Preparation method and process of polypropylene material free-treatment ink

Abstract

The application provides a preparation method and process of a polypropylene material free-treatment ink, and relates to the technical field of ink, wherein the preparation method comprises the following steps: collecting an acid gas capture state parameter, generating an acid gas capture index through the state parameter; collecting a lamellar barrier structure parameter, generating a lamellar barrier order degree index through the lamellar barrier structure parameter; generating a synergistic stability index based on the acid gas capture index and the lamellar barrier order degree index, and combining the viscosity recovery rate of dispersed barium titanate; measuring the film coating hundred-grid adhesion grade, Shore hardness, gel content and phenolic resin related parameters, and combining the acid gas capture index, the lamellar barrier order degree index and the synergistic stability index to generate a resin interface strengthening index. The application inhibits CPP degradation through the cooperation of barium carbonate neutralization acid, mica barrier and barium titanate; the adhesion and aging resistance are improved by combining phenolic resin strengthening and quantitative threshold, and there is no harmful stabilizer, which is environmentally friendly and safe.

Description

Technical Field

[0001] This invention relates to the field of ink technology, specifically to a method and process for preparing a treatment-free ink made of polypropylene material. Background Technology

[0002] Polypropylene (PP) materials have low surface energy and high crystallinity, making it difficult for inks to adhere to their surface. Traditional processes require surface treatment through methods such as corona discharge, flame treatment, or primer coating. To simplify the process, the industry has developed treatment-free inks using chlorinated polypropylene (CPP) as the main binder resin. These inks leverage the structural similarity between CPP and the polypropylene substrate to achieve direct adhesion. However, as a core binder, CPP is prone to releasing hydrogen chloride and undergoing autocatalytic degradation under light, heat, and acidic conditions, leading to a continuous decline in adhesion and cohesion. Therefore, a systematic method is needed to address the self-corrosion and thermal instability issues of CPP, control its degradation behavior, and ensure the ink's shelf life and service reliability.

[0003] In the prior art, CN107699045B discloses a screen printing ink for polypropylene materials and its preparation method. This technology includes: 25-35 parts of polypropylene resin; 18-26 parts of solvent; 16-24 parts of pigment; 0.3-0.8 parts of dispersant; 0.3-0.8 parts of leveling agent; and 20-30 parts of filler. The screen printing ink using this method eliminates the need for surface treatment of polypropylene products before printing, allowing for direct printing. This avoids the adverse effects of surface treatment agents, flame coating, and corona treatment on the product's appearance, saving costs. The ink exhibits good adhesion, stable performance, and meets the requirements for product appearance.

[0004] However, in the aforementioned existing technologies, chlorinated polypropylene is prone to dehydrochlorination degradation under light, heat, and acidic conditions. The released hydrogen chloride gas can trigger an autocatalytic chain reaction, leading to thickening and particle precipitation during ink storage, continuous degradation of adhesion, and corrosion of printing equipment. Simultaneously, in a hot and oxygen-rich environment, the cohesion of the coating film decreases, resulting in cracking and peeling. Current methods often improve this by adding organotin or metallic soap heat stabilizers. However, organotin agents pose environmental compliance risks, metallic soaps have limited compatibility with the system, and there is a lack of quantifiable batch stability evaluation methods. Formula adjustments rely on experience, making it difficult to achieve stable industrial-scale quality control.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a method and process for preparing polypropylene ink without treatment, thereby solving the problems mentioned in the background art. This invention utilizes barium carbonate to neutralize hydrogen chloride, mica to construct a barrier network, and barium titanate for synergistic dispersion to form a triple protection, effectively inhibiting the degradation of chlorinated polypropylene. Combined with phenolic resin interface strengthening and quantification threshold determination, it ensures ink adhesion, heat and oxygen aging resistance, and batch stability, avoiding the use of harmful stabilizers, making it environmentally friendly and safe.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for preparing a treatment-free ink for polypropylene material includes the following steps:

[0009] S1: Collect acid gas capture state parameters, including: the volume of NaOH consumed after heating the blank CPP sample, the volume of NaOH consumed after heating the barium carbonate sample, and the mass of barium carbonate filler; generate an acid gas capture index based on the state parameters, which is used to quantitatively evaluate the in-situ neutralization efficiency of barium carbonate on hydrogen chloride released from the degradation of chlorinated polypropylene, and determine the minimum effective amount of barium carbonate to be added.

[0010] S2: Collect parameters of the sheet barrier structure, including: half-peak width of mica characteristic diffraction peaks, oxygen permeability of the coating film, and mass fraction of mica functional filler; generate a sheet barrier order index based on the sheet barrier structure parameters to quantitatively characterize the order and density of the barrier network formed by mica sheets in the resin matrix, and evaluate the physical barrier capability against the diffusion of heat, oxygen, and corrosive gases.

