handling of packaged products in the cold chain.

For example, when placing a temperature monitor in a consumer-wrapped meat package such that heating of the product-specific package and also the temperature monitor correlates with heating the contents of the package and selecting the polymer or polymer melt temperature, glass transition temperature, or both. the temperature reaches that cut-off temperature when the contents of the package have reached Ί or above the critical cut-off temperature set individually for the product;

10 watches to use eg. monitoring food temperature limits for cold chains J

in different phases.

According to another preferred practical application, the temperature monitoring devices of the invention monitor the heating and cooking of ready-to-cook foods and raw and semi-finished products prepared in an oven and microwave oven. Temperature monitors suitable for the above task are referred to herein as the "" heating monitor ". The discoloration in the heating watch indicates that the meals are sufficiently warm and mature to be eaten, which facilitates the detection of the required degree of maturity or warming, while reducing the amount of meals spoilage due to overheating.

• x • * x *

When placing the heater in a heated package so that the heating of the package shell · · correlates with the heating of the product in the package and by selecting ί • '· · "* * polymer or polymer alloy melting point, glass transition temperature or both so that The temperature of the product-specific packaging, and thus the heating watch, reaches that limit when the contents of the package have reached the desired product-specific temperature, the invention is well suited for monitoring the heating and cooking of ready-to-eat foods and ♦ · preparations.

According to a third preferred practical application, temperature monitors are utilized in the electronics industry, for example, in freezing a defective component by overheating, by connecting or enclosing an electronic component in a temperature monitor. Elekt - * "*! Ronic components are usually damaged at high temperatures, whereby the thermal space watch also needs to be tailored to its high cut-off temperature.

13 I

118163

high melting polymers such as polystyrene

reen, polycarbonate, polymethacrylates, polyolefins.

According to a fourth preferred practical embodiment, the temperature monitors are combined with RFID-5 technology, whereby, for example, the temperature monitor may serve as a memory for the RFID sensor. By monitoring the refractive index, scattering, or opacity of the surface of the temperature monitor, the RF1D sensor is able to detect whether the sensor combination has at any point been above the set maximum temperature. The combination of the temperature monitor and 1 RFID can also be designed to activate and send an alert / alarm when the light refractive index, scattering or opacity of the temperature monitor surface changes.

According to a fifth preferred practical embodiment, the process of the present invention is used in the manufacture of thermographic paper. Thermographic paper is commonly used in receipts, flags, stickers, etc. The advantages of this application to the methods previously used are the UV-light resistance, i.e., the printing of the paper does not lighten over time, which is a problem with commonly used thermographic papers.

In a sixth preferred embodiment, temperature monitors are used in which the polymer or polymer blend of i20 is selected so that its melting point or glass transition point is near room temperature, for example in domestic heating equipment: * mmm * · '· ", such as hair dryers, provides the ability to impregnate the polymer or polymer blend and thus reveal the color or pattern of the substrate. For example, this application can be used to make Christmas calendars that can be opened with • mm **; / 25 using, among other things, a hairdryer to display a picture or • · * ·· ** text under the door. »1 '' ',. ,, * · ·. '* · * ... The following non-limiting example illustrates the invention. ; • · • ·

· «· I

m • · .. · »5»: 30 Example 1 i ··· • · • «« ·· · ««

The temperature monitor made of polyethylene oxide was tailored to 59 ° C. The operation of this temperature monitor when the limit temperature is exceeded is shown in Figs. f \\ 118163 - 14;

Said temperature monitor was made of polyethylene oxide (Aldrich) having a molecular weight of 100,000 g / mol. A 15 wt% aqueous solution of polyethylene oxide was electrostatic defibrated onto a red-colored metal-coated sticker-based target at zero potential. The polymer solution was fed through a 1.8 mm internal diameter 5 mm capillary tube with a 51 mm length and 15 kV potential.

The distance between the capillary tip and the object perpendicular to it was 15 cm, with an electric field intensity of 1 kV / cm.

The operation of the device according to the invention is illustrated in the accompanying figures: 10

Figure 1 shows a high temperature (critical temperature 59 ° C) technology prototype heated by a Linkam TP 93 heater. In Fig. 1a, warming up took place

the temperature is stabilized to 58 ° C. In Figures Ib, Le and Id the temperature is increased by 2 ° C

s per minute and heating has lasted 15 s, 30 s and 45 s, whereby the temperature reached by the prototype in the situations shown in these figures -15 has been 58.5 ° C, 59 ° C and 59.5 ° C, respectively. · .'t.

A series of arrows have been added to the images in the series to make it easier to detect the heating guard.

Figure 3 shows two TEM images of the biphasic structure of the 'nanofiber' formed from the PS-P4VP (PDP) i-complex in the direction of the fiber (Figure 3a) and perpendicular to the fiber (Figure 3b). The diameter of the nanofibre in Figure 3b is about 150 nm when it is * · · ·: * • ®. part 3a has about 250 nm. 7 '-ä • * • · · • »· • · * • · · * • a • ·.

