Low-silicon release agent for MLCC, preparation method thereof, and release film

Abstract

The present invention discloses a low-silicon release agent for MLCC, a preparation method thereof, and a release film, which includes the following raw material components by mass percentage: 5%-20% modified silicone oil, 10%-40% melamine resin, 0.1%-1% catalyst, 0.2-2% octadecyl isocyanate, and the remainder solvent. The present invention reacts the OH groups on the long chain of the modified silicone oil with the NCO groups, grafts octadecyl isocyanate, and then solidifies the film by the residual OH groups on the long chain of the silicone oil and the melamine resin; under the premise of ensuring a low peeling force, the long-chain alkane improves the wettability of the release agent for the substrate, avoiding the problem of the surface roughness of the release layer surface increasing due to the aggregation of each resin into a protrusion during drying. The release film of the present invention has both the smoothness and peelability of the MLCC release film, and is excellent in weather resistance, with broad market application prospects.

Description

Technical Field

[0001] The present invention relates to the field of MLCC release materials, and in particular to a low-silicon release agent for MLCC, a preparation method thereof, and a release film. Background Art

[0002] MLCCs, due to their small size, high capacitance, and wide operating voltage and temperature ranges, are widely used in automotive electronics, industrial automation, and 5G communications circuits, performing functions such as filtering, coupling, resonance, and bypassing. This presents promising prospects for MLCC domestic production, but also presents significant technical challenges. During the ceramic diaphragm manufacturing process, the MLCC release film directly contacts the ceramic slurry, supporting and stabilizing the release of the ceramic sheet. Therefore, the compatibility, roughness, and cleanliness of the MLCC release film can directly impact the quality of the finished MLCC product. Non-silicone release agents exhibit high peeling force when peeling off ceramic green sheets, damaging thin sheets. Silicone release agents offer low peeling force but relatively low residual strength, resulting in poor substrate wettability and increased roughness of the MLCC release film. Release layers containing binder resins and silicone resins have significantly different solubility in organic solvents and surface tensions of the solvents. This leads to poor compatibility during drying, causing the resins to aggregate into protrusions, which can increase the surface roughness of the release layer. When molding ceramic green sheets with a thickness of 1.0 μm or less, or even 0.6 μm or less, even slight increases in surface roughness can worsen the defect rate of multilayer ceramic capacitors, potentially causing pinholes, etc., and therefore require further smoothness and release properties.

[0003] Patent CN 112280085A discloses a low-roughness, castable MLCC functional release film and its preparation method. The film utilizes a low-temperature-curing silicone oil formulation, enabling the low-temperature-curing release coating to cure at temperatures below 110°C, ensuring thermal shrinkage stability. However, the release layer has a low elastic modulus, making it susceptible to deformation during the peeling process of the ceramic green sheet. This results in low and unstable release force.

[0004] Patent CN 116063886A discloses a high-temperature resistant non-silicone release material, non-silicone release film, and preparation method. By adjusting the ratio of high-molecular-weight acrylic resin to low-molecular-weight acrylic resin, the non-silicone release film exhibits advantages such as excellent high-temperature resistance, low release agent application, low aging creep rate, and high aging residual bonding rate. However, the release force is relatively high, making it difficult to peel the ceramic green sheet from the release layer, which is difficult to meet the low release force requirements of release films for multilayer ceramic capacitors (MLCCs).

[0005] Therefore, it is necessary to improve the existing technology to provide a more reliable solution. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a low-silicon release agent for MLCC, a preparation method thereof and a release film in view of the deficiencies in the above-mentioned prior art.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: in the first aspect of the present invention, a low-silicon release agent for MLCC is provided, comprising the following raw material components by mass percentage: 5%-20% modified silicone oil, 10%-40% melamine resin, 0.1%-1% catalyst, 0.2-2% octadecyl isocyanate and the remainder solvent.

[0008] Preferably, the modified silicone oil is one of polyether-modified hydroxyl-containing silicone oil, polyester-modified hydroxyl-containing silicone oil, and acrylic resin-modified hydroxyl-containing silicone oil.

[0009] Preferably, the molar ratio of -OH in the modified silicone oil to -NCO in octadecyl isocyanate is 2:1 to 4:1.

[0010] Preferably, the molar ratio of -OH in the modified silicone oil to -NCO in octadecyl isocyanate is 2:1 or 3:1 or 4:1.

[0011] Preferably, the catalyst comprises an organotin catalyst and an acidic catalyst.