[0011] S3: Based on the acid gas capture index and the orderliness index of the lamellar barrier, combined with the viscosity recovery rate after the barium titanate dispersion, a synergistic stability index is generated to quantify the synergistic protective effect of the three mechanisms of chemical absorption, physical barrier and inert isolation, and to adjust the amount of barium titanate until the standard is met.

[0012] S4: Measure the coating adhesion grade, Shore hardness, gel content, and phenolic resin-related parameters, and combine them with the acid gas capture index, lamellar barrier order index, and synergistic stability index to generate the resin interface strengthening index, which is used to comprehensively evaluate the degree of compensation of phenolic resin for coating adhesion and cohesion; compare the resin interface strengthening index with the preset qualified threshold and make production judgment.

[0013] Furthermore, the acid gas capture index is calculated using the following formula:

[0014]

[0015] in: The acid gas capture index;

[0016] The volume of NaOH consumed after heating the blank CPP sample;

[0017] The volume of NaOH consumed after heating the barium carbonate sample;

[0018] For the quality of barium carbonate filler;

[0019] As the benchmark quality;

[0020] The effective capture rate of acid; This represents the marginal contribution coefficient of the added amount.

[0021] Furthermore, after the acid gas capture index is calculated using the formula, it is first compared with a preset first threshold. If the acid gas capture index is greater than or equal to the first threshold, it indicates that the barium carbonate filler has achieved the expected in-situ chemical neutralization ability of hydrogen chloride released from the degradation of chlorinated polypropylene at a given addition amount, and the corresponding filler ratio is qualified, so the subsequent measurement steps can continue. If the acid gas capture index is lower than the first threshold, it is determined that the current acid capture efficiency of barium carbonate is insufficient, and it is necessary to increase the mass fraction of barium carbonate and replace it with a barium carbonate specification with higher activity, and repeat the sampling, testing and index calculation steps until the first threshold condition is met.

[0022] Furthermore, the orderliness index of the sheet barrier is calculated using the following formula:

[0023]

[0024] in: The order index of the layer barrier;

[0025] The half-peak width of the characteristic diffraction peak of mica;

[0026] Oxygen permeability of the coating;

[0027] The mass fraction of mica functional filler;

[0028] To block denser factors; This is the packing adequacy coefficient.

[0029] Furthermore, the orderliness index of the sheet barrier is compared with a preset second threshold. If the orderliness index of the sheet barrier is greater than or equal to the second threshold, it indicates that the orderliness and density of the sheet barrier network formed by the mica functional filler in the chlorinated polypropylene matrix have reached the expected level, and the corresponding filler ratio and dispersion process are qualified, so subsequent measurements can continue. If the orderliness index of the sheet barrier is lower than the second threshold, it is determined that the orderliness of the mica sheet orientation and the density of the barrier are insufficient. It is necessary to adjust the mass fraction of the mica, improve the grinding and dispersion process, and select a mica variety with a larger aspect ratio. The film preparation, diffraction scanning, air permeability test and sheet barrier orderliness index calculation are then repeated until the second threshold condition is met.

[0030] Furthermore, the cooperative stability index is calculated using the following formula.

[0031]

[0032] in: It is a collaborative stability index;

[0033] Viscosity recovery rate;

[0034] This is the dispersion stability term; These are the weighting coefficients for the acid gas capture index, the sheet barrier order index, and the dispersion stability term, respectively, satisfying... .

[0035] Furthermore, the synergistic stability index is compared with a pre-set benchmark threshold range. When the synergistic stability index is within the benchmark threshold range, it is determined that the filler system composed of barium carbonate, mica functional filler, and barium titanate has formed effective synergistic protection in the three dimensions of chemical neutralization, physical barrier, and inert isolation, and the ink base material is allowed to proceed to the subsequent resin interface strengthening step. When the synergistic stability index is lower than the lower limit of the benchmark threshold range, it is determined that the synergistic protection effect of the filler system is insufficient. At this time, the dosage ratio and dispersion process parameters of barium carbonate, mica functional filler, and barium titanate need to be adjusted, and the acid gas capture index, lamellar barrier order index, and viscosity recovery rate should be re-measured until the calculated synergistic stability index meets the benchmark threshold range before proceeding with subsequent operations.

[0036] Furthermore, the relevant parameters of the phenolic resin include the mass fraction of phenolic resin added and the density of phenolic resin; the resin interface strengthening index is calculated using the following formula:

[0037]

[0038] in: The resin interface strengthening index;

[0039] It is the adhesion rating of 100 grid lines;

[0040] Shore hardness;

[0041] This refers to the gel content;

[0042] Add mass fraction to phenolic resin;

[0043] Density of phenolic resin;

[0044] This is a comprehensive term for interface mechanics; This refers to the crosslinking efficiency term. This is a collaborative benchmark factor.

