Improvement of adhesion between base material and elastic material layer

Abstract

An embodiment relates to improving adhesion between a base substrate and an elastic material layer. Plasma enhanced chemical vapor deposition (PECVD) is performed to deposit a silicide layer on the base substrate. An elastic material layer is formed on the surface of the silicide layer. An object formed by the method can include a base substrate, a silicide layer on the base substrate, and an elastic material layer on the surface of the silicide layer. By having the silicide layer with a certain surface roughness and thickness, the adhesion between the base substrate and the elastic material layer can be significantly improved.

Description

[Technical Field] 【0001】 Cross-reference of related applications This application claims the benefit of U.S. Utility Patent Application No. 17 / 718,674, filed on 12 April 2022, which is incorporated in its entirety by reference. 【0002】 This disclosure relates to a silicon compound layer that improves adhesion between a base substrate and an elastic material layer. [Background technology] 【0003】 Objects having a base substrate bonded to an elastic material layer are highly useful and widely used in a variety of applications. The base substrate can be made of glass, metal, plastic, etc. In particular, objects having a base substrate bonded to a silicone rubber layer as an elastic material can be used, for example, in household goods, automotive parts, and electronic components, baby bottles, goggles, and bathroom products that require heat resistance and / or transparency and chemical safety. [Overview of the Initiative] [Problems that the invention aims to solve] 【0004】 Typically, elastic materials are bonded to a base material by enhancing the adhesive properties of the silicone rubber layer, applying a primer to the surface of the base material, and then attaching the cured silicone rubber to the base material using an adhesive. However, enhancing the adhesive properties of the silicone rubber layer is often achieved by adding highly reactive materials (e.g., carbon functional silanes) that result in insufficient heat resistance and deformation of the material. Moreover, reactive materials may also adhere to the mold itself during injection molding, making it difficult to control the quality of the molding process. 【0005】 In addition, applying a primer to the surface of the base substrate involves a complex process of applying, drying, and baking the primer, and defects can occur due to uneven application of the primer. Other methods exist to improve the adhesive properties of the base substrate (e.g., UV irradiation, plasma treatment, and corona treatment), but these methods often do not sufficiently improve the adhesive properties to the base material and require hazardous working environments and expensive equipment. Moreover, bonding a silicone rubber layer to the base material using an adhesive can also be difficult, as adhesives usually have insufficient heat resistance or durability, which can be compromised during the manufacturing process. [Means for solving the problem] 【0006】 This embodiment relates to a manufactured product comprising a base substrate, a silicon compound layer on the base substrate, and an elastic material layer on the surface of the silicon compound layer. The silicon compound layer has a surface roughness of 50 nm to 600 nm in Ra units. 【0007】 In one or more embodiments, the thickness of the silicon compound layer is less than 1000 nm but greater than 50 nm. 【0008】 In one or more embodiments, the silicon compound layer is SiO x C y H z It is a layer. 【0009】 In one or more embodiments, SiO x C y H z The layer contains 28-30 wt% silicon, 60-65 wt% oxygen, 0-1 wt% carbon, and 6-9 wt% hydrogen. 【0010】 In one or more embodiments, the base substrate includes at least one of a thermoplastic polymer, a thermosetting polymer, silicone rubber, a metal, and glass. 【0011】 In one or more embodiments, the thermoplastic polymer is at least one of polypropylene (PP), polyester sulfone (PES), polyphenyl sulfone (PPSU), polyamide (PA), Tritan, polycarbonate (PC), and nylon. 【0012】 In one or more embodiments, the elastic material layer is a material selected from the group consisting of liquid silicone rubber (LSR), heat-cured rubber (HCR) silicone, and combinations thereof. 【0013】 In one or more embodiments, the base substrate is PPSU and the elastic material layer is silicone rubber. 【0014】 In one or more embodiments, the silicon compound layer is formed on the base substrate using plasma-enhanced chemical vapor deposition (PECVD). 【0015】 In one or more embodiments, PECVD is performed by reacting the precursor hexamethyldisiloxane (HMDSO) with the reactive gas oxygen (O2) under plasma. 【0016】 The embodiments also relate to a method of manufacturing a manufactured product. Plasma-enhanced chemical vapor deposition (PECVD) is performed to form a silicon compound layer on the base substrate of the manufactured product. An elastic material layer is formed on the surface of the silicon compound layer. 【0017】 In one or more embodiments, the thickness of the silicon compound layer is less than 1000 nm but greater than 50 nm. 【0018】 In one or more embodiments, the surface roughness of the silicon compound layer is 50 nm to 600 nm in Ra units. 