[0012] Preferably, the organotin catalyst is dibutyltin dilaurate, and the acidic catalyst is p-toluenesulfonic acid.

[0013] Preferably, the solvent is a mixture of butanone, isopropanol and toluene, and in terms of mass percentage of the total raw materials, butanone is 10%-40%, isopropanol is 5%-10%, and toluene is 10%-50%.

[0014] A second aspect of the present invention provides a method for preparing the low-silicon release agent for MLCC as described above, comprising the following steps:

[0015] The modified silicone oil, the organotin catalyst, the octadecyl isocyanate and part of the solvent are mixed and stirred for 15-60 minutes to carry out a prepolymerization reaction so that the -OH in the modified silicone oil reacts completely with the -NCO in the octadecyl isocyanate. Then, the melamine resin, the acidic catalyst and the remaining solvent are added and stirred for 5-30 minutes to obtain the low-silicon release agent for MLCC.

[0016] Preferably, the method for preparing the low-silicon release agent for MLCC comprises the following steps:

[0017] Modified silicone oil, dibutyltin dilaurate, octadecyl isocyanate, and toluene are mixed and stirred for 15-60 minutes to carry out a prepolymerization reaction so that the -OH in the modified silicone oil and the -NCO in the octadecyl isocyanate react completely. Then, melamine resin, acidic catalyst p-toluenesulfonic acid, butanone, and isopropanol are added and stirred for 5-30 minutes to obtain the low-silicon release agent for MLCC.

[0018] The third aspect of the present invention provides a low-silicon release film for MLCC, which is prepared by the following method: uniformly coating the low-silicon release agent for MLCC as described above on a PET film with a thickness of 25-100 μm, controlling the coating thickness to 300-800 nm, and baking at 110-130°C for 0.5-2 min to obtain the low-silicon release film for MLCC.

[0019] The beneficial effects of the present invention are:

[0020] The present invention provides a low-silicon release agent for MLCC, a preparation method thereof, and a release film. The present invention grafts octadecyl isocyanate by reacting the -OH groups on the long chains of modified silicone oil (polyether-modified hydroxyl-containing silicone oil, polyester-modified hydroxyl-containing silicone oil, or acrylic resin-modified hydroxyl-containing silicone oil), and then cures the residual -OH groups on the long chains of the silicone oil with a melamine resin to form a film. While ensuring a low peel force, the long-chain alkane improves the wettability of the release agent to the substrate, avoiding the problem of increased surface roughness of the release layer due to the aggregation of resins into protrusions during drying.

[0021] The melamine resin in the release film structure of the present invention can provide rigidity and curing properties, octadecyl isocyanate can provide flexibility and high wettability, and the modified silicone oil can provide flexibility and low peeling force, so that the release film of the present invention has both the smoothness and peelability of the MLCC release film, and excellent weather resistance, and has broad market application prospects. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below with reference to the embodiments so that those skilled in the art can implement the invention with reference to the description.

[0023] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0024] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Materials and reagents used in the following examples are commercially available unless otherwise specified. In the following examples, where specific conditions are not specified, the experiments were conducted under conventional conditions or those recommended by the manufacturer. Reagents and instruments used, where the manufacturer is not specified, are commercially available conventional products.

[0025] The present invention provides a low-silicon release agent for MLCC, comprising the following raw material components in percentage by mass: 5%-20% of modified silicone oil, 10%-40% of melamine resin, 0.1%-1% of catalyst, 0.2%-2% of octadecyl isocyanate and the remainder of solvent.

[0026] In a preferred embodiment, the modified silicone oil is one of polyether-modified hydroxyl-containing silicone oil, polyester-modified hydroxyl-containing silicone oil, and acrylic resin-modified hydroxyl-containing silicone oil.

[0027] In a preferred embodiment, the molar ratio of -OH in the modified silicone oil to -NCO in octadecyl isocyanate is 2:1 to 4:1. More preferably, the molar ratio of -OH in the modified silicone oil to -NCO in octadecyl isocyanate is 2:1, 3:1, or 4:1.

[0028] In a preferred embodiment, the catalyst comprises an organotin catalyst and an acidic catalyst. Further preferably, the organotin catalyst is dibutyltin dilaurate and the acidic catalyst is p-toluenesulfonic acid.

[0029] In a preferred embodiment, the solvent is a mixture of butanone, isopropanol and toluene, and in terms of mass percentage of the total raw materials, butanone is 10%-40%, isopropanol is 5%-10%, and toluene is 10%-50%.