[0045] Furthermore, the resin interface strengthening index is compared with a preset qualified threshold. When the resin interface strengthening index is not lower than the preset qualified threshold, it is determined that the filler and resin synergy system of the current batch of polypropylene treatment-free ink has met the requirements for corrosion resistance and heat resistance, the batch is qualified, and it is allowed to be put into mass production. When the resin interface strengthening index is lower than the preset qualified threshold, it is determined that the current batch of ink has a serious risk of self-corrosion and thermal instability. At this time, the phenolic resin has failed to effectively compensate for the loss of coating adhesion and cohesion caused by the degradation of chlorinated polypropylene. The batch is unqualified and is prohibited from being put into production. It is also suggested that the amount of phenolic resin added, the type of phenolic resin, the acid gas capture index, the order index of the layer barrier, and the comprehensive index of synergistic stability should be retrospectively checked and adjusted.

[0046] A preparation process using the above preparation method includes the following steps:

[0047] Resin dissolution and premixing: An ester solvent is added to a reaction vessel, followed by chlorinated polypropylene resin. The mixture is stirred at low speed until completely dissolved to obtain a resin solution. The resin solution is used for subsequent wetting and dispersion of pigments.

[0048] High-speed dispersion: Add pigments, dispersants and fillers to the resin liquid and disperse at a high speed of 1000-2000 rpm for 20-30 minutes to initially break up the pigment agglomerates and form a uniform slurry;

[0049] Fine grinding: The dispersed slurry is ground to a fineness of ≤10μm using a sand mill, with the temperature controlled at ≤50℃, to obtain a uniform and fine ink base material, ensuring the gloss and color strength of the coating film;

[0050] Formulation optimization and performance verification: The acid gas capture index, the sheet barrier order index, and the synergistic stability index were collected and compared with the threshold values ​​to determine the dosage of barium carbonate, mica, and barium titanate; then phenolic resin was introduced, the resin interface strengthening index was calculated and compared with the qualified threshold value to determine whether the formulation was qualified.

[0051] Filtration, defoaming, and packaging: Qualified ink is allowed to stand to defoam, then filtered through a 200-400 mesh filter to remove impurities, filled and sealed, and labeled with the batch number and performance indicators to obtain the finished polypropylene ink without treatment.

[0052] Compared with existing technologies, the advantages of this invention are as follows: Barium carbonate is used to neutralize hydrogen chloride released during the degradation of chlorinated polypropylene in situ, generating an acidic gas capture index to inhibit autocatalytic degradation; a barrier network is constructed using mica sheets, and the orderliness index of the sheet barrier enhances the resistance to heat and oxygen aging; barium titanate is introduced to characterize the inert isolation effect, forming a synergistic stability index, achieving the optimal match of the three mechanisms of chemical absorption, physical barrier, and inert isolation. Finally, phenolic resin is introduced to strengthen the interface, and the adhesion, hardness, and crosslinking density are comprehensively evaluated based on the resin interface strengthening index, effectively compensating for degradation losses. The entire method uses multi-index quantitative threshold determination, replacing empirical adjustments, ensuring batch stability and industrial quality control, and avoiding the use of harmful organotin stabilizers, making it environmentally friendly and safe. Attached Figure Description

[0053] Figure 1 This is a flowchart of a method for preparing a polypropylene material-free ink according to the present invention;

[0054] Figure 2 This is a schematic diagram illustrating the preparation process of a polypropylene material-free ink according to the present invention. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0056] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0057] Example:

[0058] Please see Figures 1-2 The present invention provides the following technical solutions:

[0059] A method for preparing a treatment-free ink for polypropylene material includes the following steps:

[0060] S1: Collect acid gas capture state parameters to provide a directly measurable data basis for subsequent calculation of the acid gas capture index. These parameters specifically include: the volume of NaOH (sodium hydroxide) consumed after heating a blank CPP (chlorinated polypropylene) sample. This parameter is obtained by heating a standard CPP sample without added barium carbonate in a closed reactor at a constant temperature, then absorbing and titrating the released hydrogen chloride gas with a standard sodium hydroxide solution, characterizing the total acid production from the degradation of CPP under heated conditions without a capture agent; the volume of sodium hydroxide consumed after heating a sample with added barium carbonate. This parameter is obtained by simultaneously heating and titrating a CPP sample with a known mass of barium carbonate filler under the same conditions, characterizing the corresponding amount of residual hydrogen chloride after in-situ neutralization with barium carbonate; and the mass of the barium carbonate filler, obtained by weighing using a precision balance. These parameters together constitute the acid gas capture state parameter set, providing raw data support for quantitatively evaluating the chemical inhibition ability of barium carbonate on the self-corrosion behavior of CPP.