【0019】 In one or more embodiments, the silicon compound layer is a SiO x C y H z layer. 【0020】 In one or more embodiments, SiO x C y H z The layer contains 28-30 wt% silicon, 60-65 wt% oxygen, 0-1 wt% carbon, and 6-9 wt% hydrogen. 【0021】 In one or more embodiments, the base substrate includes at least one of a thermoplastic polymer, a thermosetting polymer, silicone rubber, a metal, and glass. 【0022】 In one or more embodiments, the thermoplastic polymer is at least one of polypropylene (PP), polyester sulfone (PES), polyphenyl sulfone (PPSU), polyamide (PA), Tritan, polycarbonate (PC), and nylon. 【0023】 In one or more embodiments, the elastic material layer is a material selected from the group consisting of liquid silicone rubber (LSR), thermosetting rubber (HCR) silicone, and combinations thereof. 【0024】 In one or more embodiments, the base material is PPSU and the elastic material layer is silicone rubber. 【0025】 In one or more embodiments, performing PECVD involves reacting a precursor hexamethyldisiloxane (HMDSO) with a reactive gas oxygen (O2) under plasma conditions. 【0026】 In one or more embodiments, forming an elastic material layer involves injecting a liquid elastic material into a mold containing a base substrate on which the elastic material layer is to be formed. [Brief explanation of the drawing] 【0027】 [Figure 1] This is a flowchart illustrating a method for bonding an elastic material layer to a base substrate according to one embodiment. [Figure 2]The structure of a base substrate, a silicon compound layer, and an elastic material layer according to one embodiment is shown. [Figure 3] This is a schematic diagram showing a cross-sectional view taken across the surface of a polymer material substrate in which a silicon compound layer has not been formed, relating to a comparative example. [Figure 4A] These are cross-sectional views taken across the surface of a polymeric material substrate having a silicon compound layer with a thickness and roughness below a threshold level, according to several embodiments. [Figure 4B] These are cross-sectional views taken across the surface of a polymeric material substrate having a silicon compound layer with a thickness and roughness below a threshold level, according to several embodiments. [Figure 4C] These are cross-sectional views taken across the surface of a polymeric material substrate having a silicon compound layer with a thickness and roughness below a threshold level, according to several embodiments. [Figure 5A] These are cross-sectional views taken across the surface of a polymeric material substrate having a silicon compound layer having a thickness below a threshold and a roughness within a threshold range, according to several embodiments. [Figure 5B] These are cross-sectional views taken across the surface of a polymeric material substrate having a silicon compound layer having a thickness below a threshold and a roughness within a threshold range, according to several embodiments. [Figure 5C] These are cross-sectional views taken across the surface of a polymeric material substrate having a silicon compound layer having a thickness below a threshold and a roughness within a threshold range, according to several embodiments. [Figure 6] This is a cross-sectional view taken across the surface of a polymeric material substrate having a silicon compound layer having a thickness exceeding a threshold and a roughness within a threshold range, according to one embodiment. [Figure 7] This is a cross-sectional view taken across the surface of a polymeric material substrate having a silicon compound layer having a thickness below a threshold and a roughness above a threshold range, according to one embodiment. [Modes for carrying out the invention] 【0028】 Embodiments are described below with reference to the attached drawings. However, the principles disclosed herein can be embodied in many different forms and should not be construed as being limited to the embodiments described herein. In this description, well-known features and technical details may be omitted to avoid unnecessarily obscuring the features of the embodiments. In the drawings, similar reference figures mean similar elements. Shapes, sizes, and areas of the drawings may be exaggerated for clarity. 【0029】 The embodiments relate to articles having a base substrate bonded to an elastic material layer and methods for manufacturing such articles. A silicon compound layer with a predefined surface roughness is deposited on the base substrate, and an elastic material layer is placed on the silicon compound layer to enhance adhesion between the base substrate and the elastic material layer. A silicon compound layer with an average thickness of less than 1000 nm and a surface roughness of 50 nm to 600 nm in Ra units can be deposited using a plasma-accelerated chemical vapor deposition (PECVD) method. Such articles can be used as highly heat-resistant components (e.g., automotive and electronic components) or transparent and chemically safe components (e.g., baby bottles, goggles, and bathroom products). 