Method for estimating viscosity curve of polymer material

Abstract

The invention relates to a method for estimating the viscosity curve of a polymer material. The method comprises the following steps: acquiring the viscosity values of the polymer material at different temperatures (T) at different heating rates (beta); determining at least one viscosity profile of the polymeric material from the viscosities measured for each heating rate (beta); for each determined viscosity curve, splitting the viscosity curve into at least one determined melting curve and at least one determined curing curve; for each determined melting curve, determining at least one fitted melting curve; for each determined curing curve, determining at least one fitted curing curve; and estimating a viscosity curve of the polymeric material by combining the fitted melt curve and the fitted cure curve.

Description

Technical Field

[0001] The present invention relates to a method for estimating the viscosity curve of a polymer material. Background of the Invention

[0003] Typically, polymer materials may include one or more polymers, or a mixture of one or more polymers and one or more fillers. Polymer materials, such as prepregs, solder masks, glues, ABFs, etc., are important base materials for electronic devices and / or electronic device components (e.g., PCBs, ECPs and / or substrates). In addition, polymer materials are widely used in coatings as paints, for cloth fabrics, etc. Understanding the viscosity behavior of these materials allows the production of high-quality and / or low-priced electronic devices. Therefore, the viscosity dynamics of polymer materials are studied at the material identification stage, for example, in order to check whether a production process or steps of a production process are suitable for processing the corresponding polymer material. For example, the viscosity that a given polymer material may have after a certain duration and / or at a given temperature can be checked in advance.

[0004] However, there is currently no method to estimate the viscosity of an epoxy resin throughout its cure process. Summary of the invention

[0005] It is an object of the present invention to overcome at least some of the above problems.

[0006] This object is achieved by the subject-matter of the independent claims. Further exemplary embodiments are evident from the dependent claims and the following description.

[0007] One aspect of the present invention relates to a method for estimating a viscosity curve of a polymer material, the method comprising: obtaining viscosity values ​​of the polymer material at different temperatures under different heating rates; determining at least one viscosity curve of the polymer material based on the viscosity measured for each heating rate; for each determined viscosity curve, splitting the determined viscosity curve into at least one determined melting curve and at least one determined solidification curve; for each determined melting curve, determining at least one fitted melting curve; for each determined solidification curve, determining at least one fitted solidification curve; and estimating the viscosity curve of the polymer material by combining the fitted melting curve and the fitted solidification curve.

[0008] The polymer material may include one or more polymers, or a mixture of one or more polymers and one or more fillers. The polymer material may include any polymerizable material, such as a monomer and / or an oligomer.

[0009] Splitting the determined viscosity curve into the determined melting curve and the determined solidification curve and determining the corresponding fitting curves respectively can help to accurately estimate the viscosity of the polymer material at the corresponding temperature and heating rate. In other words, due to the splitting of the determined viscosity curve, the estimated value of the viscosity of the polymer material (e.g., the viscosity curve) obtained by a specific temperature and a specific heating rate can be closer to the actual viscosity.

[0010] According to one embodiment, the fitted curing curve is determined by estimating a curing degree curve for a corresponding heating rate and by determining the fitted curing curve according to the estimated curing degree curve. The curing degree curve may help to accurately determine the viscosity of the polymer material.

[0011] According to one embodiment, by determining the degree of cure of the polymer material (e.g., performing DSC analysis on the polymer material) and determining at least one linear dependence between the heating rate and the temperature inverse (e.g., from DSC analysis), the degree of cure curve is estimated. The linear dependence can be given by a straight line, wherein the straight line can be called a Qi curve. The linear dependence can be described by a chart comprising a straight line, wherein the chart can display the natural logarithm of the heating rate depending on the temperature inverse. DSC is a common method for determining the degree of cure, which can be easily and accurately performed. However, another method can also be performed to estimate the degree of cure, such as DEA (dielectric analyzer), FTIR (Fourier transform infrared spectroscopy), DMA (dynamic mechanical analyzer), etc.