[0061] The acid gas capture index is calculated using the following formula:

[0062]

[0063] in: The acid gas capture index;

[0064] The volume of NaOH consumed after heating the blank CPP sample;

[0065] The volume of NaOH consumed after heating the barium carbonate sample;

[0066] For the quality of barium carbonate filler;

[0067] As the benchmark quality;

[0068] For acid effective capture rate, This represents the volume difference of NaOH corresponding to the HCl neutralized by barium carbonate, divided by the total amount of acid released in the blank. The proportion of acid actually neutralized to the total amount of acid released is obtained. This value is between 0 and 1. The closer it is to 1, the more thoroughly barium carbonate captures HCl. The marginal contribution coefficient of the added amount is expressed in natural logarithmic form based on the logarithmic relationship between reactant concentration and reaction extent in chemical thermodynamics. Adding 1 also avoids the situation where... The appearance of meaningless negative infinity and the decrease in the growth rate of the logarithmic function with the increase of the amount added are consistent with the actual situation. When barium carbonate is added in excess, its marginal capture efficiency will gradually decrease due to the limited dispersibility.

[0069] To determine the amount of barium carbonate filler to be added to the ink formulation, a standard solution of chlorinated polypropylene resin was first prepared and divided equally into blank samples and several test samples. Different known masses of barium carbonate were added to each test sample. All samples were placed in a closed reactor and heated under constant temperature conditions to accelerate resin degradation and release hydrogen chloride gas. The released gas was absorbed and titrated with a standard sodium hydroxide solution, and the volume of titrant consumed by the blank sample and each test sample was recorded. The acid gas capture index value corresponding to each amount of barium carbonate added was calculated based on a pre-established acid gas capture index formula.

[0070] The acid gas capture index, calculated using a formula, is first compared with a preset first threshold. If the acid gas capture index is greater than or equal to the first threshold, it indicates that the barium carbonate filler, at the current addition amount, has achieved the expected level of in-situ chemical neutralization of hydrogen chloride gas released from the degradation of chlorinated polypropylene resin. The corresponding filler ratio is deemed qualified, and the added barium carbonate mass is determined as the fixed amount of barium carbonate component in the ink formulation. The subsequent layered barrier network order index determination step can then proceed. If the acid gas capture index is lower than the first threshold, it is determined that the current acid capture efficiency of the barium carbonate filler is insufficient and cannot meet the requirement for effective inhibition of acidic products from resin degradation. In this case, the relevant parameters of barium carbonate need to be adjusted. The adjustment methods include at least one of the following: increasing the mass fraction of barium carbonate in the formulation, or replacing it with a barium carbonate specification with higher activity. The higher activity barium carbonate specification refers to a barium carbonate product with a smaller particle size or a larger specific surface area. After completing the above adjustments, repeat the entire procedure specified in this step, including sampling, isothermal accelerated degradation, alkaline absorption titration, and index calculation. Compare the newly obtained acid gas capture index with the first threshold again. Repeat this iterative process until the acid gas capture index meets the threshold condition before proceeding to the next measurement step.

[0071] S2: Collect parameters of the mica sheet barrier structure, including: the half-width at half-maximum (WHM) of the mica characteristic diffraction peaks, the oxygen permeability of the coating film, and the mass fraction of the mica functional filler. The WHM of the mica characteristic diffraction peaks is obtained by scanning the dried coating sample with an X-ray diffractometer. The WHM of the mica (001) crystal plane characteristic diffraction peak is used as the parameter to characterize the regularity of the directional arrangement of the mica sheets in the coating substrate. The oxygen permeability of the coating film is obtained by measuring the same coating sample with an air permeability tester to quantify the coating film's ability to block oxygen permeation. The mass fraction of the mica functional filler is the percentage of mica filler in the dry film, determined by calculating the amount of material added according to the formula and the mass of the dried coating film.

[0072] The orderliness index of the sheet barrier is calculated using the following formula:

[0073]

[0074] in: The order index of the layer barrier;

[0075] The half-peak width of the characteristic diffraction peak of mica;

[0076] Oxygen permeability of the coating;

[0077] The mass fraction of mica functional filler;

[0078] To block denser factors, and Both are inverse indicators; their product is placed after taking the reciprocal of the denominator. The larger this factor, the stronger the blocking effect achieved under a given degree of order. (FWHM) A small value indicates that the layers are arranged neatly and orderly; oxygen permeability A small value indicates difficulty in gas penetration. When both are small, the product is even smaller, and the reciprocal is larger, indicating that the orderly arrangement of the packing material effectively translates into gas barrier capability. The square root form is used to reconcile the linear expectation that more filler leads to better barrier properties with the contradiction in practical applications where excessive addition can cause agglomeration and reduce the degree of order. The square root function grows faster in the low addition range and slower in the high addition range, which is consistent with the seepage threshold theory of mica sheets forming an effective barrier network.

[0079] After calculating the orderliness index of the mica barrier, the index is compared with a preset second threshold. If the orderliness index of the mica barrier is greater than or equal to the second threshold, it indicates that the mica functional filler has formed a mica barrier network in the chlorinated polypropylene matrix with the expected level of orderliness and density. This barrier network can effectively block the diffusion path of heat, oxygen and acid corrosive media inside the coating. It is confirmed that the current mass fraction of the mica functional filler and the grinding and dispersion process used meet the requirements, and the subsequent resin interface strengthening index determination step can be carried out. If the orderliness index of the mica barrier is lower than the second threshold, it is determined that the orientation order of the mica sheets in the chlorinated polypropylene matrix is ​​insufficient, the density of the formed barrier network does not meet the expectations, and it cannot provide a sufficient physical barrier effect. At this time, the formulation and process of the mica functional filler need to be adjusted. The adjustment methods include increasing the mass fraction of the mica functional filler, optimizing the grinding and dispersion process to enhance the directional arrangement of the sheets, and selecting mica varieties with a larger aspect ratio to enhance the barrier coverage of the sheets.