【0030】 Method for bonding an elastic material layer to a base substrate. Figure 1 is a flowchart illustrating a method for bonding an elastic material layer to a base substrate according to one embodiment. The following embodiments are described with reference to the use of a silicone rubber layer as the elastic material layer, but are not limited thereto, and various materials can be used as the elastic material layer. 【0031】 First, in step 102, a base material is prepared for the object. The base material can be formed from at least one of the following: thermoplastic polymers, thermosetting polymers, silicone rubber, metals such as stainless steel, aluminum, gold, silver, copper, iron, inorganic materials such as aluminum oxide, titanium oxide, and glass. In particular, when the base material contains a thermoplastic polymer, the base material can be formed from at least one of the following: polypropylene (PP), polyester sulfone (PES), polyphenylsulfone (PPSU), polyamide (PA), Tritan, polycarbonate (PC), and nylon. These thermoplastic polymers have high heat resistance and impact resistance. Therefore, base materials containing thermoplastic polymers can be advantageous for applications such as medical devices, baby products, and kitchen products that require repeated disinfection with high temperatures and steam. 【0032】 Next, a film formation method is performed in 104 to deposit a silicon compound layer on the base substrate. The silicon compound layer is mainly silicon dioxide (SiO₂). x C y H z It could be a layer of SiO. x C y H z The layer has an average thickness of less than 1000 nm and a surface roughness of 50 nm to 600 nm in Ra units. Ra represents the arithmetic mean of the absolute values ​​of the cross-sectional height deviation from the average line on the surface of the layer. SiO is effective for bonding silicone to the base substrate. x C y H z The range of surface roughness and thickness was determined based on experiments described in detail below, with reference to Figures 3 to 7. 【0033】 Silicon compound layer (e.g., SiO x C y H zThe surface roughness of the layer is, for example, entirely incorporated here by reference: Ichiko Misuzu et al., “Profile Surface Roughness Measurement Using Metrological Atomic Force Microscope and Uncertainty Evaluation,”11 th The surface roughness can be measured using atomic force microscopy (AFM) as described in Laser Metrology for Precision Measurement and Inspection in Industry 2014 (September 2-5, 2014). Refer to Figures 3-7; the surface roughness in the examples described below was measured using the same method. 【0034】 Silicon compound layer (e.g., SiO x C y H z The thickness of the silicon compound layer can be determined by analyzing scanning electron microscope (SEM) images. First, the surface of a substrate containing or not containing a silicon compound is pre-treated with a platinum coating to prevent any damage to the silicon compound layer. Next, the pre-treated surface is treated with a focused ion beam (FIB). Then, a cross-sectional view of the FIB-treated surface is taken using an SEM. The pixels of the acquired image are then analyzed at multiple points in the image to determine the thickness. The average thickness at multiple points is taken as the thickness of the silicon compound layer. 【0035】 In one embodiment, a silicon compound layer having surface roughness is achieved by depositing the silicon compound layer using plasma-accelerated chemical vapor deposition (PECVD). As an example, the PECVD process may be carried out under relatively low temperature and low pressure conditions to obtain the desired surface roughness of the silicon compound layer on the base substrate. The pressure of the PECVD process is 1 × 10⁻⁶ -2The temperature can be ~1 Torr, and the temperature of the base substrate during at least part or all of the PECVD process can be 50°C to 200°C. Si-containing precursor gases and reactive gases can be used in the PECVD process. The Si-containing precursor is hexamethyldisiloxane (HMDSO), and the reactive gas is oxygen (O2). 【0036】 The silicon compound layer formed by this PECVD process is SiO x C y H z It can be a layer. In one or more embodiments, the ratios of silicon, oxygen, carbon, and hydrogen are in the range of 28-30 wt%, 60-65 wt%, 0-1 wt%, and 6-9 wt%, respectively. The composition of the silicon compound layer can be determined, for example, using Rutherford Backscattering Spectrometry (RBS) Elastic Recoil Detection (ERD) as is well known in the art. 【0037】 Returning to Figure 1, at 106, an elastic material layer is formed on the surface of the silicon compound layer. In particular, the elastic material layer can be formed by applying an elastic material to the surface of a silicon compound layer having a surface roughness within a threshold range. The effect is to improve the adhesion between the base substrate and the resulting elastic material layer. The elastic material may be LSR, HCR, or a combination thereof. 【0038】 In one embodiment, the elastic material is applied to the base substrate having the silicon compound layer by placing or fixing an object comprising a base substrate and a silicon compound layer in the mold of an injection molding machine, filling the mold of the injection molding machine with the elastic material, and attaching the elastic material to the surface of the silicon compound layer. 