[0012] According to one embodiment, the linear dependence is determined by estimating a fixed value that is independent of the degree of solidification; and the linear dependence is determined so that the corresponding straight line contains the fixed value. The fixed value can be called the Qi point. The use of the Qi point in the viscosity estimation allows accurate estimation of the viscosity curve at the corresponding temperature and heating rate. In other words, due to the participation of the Qi point, the estimated value of the viscosity curve of the polymer material obtained by a specific temperature and a specific heating rate can be closer to the true viscosity, as disclosed below, for example, with respect to the preferred embodiment.

[0013] According to one embodiment, the determined viscosity curve is split into the determined melting curve and the determined solidification curve at the respective minimum of the determined viscosity curve. The minimum viscosity is an exact value for each determined viscosity curve. Thus, the minimum viscosity is an exact value for splitting the determined viscosity curve into the determined melting curve and the determined solidification curve.

[0014] According to one embodiment, the determined viscosity curve is split into at least two determined melting curves; for each split melting curve, at least one fitted melting curve is determined; and a main melting curve is determined by combining the split melting curves; and the viscosity curve of the polymer material is estimated based on the main melting curve. For example, the determined viscosity curve is split into the determined solidification curve and a first determined melting curve and a second determined melting curve. The first determined melting curve can be referred to as α-melting, and the second determined melting curve can be referred to as β-melting. Providing two determined melting curves and determining the main melting curve based on the two determined melting curves can help to accurately determine the viscosity curve.

[0015] According to one embodiment, the main melting curve is determined by determining an average melting curve of the determined melting curves. This may facilitate accurate and / or simple determination of the main melting curve.

[0016] According to one embodiment, the main melting curve is fitted based on the Eyring equation; and the viscosity curve of the polymer material is determined based on the fitted main melting curve. The fitting of the main melting curve, especially the fitting based on the Eyring equation, can help to accurately determine the viscosity curve.

[0017] According to one embodiment, the maximum viscosity of the polymer material is determined from a plateau phase of a respective one of the determined curing curves. This may help to accurately determine the viscosity curve.

[0018] According to one embodiment, the determined curing curve from which the maximum viscosity is derived is the determined curing curve at the lowest heating rate. This may help to accurately determine the viscosity curve.

[0019] According to one embodiment, the fitted line of the heating rate at 0% curing corresponds to the temperature at minimum viscosity. This can help to accurately determine the viscosity curve.

[0020] According to one embodiment, the fitting line for the heating rate is determined by determining the starting temperature at each heating rate and adding the determined starting temperature to the straight line representing the linear dependence. This can help to accurately determine the viscosity curve.

[0021] According to one embodiment, the temperature at which the minimum viscosity occurs is determined according to a given heating rate; the minimum viscosity is selected from the viscosities measured at different heating rates; and the minimum temperature is fitted to the minimum viscosity according to the Eyring equation. This can help to accurately determine the viscosity curve.

[0022] According to one embodiment, the Eyring equation is applied to determine two or more fitted melting curves for each of the determined melting curves. This may help to accurately determine the viscosity curve.

[0023] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0025] Figure 1 A flow chart illustrating an exemplary embodiment of a method for estimating a viscosity curve of a polymeric material;

[0026] Figure 2 shows examples of viscosity values ​​of polymer materials at different temperatures obtained at different heating rates;

[0027] Figure 3 shows examples of several melting curves for polymer materials at different heating rates;

[0028] Figure 4 shows examples of several curing curves for polymer materials at different heating rates;

[0029] Figure 5 A flow chart illustrating an exemplary embodiment of a method for estimating the QI point of a given polymer material;

[0030] Figure 6 shows examples of DSC thermograms of polymer materials at different heating rates;

[0031] Figure 7 An example of a graph showing the degree of cure of a polymer material as a function of temperature at different heating rates under non-isothermal conditions is shown;

[0032] Figure 8 An example of an Ozawa-Flynn-Wall plot is shown;

[0033] Fig. 9 An example of the distribution of several intersections is shown;

[0034] Fig.10 Shown according to Fig. 9 A detailed view of the intersection between 10% and 90%;

[0035] Fig.11 An example of a Qi curve in a Qi curve diagram is shown;

[0036] Fig.12 Shown according to Fig.11 Detailed view of the QI curve;

[0037] Fig.13 A flow chart illustrating an exemplary embodiment of a method of determining a graph of degree of conversion values ​​for estimating the degree of conversion of a polymer material under non-isothermal conditions;

[0038] Fig.14 shows a graph including an exemplary plot of degree of conversion values ​​as a function of temperature under non-isothermal conditions;

[0039] Fig.15 Examples of several melting curves and average melting curves for polymer materials are shown;

[0040] Fig.16 An example of a principal melting curve of a polymer material fitted by an average melting curve is shown;

[0041] Fig.17 An example of a fitted curve for fitting the minimum viscosity is shown for the lowest temperature.