[0080] After adjustment, all operations must be repeated, including film preparation, X-ray diffraction scanning to obtain the full width at half maximum (FWHM) of mica characteristic diffraction peaks, air permeability testing to obtain the oxygen transmission rate of the coating, and calculation of the lamellar barrier order index, until the recalculated lamellar barrier order index meets the second threshold condition before proceeding to the next step. This determination mechanism ensures that the physical barrier capability of the filler system has been quantitatively verified before the introduction of phenolic resin for interface strengthening.

[0081] S3: With the acid gas capture index and the lamellar barrier order index both meeting their respective thresholds, and the amounts of barium carbonate and mica determined, different mass fractions of barium titanate filler were added to the ink base and fully dispersed to obtain a series of test samples. The initial viscosity of each sample was measured using a rotational viscometer, followed by high-shear homogenization and a specified settling time before measuring the recovery viscosity and calculating the viscosity recovery rate. The previously obtained acid gas capture index, lamellar barrier order index, and the currently measured viscosity recovery rate were substituted into a preset formula to calculate the synergistic stability index corresponding to each amount of barium titanate added. The synergistic stability index was calculated using the following formula.

[0082]

[0083] in: It is a collaborative stability index;

[0084] Viscosity recovery rate;

[0085] The dispersion stability term is expressed as viscosity recovery rate. As a core variable, adding 1 ensures that the logarithm argument is always greater than zero, avoiding... The calculation becomes meaningless when the data approaches zero. Using the natural logarithm ln allows for non-linear compression and smoothing of the data. It enhances the differentiation in the high-value area while amplifying the sensitivity in the low-value area, thus more sensitively reflecting the decrease in isolation effect caused by poor barium titanate dispersion; These are the weighting coefficients for the acid gas capture index, the sheet barrier order index, and the dispersion stability term, respectively, satisfying... .

[0086] The synergistic stability comprehensive index is compared with a pre-set benchmark threshold range. When the synergistic stability comprehensive index falls within the benchmark threshold range, it is determined that the ternary filler system composed of barium carbonate, mica functional filler and barium titanate has formed effective synergistic protection in the three functional dimensions of chemical neutralization, physical barrier and inert isolation. The components are reasonably matched and the overall formula of the filler system is qualified. It is allowed to transfer the current batch of ink base material to the subsequent resin interface strengthening step.

[0087] When the comprehensive index of synergistic stability is lower than the lower limit of the benchmark threshold range, it is determined that the synergistic protection effect of the ternary packing system is insufficient, indicating that there is a mismatch between the acid capture function of barium carbonate, the sheet barrier function of mica, and the inert isolation and dispersion function of barium titanate. At this time, the relevant parameters of the packing system need to be adjusted in a targeted manner. The adjustment methods include: adjusting the dosage ratio of at least one of barium carbonate, mica functional packing and barium titanate, optimizing the dispersion process parameters, or replacing it with a corresponding packing variety with higher activity.

[0088] After completing the above adjustments, repeat all the operations specified in the preceding steps, namely, re-measuring the acid gas capture index, the sheet barrier order index, and the viscosity recovery rate, and recalculating the synergistic stability comprehensive index by substituting them into the preset formula, and comparing it with the benchmark threshold range again. Repeat this iterative process until the newly obtained synergistic stability comprehensive index meets the benchmark threshold range before proceeding with the subsequent resin interface strengthening operation.

[0089] S4: Take several parts of ink base material, add rosin-modified phenolic resin according to different mass fractions, stir evenly and let stand to degas, then prepare a coating film on a standard polypropylene test piece, and dry at room temperature for a specified time; measure the cross-cut adhesion rating, Shore hardness, gel content, and relevant parameters of the phenolic resin, and combine them with the acid gas capture index, lamellar barrier order index, and synergistic stability index to generate the resin interface strengthening index; the cross-cut adhesion rating of the coating film is obtained by visually evaluating the coating film according to the standard rating table after drawing a grid on the coating film surface and peeling it with tape, and is used to quantify the coating film adhesion. The degree of adhesion between polypropylene substrates; Shore hardness, which is obtained by indenting the coating surface with a Shore hardness tester and is used to characterize the coating's ability to resist indentation deformation; gel content, which is obtained by immersing the coating sample in tetrahydrofuran until fully dissolved, drying and weighing the insoluble matter, and calculating its percentage of the original coating mass, and is used to quantify the density of the cross-linked network formed by phenolic resin and chlorinated polypropylene matrix; phenolic resin-related parameters include the mass fraction of phenolic resin added and the density of phenolic resin. The mass fraction of phenolic resin added is determined by the formulation feed ratio, and the density of phenolic resin is a physical constant of the resin itself.