[0030] The present invention also provides a method for preparing the above low-silicon release agent for MLCC, comprising the following steps:

[0031] Mix modified silicone oil, dibutyltin dilaurate, octadecyl isocyanate, and toluene, stir for 15-60 minutes, and perform a prepolymerization reaction to allow the -OH in the modified silicone oil to react completely with the -NCO in the octadecyl isocyanate. Then add melamine resin, acidic catalyst p-toluenesulfonic acid, butanone, and isopropanol, and stir for 5-30 minutes to obtain a low-silicon release agent for MLCC.

[0032] The present invention also provides a low-silicon release film for MLCC, which is prepared by the following method: uniformly coating the above-mentioned low-silicon release agent for MLCC on a PET film with a thickness of 25-100 μm, controlling the coating thickness to be 300-800 nm, and baking at 110-130° C. for 0.5-2 min to obtain the low-silicon release film for MLCC.

[0033] The above is the overall concept of the present invention. Detailed embodiments and comparative examples are provided below to further illustrate the present invention.

[0034] In the following examples and comparative examples, the acrylic resin-modified hydroxyl-containing silicone oil is BYK3700, BYK Chemical; the polyether-modified hydroxyl-containing silicone oil is BYK377, BYK Chemical; the polyester-modified hydroxyl-containing silicone oil is BYK370, BYK Chemical; and the melamine resin is sourced from CYMEL XW 3106, Allex.

[0035] Example 1

[0036] A method for preparing a low-silicon release agent for MLCC comprises the following steps:

[0037] Accurately weigh 40g of acrylic resin modified hydroxyl silicone oil, 1.6g of octadecyl isocyanate (the molar ratio of -OH in acrylic resin modified hydroxyl silicone oil to -NCO in octadecyl isocyanate is 4:1), 0.02g of dibutyltin dilaurate, and 150g of toluene, mix them, stir them thoroughly for 30min, then add 158.4g of a mixed solvent of butanone and isopropanol (the mass ratio of butanone: isopropanol is 2:1), 50g of melamine resin, and 1g of p-toluenesulfonic acid, stir and disperse for 30min to obtain a low-silicon release agent for MLCC.

[0038] A low-silicon release film for MLCC is prepared by the following method: the low-silicon release agent for MLCC prepared above is evenly coated on a PET film (polyethylene terephthalate) with a thickness of 50 μm, the coating thickness is controlled to be 500 nm, and the film is placed in an oven and baked at 120° C. for 1 min to obtain a low-silicon release film for MLCC.

[0039] Example 2

[0040] A method for preparing a low-silicon release agent for MLCC comprises the following steps:

[0041] Accurately weigh 40g of acrylic resin modified hydroxyl silicone oil, 2.2g of octadecyl isocyanate (the molar ratio of -OH in acrylic resin modified hydroxyl silicone oil to -NCO in octadecyl isocyanate is 3:1), 0.02g of dibutyltin dilaurate, and 150g of toluene, mix them, stir them thoroughly for 30min, then add 157.8g of a mixed solvent of butanone and isopropanol (the mass ratio of butanone: isopropanol is 2:1), 50g of melamine resin, and 1g of p-toluenesulfonic acid, stir and disperse for 30min to obtain a low-silicon release agent for MLCC.

[0042] A low-silicon release film for MLCC is prepared by the following method: the low-silicon release agent for MLCC prepared above is evenly coated on a PET film (polyethylene terephthalate) with a thickness of 50 μm, the coating thickness is controlled to be 500 nm, and the film is placed in an oven and baked at 120° C. for 1 min to obtain a low-silicon release film for MLCC.

[0043] Example 3

[0044] A method for preparing a low-silicon release agent for MLCC comprises the following steps:

[0045] Accurately weigh 40g of acrylic resin modified hydroxyl silicone oil, 3.2g of octadecyl isocyanate (the molar ratio of -OH in acrylic resin modified hydroxyl silicone oil to -NCO in octadecyl isocyanate is 2:1), 0.02g of dibutyltin dilaurate, and 150g of toluene, mix them, stir them thoroughly for 30min, then add 160g of a mixed solvent of butanone and isopropanol (the mass ratio of butanone: isopropanol is 2:1), 50g of melamine resin, and 1g of p-toluenesulfonic acid, stir and disperse for 30min to obtain a low-silicon release agent for MLCC.