[0042] Fig.18 A detailed flow chart of an exemplary embodiment of a method for estimating a viscosity curve of a polymer material is shown.

[0043] The reference symbols used in the drawings and their meanings are listed in summary form in the reference symbol list. In principle, identical components in the figures are provided with the same reference symbols. DETAILED DESCRIPTION

[0044] Figure 1 A flow chart of an exemplary embodiment of a method for estimating a viscosity curve of a polymeric material is shown. The polymeric material may include one or more polymers, or a mixture of one or more polymers and one or more fillers. The polymeric material may include any polymerizable material, such as a monomer and / or an oligomer.

[0045] In step S2 , viscosity values ​​of the polymer material are obtained at different temperatures T under different heating rates β. The viscosity values ​​can be obtained by heating the polymer material at different heating rates β and measuring the viscosity of the polymer material at different temperatures T.

[0046] In step S4, at least one viscosity curve of the polymer material is determined from the viscosity measured for each heating rate β. Figure 2 An example of a corresponding viscosity curve is shown in FIG. The viscosity curve can be determined by connecting the measured viscosity values ​​in the corresponding graph, for example Figure 2 The viscosity value at the start of the measurement can correspond to Figure 2 The first feature point A is shown.

[0047] In step S6 , for each determined viscosity curve, the viscosity curve is split into at least one determined melting curve and at least one determined solidification curve. Figure 3 Several examples of corresponding melting curves are shown in . Figure 4 . Optionally, as described later, the determined viscosity curve may be split into two or more determined melting curves and one determined solidification curve. For example, for two melting curves, the first melting curve may extend from a first characteristic point A of the determined viscosity curve to a second characteristic point B, and the second melting curve may extend from a second characteristic point B of the determined viscosity curve to a third characteristic point C.

[0048] Optionally, the determined viscosity curve may be split into the determined melting curve and the determined solidification curve at the corresponding minimum of the determined viscosity curve, wherein the minimum is at Figure 2 The third characteristic point C is shown in FIG. The minimum viscosity η min is the exact value for each determined viscosity curve. The minimum viscosity η can be determined for a given heating rate β min Temperature at which the minimum viscosity η min The viscosity can be selected from the viscosity measured at different heating rates β. According to the Eyring equation, the minimum temperature T min With minimum viscosity η min Fitting:

[0049]

[0050] Where η is the dynamic viscosity, h is Planck's constant, N A is Avogadro's constant, V m is the molar volume of the polymer material, E0 is the viscous flow activation free energy, and R is the gas constant.

[0051] Optionally, the Eyring equation can be applied to determine two or more fitted melting curves for each of the determined melting curves. In particular, the determined viscosity curve can be split into at least two determined melting curves. At least one fitted melting curve can be determined for each split melting curve. Then, a main melting curve can be determined by combining the split melting curves. The viscosity curve of the polymer material can be determined based on the main melting curve. For example, the determined viscosity curve is split into a determined solidification curve and a first determined melting curve and a second determined melting curve. The first determined melting curve can be called α melting, for example, between characteristic points A and B, and the second determined melting curve can be called β melting, for example, between characteristic points B and C.

[0052] The master melting curve may be determined by determining an average melting curve of the determined melting curves. Fig.15 An example of a corresponding average melting curve is shown in . The master melting curve can then be fitted based on the Eyring equation, for example as Fig.16 Then, the viscosity curve of the polymer material can be estimated based on the fitted main melting curve.