[0090] The resin interface strengthening index is calculated using the following formula:

[0091]

[0092] in: The resin interface strengthening index;

[0093] It is the adhesion rating of 100 grid lines;

[0094] Shore hardness;

[0095] This refers to the gel content;

[0096] Add mass fraction to phenolic resin;

[0097] Density of phenolic resin;

[0098] This is a comprehensive term in interface mechanics, with a focus level of [missing information]. Using a 0-5 scale, the lower the level, the better the adhesion. The denominator is written as... Instead of using directly This is to avoid The denominator is zero at (optimal adhesion). Hardness It is placed in the molecule, therefore the better the adhesion ( The smaller the denominator and the higher the hardness (the larger the numerator), the larger the ratio of this item, which comprehensively reflects the coating's dual mechanical properties of resisting peeling and resisting indentation scratches; For cross-linking efficiency, This ratio represents the gel content produced per unit mass of phenolic resin, i.e., the crosslinking contribution efficiency of the resin. A higher ratio indicates a more complete crosslinking reaction between the phenolic resin and the system, resulting in a denser crosslinked network at the same addition amount. The logarithmic form also helps to smooth out fluctuations and avoid excessive influence from extreme values. As a synergistic benchmark factor, this factor directly incorporates the results of chemical capture and physical barrier into the interface strengthening evaluation, and normalizes it by dividing by CSI to ensure that the strengthening effect of phenolic resin is based on the full synergy of the filler system; when ACI and LBI are higher and CSI is reasonable, the same amount of phenolic resin can achieve higher strengthening efficiency.

[0099] The resin interface strengthening index is compared with the preset qualified threshold. When the resin interface strengthening index is not lower than the preset qualified threshold, it is determined that the filler system and resin reinforcement system of this batch of polypropylene treatment-free ink have formed an effective synergy. The coating film meets the requirements of corrosion resistance and heat aging resistance in terms of adhesion, hardness and cross-linking cohesive strength. This indicates that the rosin-modified phenolic resin has fully compensated for the interface strength loss that may be caused by the degradation of chlorinated polypropylene. The batch is qualified and can be put into mass production.

[0100] When the resin interface strengthening index is lower than the preset qualified threshold, the batch of ink is deemed to have a serious risk of self-corrosion and thermal instability. This indicates that the phenolic resin has failed to effectively compensate for the decrease in coating adhesion and cohesive strength caused by the degradation of chlorinated polypropylene. The batch is deemed unqualified, prohibited from production, and a non-conforming product diversion and alarm mechanism is triggered. Simultaneously, it is indicated that the following parameters need to be retrospectively checked and adjusted: the added mass fraction of phenolic resin, the type of phenolic resin, and the previously measured acid gas capture index, lamellar barrier order index, and synergistic stability comprehensive index. By retrospectively checking each of the above parameters, the root cause of the resin interface strengthening index failing to meet the standard should be identified. After completing the corresponding adjustments, the entire measurement and calculation process should be re-executed until the resin interface strengthening index meets the preset qualified threshold.

[0101] This embodiment also provides a preparation process using the above preparation method, including the following steps:

[0102] Resin Dissolution and Premixing: Measure the ester solvent according to the formula and add it to a jacketed, cooled, sealed reactor. Start low-speed stirring at 200-400 rpm. While stirring, slowly add chlorinated polypropylene resin powder, controlling the addition rate to prevent agglomeration. Continue stirring for 30-60 minutes, maintaining the system temperature at 40-50℃ as needed to promote dissolution, but not exceeding 60℃ to prevent resin degradation. Once the resin is completely dissolved into a transparent, homogeneous liquid, stop stirring. Take a sample and visually inspect for any undissolved particles; this is the resin solution. This resin solution serves as the continuous phase for subsequent pigment application, used to wet and support pigments and functional fillers.

[0103] High-speed dispersion: Add the prescribed amounts of dispersant, defoamer, organic pigment, and filler sequentially to the above resin solution. First, stir at a low speed of 300-500 rpm to initially wet the powder and avoid dust generation. Then, increase the stirring speed to 1000-2000 rpm and disperse at high speed for 20-30 minutes. During this process, use shear force to break up pigment agglomerates to below 30 μm and form a uniform paste. Cooling water should be turned on during dispersion to prevent excessive temperature rise, and attention should be paid to scraping and cleaning the walls to ensure no dead corners. After dispersion, take a sample and test it with a fineness tester. Only samples with a fineness ≤30 μm can proceed to the next process.

[0104] Fine grinding: The high-speed dispersed slurry is pumped into a horizontal sand mill for fine grinding via a diaphragm pump. The sand mill uses 0.6-1.2mm zirconia beads, with a filling rate of 70%-80% of the chamber volume. The main motor speed is 800-1200 rpm, and the grinding is carried out for 1-3 hours, while controlling the discharge temperature to ≤50℃. The ground ink base is fine and uniform, which can significantly improve the gloss, color strength, and printability of the coating film.