[0046] A low-silicon release film for MLCC is prepared by the following method: the low-silicon release agent for MLCC prepared above is evenly coated on a PET film (polyethylene terephthalate) with a thickness of 50 μm, the coating thickness is controlled to be 500 nm, and the film is placed in an oven and baked at 120° C. for 1 min to obtain a low-silicon release film for MLCC.

[0047] Example 4

[0048] A method for preparing a low-silicon release agent for MLCC comprises the following steps:

[0049] Accurately weigh 40g of polyether-modified hydroxyl silicone oil, 2.4g of octadecyl isocyanate (the molar ratio of -OH in acrylic resin-modified hydroxyl silicone oil to -NCO in octadecyl isocyanate is 4:1), 0.02g of dibutyltin dilaurate, and 150g of toluene, mix them, stir them thoroughly for 30min, then add 157.6g of a mixed solvent of butanone and isopropanol (the mass ratio of butanone: isopropanol is 2:1), 50g of melamine resin, and 1g of p-toluenesulfonic acid, stir and disperse for 30min to obtain a low-silicon release agent for MLCC.

[0050] A low-silicon release film for MLCC is prepared by the following method: the low-silicon release agent for MLCC prepared above is evenly coated on a PET film (polyethylene terephthalate) with a thickness of 50 μm, the coating thickness is controlled to be 500 nm, and the film is placed in an oven and baked at 120° C. for 1 min to obtain a low-silicon release film for MLCC.

[0051] Comparative Example 1

[0052] A method for preparing a low-silicon release agent for MLCC comprises the following steps:

[0053] Accurately weigh 40g of acrylic resin modified hydroxyl silicone oil and 150g of toluene, mix them, stir them thoroughly for 30 minutes, then add 160g of a mixed solvent of butanone and isopropyl alcohol (the mass ratio of butanone: isopropyl alcohol is 2:1), 50g of melamine resin, and 1g of p-toluenesulfonic acid, stir and disperse for 30 minutes to obtain a low-silicon release agent for MLCC.

[0054] A low-silicon release film for MLCC is prepared by the following method: the low-silicon release agent for MLCC prepared above is evenly coated on a PET film (polyethylene terephthalate) with a thickness of 50 μm, the coating thickness is controlled to be 500 nm, and the film is placed in an oven and baked at 120° C. for 1 min to obtain a low-silicon release film for MLCC.

[0055] Comparative Example 2

[0056] A method for preparing a low-silicon release agent for MLCC comprises the following steps:

[0057] Accurately weigh 40g of polyether-modified hydroxyl-containing silicone oil and 150g of toluene, mix them, stir them thoroughly for 30 minutes, then add 160g of a mixed solvent of butanone and isopropyl alcohol (the mass ratio of butanone: isopropyl alcohol is 2:1), 50g of melamine resin, and 1g of p-toluenesulfonic acid, stir and disperse for 30 minutes to obtain a low-silicon release agent for MLCC.

[0058] A low-silicon release film for MLCC is prepared by the following method: the low-silicon release agent for MLCC prepared above is evenly coated on a PET film (polyethylene terephthalate) with a thickness of 50 μm, the coating thickness is controlled to be 500 nm, and the film is placed in an oven and baked at 120° C. for 1 min to obtain a low-silicon release film for MLCC.

[0059] Comparative Example 3

[0060] A method for preparing a low-silicon release agent for MLCC comprises the following steps:

[0061] Accurately weigh 40g of polyester-modified hydroxyl silicone oil and 150g of toluene, mix them, stir them thoroughly for 30 minutes, then add 160g of a mixed solvent of butanone and isopropyl alcohol (the mass ratio of butanone: isopropyl alcohol is 2:1), 50g of melamine resin, and 1g of p-toluenesulfonic acid, stir and disperse for 30 minutes to obtain a low-silicon release agent for MLCC.

[0062] A low-silicon release film for MLCC is prepared by the following method: the low-silicon release agent for MLCC prepared above is evenly coated on a PET film (polyethylene terephthalate) with a thickness of 50 μm, the coating thickness is controlled to be 500 nm, and the film is placed in an oven and baked at 120° C. for 1 min to obtain a low-silicon release film for MLCC.

[0063] The following performance tests were performed on the low-silicon release films for MLCC prepared in Examples 1-4 and Comparative Examples 1-3:

[0064] (1) Release film roughness measurement: The roughness of the release film was measured using a white light interferometer. The average roughness of the area surface (Sa) was the average value of 5 measurements. The maximum protrusion height (Rp) was the maximum value of 5 measurements excluding the maximum and minimum values.