[0053] Alternatively, the maximum viscosity η of the polymer material may be determined according to a stable phase of one of the corresponding determined curing curves. max For example, the maximum viscosity η is selected from max The determined curing curve may be the determined curing curve at the lowest heating rate β.

[0054] In step S8, at least one fitted melting curve is determined for each determined melting curve. Fig.16 Several examples of the corresponding fitted melting curves are shown in .

[0055] In step S10 , at least one fitted curing curve is determined for each determined curing curve. Fig.14 Several examples of correspondingly fitted curing curves are shown in FIG. The fitted curing curve can be determined by estimating the curing degree curve for the corresponding heating rate β and determining the fitted curing curve based on the estimated curing degree curve. The curing degree curve can help to accurately determine the viscosity of the polymer material. Fig.13 Explain the method to determine the degree of cure curve.

[0056] In particular, the polymer material can be analyzed by performing DSC analysis (see Figure 6 ) and determine from DSC analysis at least one linear dependence between the heating rate β and the inverse temperature 1 / T ( Figure 8 and Fig.11 ), to estimate the degree of cure curve. The linear dependence can be given by a straight line, which can be called a Qi curve. The linear dependence can be described by a graph containing a straight line, which can show that the heating rate β depends on the natural logarithm of the inverse temperature 1 / T.

[0057] The linear dependence can be determined by estimating a fixed value that is independent of the degree of solidification, and the linear dependence can be determined so that the corresponding straight line contains the fixed value. This fixed value can be called the Qi point. The Qi point can be determined by referring to Figure 5 Explanation method to determine.

[0058] Alternatively, the fitting line of the heating rate β at a curing degree of 0% may correspond to the minimum viscosity η minAlternatively or additionally, the starting temperature T at each heating rate β can be determined 起始 And determine the starting temperature T 起始 Added to the straight line representing the linear dependence, a fitted line for the heating rate β is determined.

[0059] In step S12, the viscosity curve of the polymer material is estimated by combining the fitted melting curve(s) and the corresponding fitted solidification curve(s).

[0060] Figure 2 Examples of viscosity values ​​η of a polymer material obtained at different temperatures T at different heating rates β are shown, in particular as examples of determined viscosity curves. Figure 1 In the method explained, corresponding viscosity curves can be determined, wherein corresponding viscosity values ​​η can be acquired at different heating rates β, so that a viscosity curve can be determined for each heating rate β.

[0061] The starting point of the β melting of the viscosity curve corresponding to a heating rate β=5 K / min is given at the characteristic point B. The starting temperature T 起始 and initial viscosity η 起始 are the temperature and viscosity at the characteristic point B, respectively, and are defined by the method described in claim 1.

[0062] Curing starts at the characteristic point C of the viscosity curve corresponding to a heating rate β=5 K / min. Minimum temperature T min and minimum viscosity η min are the temperature and viscosity at the characteristic point C, respectively, and are defined by the method described in claim 1.

[0063] Maximum viscosity η before decomposition begins max The maximum viscosity η is given at the characteristic point D of the viscosity curve corresponding to a heating rate β = 5 K / min. max Depending on the heating rate β, the theoretical maximum viscosity of the polymer material may not yet be reached (at Figure 2 shown in the figure).

[0064] Figure 3 Examples of several determined melting curves of polymer materials are shown. The determined melting curves represent alpha melting, in particular alpha melting between corresponding characteristic points A and B of the corresponding viscosity curve. Figure 3 The melting curves shown in are determined by the above-described measurements and resolution of the corresponding determined viscosity curves.

[0065] Figure 4Examples of several determined curing curves for polymer materials are shown. The determined curing curves may extend from the corresponding characteristic point C to the corresponding fourth characteristic point D (see Figure 2 ).from Figure 4 The minimum viscosity η can be extracted from min ,For example

[0066] η min =1972.8Pa·s, β=1K / min,

[0067] η min =255.0Pa·s, β=5K / min,

[0068] η min =89.6Pa·s, β=10K / min,

[0069] η min =61.5Pa·s, β=15K / min.

[0070] Figure 5 The estimated Qi point QI of polymer materials is shown in Fig.11 ) is a flowchart of an exemplary embodiment of a method.