[0105] Formulation optimization and performance verification: Acid gas capture index, lamellar barrier order index, and synergistic stability index were collected and compared with preset thresholds to determine the minimum effective addition amounts of barium carbonate, mica, and barium titanate. The neutralization efficiency of barium carbonate for hydrogen chloride was calculated by heating titration. The orderliness of the mica lamellar barrier network was evaluated by X-ray diffraction and gas permeability testing. The inert isolation and dispersion effect of barium titanate was characterized by viscosity recovery rate. After the ternary filler system passed the test, rosin-modified phenolic resin was added, and parameters such as coating adhesion, hardness, and gel content were measured to calculate the resin interface strengthening index. The resin interface strengthening index was compared with the passing threshold to determine whether the formulation met the corrosion and heat resistance requirements; only qualified formulations could proceed to the final process.

[0106] Filtration, Defoaming, and Packaging: After passing quality control, allow the ink to stand for 20-30 minutes to allow large air bubbles to rise naturally. Then, filter the ink sequentially through a 200-mesh coarse filter and a 400-mesh fine filter to thoroughly remove grinding media debris, gel particles, and undispersed impurities. If small air bubbles remain, add a small amount of vacuum defoamer and stir slowly for 10 minutes. The filtered ink is then filled into clean, dry metal cans or plastic drums using a semi-automatic filling machine. Seal the containers immediately and affix a label to the outside, indicating the product model, batch number, viscosity, color, production date, and storage conditions. This yields the finished polypropylene pretreatment-free ink.

[0107] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0108] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution.

[0109] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0110] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for preparing a treatment-free ink for polypropylene materials, characterized in that, Includes the following steps: S1: Collect acid gas capture state parameters, including: the volume of NaOH consumed after heating the blank CPP sample, the volume of NaOH consumed after heating the barium carbonate sample, and the mass of barium carbonate filler; generate an acid gas capture index based on the state parameters, which is used to quantitatively evaluate the in-situ neutralization efficiency of barium carbonate on hydrogen chloride released from the degradation of chlorinated polypropylene, and determine the minimum effective amount of barium carbonate to be added. S2: Collect parameters of the sheet barrier structure, including: half-peak width of mica characteristic diffraction peaks, oxygen permeability of the coating film, and mass fraction of mica functional filler; generate a sheet barrier order index based on the sheet barrier structure parameters to quantitatively characterize the order and density of the barrier network formed by mica sheets in the resin matrix, and evaluate the physical barrier capability against the diffusion of heat, oxygen, and corrosive gases. S3: Based on the acid gas capture index and the orderliness index of the lamellar barrier, combined with the viscosity recovery rate after the barium titanate dispersion, a synergistic stability index is generated to quantify the synergistic protective effect of the three mechanisms of chemical absorption, physical barrier and inert isolation, and to adjust the amount of barium titanate until the standard is met. S4: Measure the coating adhesion grade, Shore hardness, gel content, and phenolic resin-related parameters, and combine them with the acid gas capture index, lamellar barrier order index, and synergistic stability index to generate the resin interface strengthening index, which is used to comprehensively evaluate the degree of compensation of phenolic resin for coating adhesion and cohesion; compare the resin interface strengthening index with the preset qualified threshold and make production judgment.

2. The method for preparing a polypropylene material treatment-free ink according to claim 1, characterized in that: The acid gas capture index is calculated using the following formula: in: The acid gas capture index; The volume of NaOH consumed after heating the blank CPP sample; The volume of NaOH consumed after heating the barium carbonate sample; For the quality of barium carbonate filler; As the benchmark quality; The effective capture rate of acid; This represents the marginal contribution coefficient of the added amount.

3. The method for preparing a polypropylene material-free ink according to claim 2, characterized in that: After the acid gas capture index is calculated by the formula, it is first compared with the preset first threshold. If the acid gas capture index is greater than or equal to the first threshold, it indicates that the barium carbonate filler has achieved the expected in-situ chemical neutralization ability of hydrogen chloride released from the degradation of chlorinated polypropylene at the given addition amount, and the corresponding filler ratio is qualified. The subsequent measurement steps can be carried out. If the acid gas capture index is lower than the first threshold, it is determined that the current acid capture efficiency of barium carbonate is insufficient. It is necessary to increase the mass fraction of barium carbonate and replace it with a barium carbonate specification with higher activity. The sampling, testing and index calculation of this step should be repeated until the first threshold condition is met.

4. The method for preparing a polypropylene material treatment-free ink according to claim 1, characterized in that: The orderliness index of the sheet barrier is calculated using the following formula: in: The order index of the layer barrier; The half-peak width of the characteristic diffraction peak of mica; Oxygen permeability of the coating; The mass fraction of mica functional filler; To block denser factors; This is the packing adequacy coefficient.