· · · · · · · · · · · · · ·

· - A

• · · * · p • · • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

* · «• · * · • * · * * * ···· '• ·;> • ·> • £ £ • · • • · / • 1 • · • • • • ·

Claims (19)

118163 An apparatus for detecting temperature changes, comprising: - nanoscale components consisting of structures of high light scattering and high opacity which, as a result of temperature change, are capable of collapsing and fusing particles together to form larger structures with substantially reduced opacity, , that - the nanoscale particles are imaged on the substrate layer so that they at least partially optically cover this material and prevent the substrate layer surface from being detected and, when collapsed, allow the substrate layer surface to be detected. f Device according to Claim 1, characterized in that the nanoscale particles form a uniform layer covering at least 5%, preferably at least 10%, particularly preferably about 15-100%, of the surface of the base material. £ Device according to claim 1 or 2, characterized in that the nanoscale particles consist of at least one type of small molecule or polymer or more. 20 polymer blend. * · * * · * · **; • * * • · *. *. Device according to one of Claims 1 to 3, characterized in that the nanoscale. *: ....: particles are composed of at least two polymers, the first of which forms particles 3 * · •. *. support structure and melts at a higher temperature than the other, and optionally UV-ii * · * '-34 ·: 1. 25 activations that together form a biphasic structure. ^ • · * *; Device according to claim 4, characterized in that the first polymer is: «...; 1; UV-degradable polymer such as polymethyl methacrylate. * * * * • ··> • · ···· * • * * • * * Device according to one of Claims 1 to 5, characterized in that the duplexer is continuous. the structure of the fiber will not collapse until the higher melting polymer has reached its melting point or glass transition temperature, even if one of the polymer components of the fiber is already in the melt state. 16:. 118163 Device according to one of claims 1 to 5, characterized in that the temperature monitor made of at least two polymers can be activated by irradiating the fiber with UV light, whereby the higher melting polymer loses its molecular weight and can no longer function as a support structure of the fiber. 5 at the melting point of the melting polymer or at the glass transition temperature. A device according to any one of the preceding claims, characterized in that the substrate material has a specific color or a recognizable pattern formed thereon, and the surface is in this respect covered with a layer of nano-scale particles of white, almost silent; 10, or an off-white color that prevents the overall color or pattern of the substrate from being completely or nearly completely reflected, resulting in the coated substrate reflecting outwardly or almost exclusively the characteristic color of the nanoscale particles. . . , Apparatus according to any one of the preceding claims, characterized in that it comprises nanofibres or particles made by at least one polymeric process, wherein: a - J - a fiberization comprising at least one polymer or polymer blend is prepared. -% solution or melt having a viscosity of greater than 0.0001 N / m 2 s, preferably greater than 0.01 to 20 N 7 M's, and * 1 · '; - converting the polymer or polymer blend into a fibrous form by electrostatic * · 1 • · · 1 defibration such that the fiberizing solution or melt is fed through a first potential capillary tube into a second potential receiving area. , the potential difference and the distance between the aforementioned electrodes * 1 1 '·! 25 being 0.5-10 kV / cm and 10-1000 mm respectively. A device according to any one of the preceding claims, characterized in that the. 2 3 4 5 ·. the melting point, the glass transition temperature, or both of the material or mixture of materials, ··· .1, selected such that the matrix of the fibrous, teardrop or combination of materials is · ·. The structure of the I 30 rial collapses from heating. 4 • · '«· 2 • · · 3 *;] · 1 11. A method of making a device for detecting temperature changes, characterized in that 118163 17, ¾ •. . - forming a layer on the surface of the substrate layer comprising nanoscale particles consisting of structures with high light scattering and high opacity which, as a result of temperature change, are capable of collapsing to form larger structures having substantially reduced lons scattering ability and opacity; wherein the nanoscale particles are arranged on the substrate layer such that they at least partially optically cover this material and prevent the substrate layer from being detected and, when collapsed, allow the material to be detected. * Method according to claim 12, characterized in that I - the surface of the substrate is provided with a specific color or a recognizable pattern is formed on the surface, and - the surface is covered in color or pattern with a layer of nanoscale particles of white, near white or off-white a color that prevents base material Use of a device according to any one of claims 1 to 10 for use in a temperature or heating cav . 20 tin. v • * · '. ··.? • · · • * · # · '• t · _. ' Use according to Claim 13, characterized in that the device is used in or in connection with the packaging, indicating that a predetermined limit temperature is exceeded in the packaging. Sessa. • * · • · · •• ♦ 25 • ·: · * • · ·: § • ♦ · V, Use according to claim 13, characterized in that the temperature monitor controls | The processing of packaged products in the cold chain. ** # · * · • · • * * /. Use according to Claim 13, characterized in that the device is used for monitoring the heating and cooking of ready-to-cook meals and raw and semi-finished products prepared in an oven or · microwave oven. . ..? • # · Ή • * φ Use according to claim 13, characterized in that the device is used in the electronics industry to monitor the temperature of the components. 118163 -.iti 15 The reflection of the specific color or pattern of the lithium is almost or entirely absent, with the coated substrate reflecting outwardly only or almost exclusively the color characteristic of nano-scale particles. Use of a device according to any one of claims 1 to 10 as an RFID sensor memory. "1 Use of a device according to any one of claims 1 to 10 for producing thermographic paper 5. •; · £ [i • · • »1 I 1 · • · · '• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • ••••••• #. "; • • • • • • • • ••••••••••••••••••••••••••••••••••••••••••• · · • · 1 • · • • • • • • • # 1 ·: 19. ’I 118163 Patentkrav’ ’-t