[0071] In step S20, n different heating rates β can be used. n =[β 0， β1,…,β n-1 ] Perform differential scanning calorimetry (DSC) measurement on the probe of the polymer material under , wherein n is a natural number. For example, n can be 1 to 20, such as 1 to 10, such as 3 to 6.

[0072] Figure 6 An example of a DSC thermogram 20 of a polymer material determined by a DSC measurement is shown. The DSC thermogram 20 may include one plot for each heating rate β, where the heating rate β n The unit is K / min. Alternatively, the heating rate β can be given in any other possible temperature-time relationship, such as °C / s or °F / h.

[0073] The degree of cure value α of the degree of cure can be determined based on the DSC thermogram 20, wherein the degree of cure value α can be determined by the following formula:

[0074]

[0075] Among them, H Total is the energy absorbed by the polymer material until the solidification of the polymer material is completed, H Total Corresponds to Figure 2 The area below the corresponding figure in H Tis the energy absorbed by the polymer material until it reaches temperature T, H T Corresponds to Figure 2 The area from the leftmost side to temperature T below the corresponding graph.

[0076] In step S22, for each heating rate β i Determine the curing degree value α = [0, 0.01, ..., 100] (a total of 10001 elements) and the corresponding temperature T i =[T i,0 ,T i,1 ,...,T i,1000 ], where i=0, 1,…, m-1 are natural numbers.

[0077] Figure 7 An example of a graph is shown, which may be referred to hereinafter as a first graph 22. The first graph 22 shows the heating rate β under non-isothermal conditions. n， According to the temperature T i Determine the value of the degree of solidification of the polymer material α. Figure 3 It can be seen that the degree of curing is a function of the heating rate β and the temperature T.

[0078] ∝=∝(β,T).

[0079] For example, the dashed horizontal line in the first graph 22 may correspond to a curing degree value α of 50%, ie α=50%, wherein the intersection of the graph of the curing degree α and the dashed horizontal line represents the temperature T at which the curing degree value is 50% at the corresponding heating rate β.

[0080] Figure 8 An example of an Ozawa-Flynn-Wall graph is shown, which may be referred to as a second graph 24. The second graph 24 may be implemented by Ozawa-Flynn-Wall analysis known in the art. Figure 4 The Ozawa-Flynn-Wall diagram can be obtained from Figure 3 The heating rate β is extracted from the diagram by the corresponding horizontal line n and temperature T are constructed for a degree of curing α=50%.

[0081] The Ozawa-Flynn-Wall diagram may also include correspondingly constructed diagrams for other degrees of cure α = [0, 0.01, ..., 100]. However, the corresponding diagrams constructed according to the traditional Ozawa-Flynn-Wall analysis may intersect each other in a certain area of ​​the Ozawa-Flynn-Wall diagram (not shown in the figure), which is meaningless from a physical point of view, indicating the defects of the traditional Ozawa-Flynn-Wall analysis. Therefore, instead of using the traditional Ozawa-Flynn-Wall analysis, the inventors have found a more accurate method for constructing a diagram for predicting the degree of cure α of a given polymer material, as described below.

[0082] In step S24, according to all the above temperatures T i , heating rate β n and curing degree α = [0,0.01,…,100] to draw the graph in the Ozawa-Flynn-Wall diagram

[0083]

[0084] For example, j = 0, 1, ..., 10000. Therefore, the corresponding graph (which may be called Qi curve graph) may contain 10001 graphs, for example.

[0085] In step S26, a linear fit can be performed on the graph of the Qi curve, and the slope and intercept of the corresponding fitted graph (i.e., the Qi curve) relative to the y-axis can be extracted to obtain a slope K=[k0, k1, ..., k 10000 ] and the intercept B = [b0, b1, ..., b 10000 ].

[0086] In step S28, the intersection of the fitted graph with a curing degree value α between 1% and 30% (e.g., between 5% and 15%, e.g., α=10%) and all other fitted graphs can be determined, for example, by the following formula:

[0087]

[0088] In step S30, the intersection of the fitting graph with a curing degree value α between 30% and 60% (e.g., between 40% and 55%, e.g., α=50%) and all other fitting graphs can be determined, for example, by the following formula:

[0089]

[0090] In step S32, the intersection of the fitting graph with a curing degree value α between 70% and 99% (e.g., between 85% and 95%, e.g., α=90%) and all other fitting graphs can be determined, for example, by the following formula:

[0091]

[0092] In step S34, the intersection points determined in steps S10 to S14 may be plotted in a third diagram 26, for example as shown in FIG. Fig. 9 shown.