[0065] (2) Peel force measurement:

[0066] Preparation of ceramic green sheets: 38.3 g of toluene, 38.3 g of ethanol, 64.8 g of barium titanate, 6.5 g of polyvinyl butyral, and 3.3 g of dioctyl phthalate were weighed, stirred and mixed, and dispersed in a ball mill using 0.5 mm diameter glass beads as a dispersion medium for 60 minutes to obtain a ceramic slurry.

[0067] Use an applicator to apply ceramic slurry to the release surface of the obtained release film sample to a thickness of 10 microns, and dry it at 90°C for 1 minute to form a ceramic green sheet. After eliminating the charge of the obtained release film with ceramic green sheet, cut it into 30 mm wide strips, peel it at a peeling angle of 90 degrees and a peeling speed of 10 m / min, and measure the peeling force.

[0068] The test results are shown in Table 1 below:

[0069] Table 1

[0070] Peel force (mN / mm2) Sa(nm) Rp(nm) Example 1 1.5 0.9 39 Example 2 1.6 0.9 36 Example 3 1.6 0.8 37 Example 4 1.5 0.9 36 Example 5 1.5 0.9 36 Comparative Example 1 1.5 1.8 64 Comparative Example 2 1.6 2.0 59 Comparative Example 3 1.5 2.3 46

[0071] It can be seen from the test data of Examples 1-4 and Comparative Examples 1-3 that, compared with the comparative examples, in Examples 1-4, by grafting octadecyl isocyanate onto the long-chain -OH of modified silicone oil (polyether-modified hydroxyl-containing silicone oil, polyester-modified hydroxyl-containing silicone oil, acrylic resin-modified hydroxyl-containing silicone oil), the roughness of the ceramic film can be greatly reduced while maintaining a low peel force. This is mainly due to the fact that the long-chain alkane improves the wettability of the release agent to the substrate.

[0072] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A low-silicon release agent for MLCC, characterized in that: The invention comprises the following raw material components by mass percentage: 5%-20% of modified silicone oil, 10%-40% of melamine resin, 0.1%-1% of catalyst, 0.2%-2% of octadecyl isocyanate and the balance of solvent; The modified silicone oil is one of polyether-modified hydroxyl-containing silicone oil, polyester-modified hydroxyl-containing silicone oil, and acrylic resin-modified hydroxyl-containing silicone oil; The molar ratio of -OH in the modified silicone oil to -NCO in octadecyl isocyanate is 2:1 to 4:1; The catalyst includes an organic tin catalyst and an acidic catalyst; The method for preparing the low-silicon release agent for MLCC comprises the following steps: The modified silicone oil, the organotin catalyst, the octadecyl isocyanate and part of the solvent are mixed and stirred for 15-60 minutes to carry out a prepolymerization reaction so that the -OH in the modified silicone oil reacts completely with the -NCO in the octadecyl isocyanate. Then, the melamine resin, the acidic catalyst and the remaining solvent are added and stirred for 5-30 minutes to obtain the low-silicon release agent for MLCC.

2. The low-silicon release agent for MLCC according to claim 1, characterized in that The molar ratio of -OH in the modified silicone oil to -NCO in octadecyl isocyanate is 2:1 or 3:1 or 4:

1.

3. The low-silicon release agent for MLCC according to claim 2, characterized in that The organic tin catalyst is dibutyltin dilaurate, and the acidic catalyst is p-toluenesulfonic acid.

4. The low-silicon release agent for MLCC according to claim 3, characterized in that The following steps are involved: The modified silicone oil, the organic tin catalyst dibutyltin dilaurate, octadecyl isocyanate, and toluene are mixed and stirred for 15-60 minutes to carry out a prepolymerization reaction so that the -OH in the modified silicone oil and the -NCO in the octadecyl isocyanate react completely. Then, melamine resin, acidic catalyst p-toluenesulfonic acid, butanone, and isopropanol are added and stirred for 5-30 minutes to obtain the low-silicon release agent for MLCC.

5. A low-silicon release film for MLCC, characterized in that: It is prepared by the following method: the low-silicon release agent for MLCC described in any one of claims 1 to 4 is evenly coated on a PET film with a thickness of 25-100 μm, the coating thickness is controlled to be 300-800 nm, and baked at 110-130° C. for 0.5-2 min to obtain the low-silicon release film for MLCC.