5. The method for preparing a polypropylene material treatment-free ink according to claim 4, characterized in that: The orderliness index of the sheet barrier is compared with a preset second threshold. If the orderliness index of the sheet barrier is greater than or equal to the second threshold, it indicates that the orderliness and density of the sheet barrier network formed by the mica functional filler in the chlorinated polypropylene matrix have reached the expected level, and the corresponding filler ratio and dispersion process are qualified, so subsequent measurements can continue. If the orderliness index of the sheet barrier is lower than the second threshold, it is determined that the orderliness of the current mica sheet orientation and the density of the barrier are insufficient. It is necessary to adjust the mass fraction of mica, improve the grinding and dispersion process, and select a mica variety with a larger aspect ratio. Then, the film preparation, diffraction scanning, air permeability test and sheet barrier orderliness index calculation are repeated until the second threshold condition is met.

6. The method for preparing a polypropylene material treatment-free ink according to claim 1, characterized in that: The cooperative stability index is calculated using the following formula. in: It is a collaborative stability index; Viscosity recovery rate; This is the dispersion stability term; These are the weighting coefficients for the acid gas capture index, the sheet barrier order index, and the dispersion stability term, respectively, satisfying... .

7. The method for preparing a polypropylene material treatment-free ink according to claim 6, characterized in that: The synergistic stability index is compared with a pre-set benchmark threshold range. When the synergistic stability index is within the benchmark threshold range, it is determined that the filler system composed of barium carbonate, mica functional filler, and barium titanate has formed effective synergistic protection in the three dimensions of chemical neutralization, physical barrier, and inert isolation, and the ink base material is allowed to proceed to the subsequent resin interface strengthening step. When the synergistic stability index is lower than the lower limit of the benchmark threshold range, it is determined that the synergistic protection effect of the filler system is insufficient. At this time, the dosage ratio and dispersion process parameters of barium carbonate, mica functional filler, and barium titanate need to be adjusted. After adjustment, the acid gas capture index, the order index of the lamellar barrier, and the viscosity recovery rate are re-measured until the calculated synergistic stability index meets the benchmark threshold range before the subsequent operation can continue.

8. The method for preparing a polypropylene material treatment-free ink according to claim 1, characterized in that: The relevant parameters of the phenolic resin include the mass fraction of phenolic resin added and the density of phenolic resin; the resin interface strengthening index is calculated using the following formula: in: The resin interface strengthening index; It is the adhesion rating of 100 grid lines; Shore hardness; This refers to the gel content; Add mass fraction to phenolic resin; Density of phenolic resin; This is a comprehensive term for interface mechanics; This refers to the crosslinking efficiency term. This is a collaborative benchmark factor.

9. The method for preparing a polypropylene material treatment-free ink according to claim 8, characterized in that: The resin interface strengthening index is compared with a preset qualified threshold. When the resin interface strengthening index is not lower than the preset qualified threshold, it is determined that the filler and resin synergy system of the current batch of polypropylene treatment-free ink has met the requirements for corrosion resistance and heat resistance, and the batch is qualified and allowed to be put into mass production. When the resin interface strengthening index is lower than the preset qualified threshold, it is determined that the current batch of ink has a serious risk of self-corrosion and thermal instability. At this time, the phenolic resin has failed to effectively compensate for the loss of coating adhesion and cohesion caused by the degradation of chlorinated polypropylene. The batch is unqualified and prohibited from being put into production. It is also suggested that the amount of phenolic resin added, the type of phenolic resin, the acid gas capture index, the order index of the layer barrier, and the comprehensive index of synergistic stability should be retrospectively checked and adjusted.

10. A preparation process using the preparation method as described in claim 1, characterized in that, Includes the following steps: Resin dissolution and premixing: An ester solvent is added to a reaction vessel, followed by chlorinated polypropylene resin. The mixture is stirred at low speed until completely dissolved to obtain a resin solution. The resin solution is used for subsequent wetting and dispersion of pigments. High-speed dispersion: Add pigments, dispersants and fillers to the resin liquid and disperse at a high speed of 1000-2000 rpm for 20-30 minutes to initially break up the pigment agglomerates and form a uniform slurry; Fine grinding: The dispersed slurry is ground to a fineness of ≤10μm using a sand mill, with the temperature controlled at ≤50℃, to obtain a uniform and fine ink base material, ensuring the gloss and color strength of the coating film; Formulation optimization and performance verification: Acid gas capture index, sheet barrier order index and synergistic stability index were collected and compared with threshold values ​​to determine the dosage of barium carbonate, mica and barium titanate. Then, phenolic resin is introduced, the resin interface strengthening index is calculated and compared with the qualified threshold to determine whether the formulation is qualified. Filtration, defoaming, and packaging: Qualified ink is allowed to stand to defoam, then filtered through a 200-400 mesh filter to remove impurities, filled and sealed, and labeled with the batch number and performance indicators to obtain the finished polypropylene ink without treatment.

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