[0093] Fig. 9 The distribution of the above-mentioned intersections is shown in the third diagram 26. Fig. 9 It can be seen that 80% of the crossover points are located near the temperature inverse 0, where the temperature inverse 0 can only be achieved when the temperature T tends to infinity.

[0094] Fig.10 A detailed view of the intersection point between 10% and 90% is shown in a fourth diagram 36 .

[0095] In step S36, the intersection point of the fitting graph at 1 / T=0 may be determined as the Qi point QI, where QI=(0, lnβ).

[0096] Fig.11 An example of Qi curves is shown in the fifth graph 38, all of which include a Qi point QI. Except for the Qi point QI, the Qi curves do not intersect each other, which is completely reasonable from a physical point of view.

[0097] Fig.12 Shown according to Fig.11 Detailed view of the QI curve of FIG. 38 , in particular a view of the lower region 28 of the fifth graph 38 .

[0098] Fig.11 and Fig.12 The Qi curve can be determined through steps S38 and S40.

[0099] In step S38, the Qi point QI is used and according to the Ozawa-Flynn-Wall equation

[0100]

[0101] Draw the graph again (i.e., the Qi curve), where the term (-E α / R) defines the slope, R is the ideal gas constant, and the term defines the intercept of the corresponding curve, and A is the pre-exponential factor in [1 / s].

[0102]

[0103] For example, j=0,1,...,10000.

[0104] In step S40, a linear fit can be performed again on the Qi graph to obtain a Qi curve corresponding to the Ozawa-Flynn-Wall curve including the Qi point QI, and the corresponding adjusted slope K'=[k'0, k'1, ..., k' 10000 ] and the intercept B' = [b'0, b'1, ..., b' 10000 ].

[0105] Fig.13 A flow chart showing an exemplary embodiment of a method for determining a graph of a degree of conversion value for estimating the degree of conversion of a polymer material under non-isothermal conditions. The degree of conversion may be a degree of curing. The method may use the predetermined degree of curing value α i , heating rate β and the determined Qi point QI, and it can be determined to reach the predetermined curing degree value α i The corresponding temperature T of the solidification degree is estimated in the form of a mathematical function based on the temperature T and / or a corresponding diagram. i The continuous progression and / or trend of one or more degree of solidification values ​​α at one or more desired and / or arbitrary temperatures T can then be extracted by means of mathematical functions and / or from corresponding diagrams.

[0106] In step S50, a given heating rate β is received for which a graph of curing degree values ​​α representing the curing degree of the polymer material versus temperature T is estimated. The heating rate β may be input into a device for determining a graph estimating the curing degree values ​​α, which may receive the heating rate β.

[0107] In step S52, the index i and the curing degree value α i are set to 0 respectively, the device receives the above-mentioned curing degree value α i＝ [0, 0.01, ..., 100] and the above Qi point QI = (0, lnβ). In addition, the slope of the graph can be given as the above function f(α).

[0108] In step S54, T i It can be determined by the following formula

[0109]

[0110] In step S56, the index i is increased by 1, that is, i=i+1, and the next conversion degree value α is selected. i , for example, by α i =α i-1 +δα is selected, where δα can be 1, for example.

[0111] In step S58, check the current conversion degree value α iIs it greater than 100. If the condition of step S58 is not met, the method may proceed to step S54. If the condition of step S58 is met, the method may proceed to step S60.

[0112] In step S60, a graph showing the change of the curing degree α with the temperature T may be drawn, for example, Fig.14 As shown, and / or the method for determining a graph of a degree of conversion value α for estimating a degree of conversion of a polymer material under non-isothermal conditions may be terminated.

[0113] The above method for determining a graph of a conversion value α for estimating the conversion degree of a polymer material under non-isothermal conditions can be used as a subroutine of a method for estimating a viscosity curve of a polymer material under non-isothermal conditions, such as in combination with Figure 1 described.

[0114] Fig.14 A graph including exemplary graphs of degree of conversion values ​​α as a function of temperature T under non-isothermal conditions, in particular for different given heating rates β, is shown. This graph may be referred to as the sixth graph 40. The sixth graph 40 may be determined by the above-described method for determining a graph of degree of conversion values ​​α for estimating the degree of conversion of a polymer material under non-isothermal conditions.

[0115] Fig.15 Examples of several determined melting curves and average melting curves for polymer materials are shown. In particular, Fig.15 Can correspond to Figure 3 , in addition to the average melting curve. The average melting curve can be determined based on several determined melting curves by any known averaging method. The average melting curve can be provided for the piecewise fitting procedure.

[0116] Fig.16 An example of a principal melting curve of a polymer material fitted by an average melting curve is shown. The principal melting curve can be determined from the average melting curve by piecewise fitting based on the Eyrings equation, which is known in the art.

[0117] Fig.17 shows the minimum temperature T min Fitting minimum viscosity η min The fitting curve can be referred to as the seventh graph 42.

[0118] In particular, for a given heating rate β, the minimum viscosity η min The temperature T at which the temperature is determined is based on the relationship given by the Qi curve. Then, the minimum viscosity η is selected from the above measurements. min , that is, the minimum viscosity η at the characteristic point C min After that, the minimum viscosity η was fitted by the Eyring equation min The temperature at that time.

[0119] Fig.18 A detailed flow chart of an exemplary embodiment of a method for estimating a viscosity curve of a polymer material is shown. In particular, reference is made to Fig.18 , explains a very complex method for estimating viscosity curves, with reference to Figure 1 A more general approach to explanation could include Fig.18 Therefore, the above diagrams and calculations also apply to Fig.18 The present invention is described in detail below, wherein repeated contents are omitted in order to provide a concise description of the present invention.

[0120] In step S70 , viscosity curves depending on temperature T at different heating rates β may be determined.

[0121] In step S72, the minimum viscosity η at different heating rates β can be determined according to the determined viscosity curve. min .

[0122] In step S74, the maximum viscosity η can be determined for all heating rates β. max .

[0123] In step S76, the determined melting curve may be extracted from the determined viscosity curve.

[0124] In step S78, the determined curing curve may be extracted from the determined viscosity curve.

[0125] In step S80, an alpha melting curve may be determined according to the determined melting curve.

[0126] In step S82, a β melting curve may be determined according to the determined melting curve.

[0127] In step S84, a Qi curve may be determined according to the determined curing curve.

[0128] In step S86 , a curing degree value α as a function of the heating rate β and the temperature T may be determined.

[0129] In step S88, the viscosity η for the α melting curve can be determined based on the α melting curve using the Eyring equation, which is as follows:

[0130]

[0131] In step S90, the starting temperature T at different heating rates β can be determined based on the viscosity η for the α melting curve and the β melting curve. 起始 .

[0132] In step S92, the starting temperature T at different heating rates β can be起始 And the Qi curve determines the starting temperature T 起始 The heating rate β.

[0133] In step S94, the minimum temperature T min (It is the minimum viscosity η min The heating rate β is the temperature at which the

[0134] In step S96, the viscosity η for the α melting curve and depending on the starting temperature T 起始 The heating rate β determines the initial viscosity η 起始 , as shown below

[0135]

[0136] In step S98, the minimum viscosity η can be determined according to the determined minimum viscosity η at different heating rates β. min and depends on the minimum temperature T min The minimum viscosity η is determined by using the Eyring equation. min ,

[0137]

[0138] In step S100, the initial viscosity η 起始 and minimum viscosity η min And use the Eyring equation to estimate the viscosity η of the β melting curve,

[0139]

[0140] In step S102, the minimum viscosity η min , minimum viscosity η at different heating rates β min and the maximum viscosity η at all heating rates β max To estimate the viscosity η for the cure curve, it is as follows

[0141] η 固化 =α(β,T)·(η max -η min )+η min .

[0142] In step S104, the estimated melting curve and the estimated solidification curve are connected to form an estimated viscosity curve. In other words, the estimated viscosity curve can be provided by the estimated melting curve and the estimated solidification curve.

[0143] Although the present invention has been illustrated and described in detail in the drawings and the above description, these illustrations and descriptions should be regarded as illustrative or exemplary rather than restrictive; the present invention is not limited to the disclosed embodiments. Those skilled in the art can understand and implement other variations of the disclosed embodiments and implement the claimed invention by studying the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" / "an" does not exclude a plurality. A single processor or controller or other unit may perform the functions of several items described in the claims. The fact that certain measures are cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be interpreted as limiting the scope.

[0144] Reference Symbols List

[0145] 20 DSC thermogram

[0146] 22 First Chart

[0147] 24 Second Chart

[0148] 26 Third Chart

[0149] 28 Lower area

[0150] 30 Isotherms

[0151] 32 Non-isothermal

[0152] 36 Fourth Chart

[0153] 38 Fifth Chart

[0154] 40 Sixth Chart

[0155] 42 Seventh Chart

[0156] QI Qi point

[0157] AC feature points

[0158] S2-S104 Step 2 to step 104.

Claims

1. A method for estimating a viscosity curve of a polymer material, the method comprising: Obtaining viscosity values ​​of the polymer material at different temperatures (T) at different heating rates (β); determining at least one viscosity curve for the polymeric material based on the viscosity measured for each heating rate (β); For each determined viscosity curve, splitting the viscosity curve into at least one determined melting curve and at least one determined solidification curve; For each determined melting curve, determining at least one fitted melting curve; For each determined cure curve, determining at least one fitted cure curve; as well as The viscosity curve of the polymer material is estimated by combining the fitted melting curve and the fitted solidification curve.

2. The method according to claim 1, wherein: The fitted curing curve is determined by estimating a curing degree curve for a corresponding heating rate (β) and determining the fitted curing curve based on the estimated curing degree curve.

3. The method according to claim 2, wherein: The degree of cure curve is estimated by determining the degree of cure of the polymer material and determining at least one linear dependency between the heating rate (β) and the inverse temperature.

4. The method according to claim 3, wherein: determining the linear dependence by estimating a fixed value that is independent of the degree of cure; and The linear dependency is determined such that the corresponding straight line contains the fixed value.

5. The method according to any one of the preceding claims, wherein: At the corresponding minimum value (η min ), splitting the determined viscosity curve into the determined melting curve and the determined solidification curve.

6. The method according to any one of the preceding claims, wherein: splitting the determined viscosity curve into at least two determined melting curves; For each split melting curve, determining at least one fitted melting curve; determining a master melting curve by combining the resolved melting curves; and The viscosity curve of the polymer material is estimated from the main melting curve.

7. The method according to claim 6, wherein: The master melt curve is determined by determining an average melt curve of the determined melt curves.

8. The method according to claim 7, wherein: Fitting the main melting curve based on the Eyring equation; and The viscosity curve of the polymer material is determined from the fitted primary melting curve.

9. The method according to any one of the preceding claims, wherein: The maximum viscosity of the polymer material is determined from a plateau of a respective one of the determined curing curves.

10. The method according to claim 8, wherein: The determined cure curve from which the maximum viscosity is taken is the determined cure curve having the lowest heating rate (β).

11. The method according to any one of the preceding claims, wherein: The fitting line of the heating rate (β) for a curing degree of 0% corresponds to the minimum viscosity (η min ) at the temperature.

12. The method according to claim 11, wherein: By determining the starting temperature (T 起始 ) and determine the starting temperature (T 起始 ) is added to the straight line representing the linear dependence to determine the fitted line for the heating rate (β).

13. The method according to any one of claims 8 to 12, wherein: Determine the minimum viscosity (η) for a given heating rate (β) min ) at the time of The minimum viscosity (η) is selected from the viscosities measured at different heating rates (β). min );and According to the Eyring equation, the minimum temperature (T min ) and minimum viscosity (η min ) fitting.

14. The method according to any one of claims 8 to 13, wherein: The Eyring equation is applied to determine two or more fitted melting curves for each of the determined melting curves.

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