【0039】 In one embodiment, plasma treatment is performed on the surface of the base substrate before the silicon compound layer is deposited. Plasma treatment reduces contaminants or other particles on the base substrate, resulting in improved adhesion between the base substrate and the silicon compound layer to be deposited. 【0040】 Furthermore, an ionization process may be performed on the surface of the silicon compound layer before forming the elastic material layer. While the relatively high surface roughness of the silicon compound layer improves physical and mechanical adhesion with the elastic material layer, performing an ionization process can further improve adhesion by increasing the surface energy of the silicon compound layer. 【0041】 composite structure Figure 2 shows a composite structure 100 comprising a base substrate 110, a silicon compound layer 130, and an elastic material layer 120 according to one embodiment. The following composite structure 100 may form part or all of an article and may be obtained by performing the steps described in detail in relation to Figure 1. 【0042】 The base substrate 110 forms the base material for the composite structure 100 and may be formed from the materials and properties described in relation to step 102 of the method shown in Figure 1. The elastic material layer 120 provides texture and impact resistance to the object formed in the composite structure 100 and may be formed from the materials and properties described in relation to the formation of the elastic material layer 106 described above in relation to Figure 1. 【0043】 The silicon compound layer 130 is formed between the base substrate 110 and the elastic material layer 120, and is formed from the materials and properties described in relation to step 104 of the method shown in Figure 1. In particular, the surface of the silicon compound layer 130 in contact with the elastic material layer 120 has a surface roughness within a threshold range, which can improve the bonding of the elastic material layer 120 to the base substrate 110. The silicon compound layer 130 may also have an average thickness below a threshold. In one example, the base substrate 110 may be made of PPSU, the elastic material layer 120 may be made of silicone rubber, while the silicon compound layer 130 may have a surface roughness between 50 nm and 600 nm and an average thickness of less than 1000 nm but greater than 50 nm. 【0044】 Experimental results In the following embodiment, SiO x C y H z The adhesion of silicone to a PPSU baby bottle container was tested using a layer. In the example, an ionization procedure was performed to activate the surface of the PPSU, followed by SiO x C y H z To form the layer, a PECVD process was used that requires HMDSO as a Si-containing precursor and O2 as a reactive gas. Then, SiO x C y H z After a PPSU substrate in the form of a baby bottle with layers is placed in the mold of an injection molding machine, the mold is filled with LSR silicone. Then, the PPSU substrate coated with LSR silicone is cooled to cure the silicone. x C y H z After attaching the silicone to the PPSU via a layer, the baby bottle was immersed in boiling water at a pressure of 2 atmospheres for a predetermined time to determine whether the adhesion between the PPSU and the silicone was maintained. Separately, an adhesive was used to attach the silicone to the PPSU substrate. x C y H z It was never placed between the layer and the silicone. 【0045】 Figure 3 shows the SiO2 in relation to the comparative example. x C y H z This is a scanning electron microscope (SEM) image of a cross-sectional view taken across the surface of a PPSU substrate without a film deposition and across the silicone. Therefore, SiO x C y H z The layer thickness was zero, and the roughness of the PPSU substrate was less than 5 nm (Ra). x C y H z In the absence of a layer, the silicone separated from the PPSU even before being immersed in boiling water. 【0046】 Figures 4A to 4C show SiO2 with a roughness below the threshold level according to several embodiments. x C y H z This is an SEM image of a cross-section taken across the surface of a PPSU substrate with layers. x C y H z The layer roughness was lower than 50 nm (Ra). Figure 4A shows SiO x C y H z The average thickness of the layer is 42.8 nm, SiO x C y H z Figure 4B shows an SEM image of a PPSU substrate with a layer roughness of 0.26 nm (Ra). x C y H z The layer thickness is 197 nm, SiO x C y H z This is an SEM image of a PPSU substrate with a layer roughness of 11.15 nm (Ra). In this example, the final thickness of SiO x C y H z Three separate cycles of PECVD were performed to obtain the layer. Figure 4C shows SiO x C y H z The layer thickness is 721 nm, SiO x C y H zSEM image of a PPSU substrate with a layer roughness of 25.64 nm (Ra). In the examples of FIGS. 4A to 4C, the silicone initially adhered to the PPSU substrate, but then the substrate and the silicone separated when immersed in boiling water for 30 hours. Therefore, these examples show that SiO x C y H z When the roughness of the layer was lower than 50 nm (Ra), SiO x C y H z Even when the layer thickness was less than 1000 nm, it indicated that the silicone was not properly attached to the substrate. 【0047】 FIGS. 5A to 5C are SEM images of cross-sectional views taken across the surface of a PPSU substrate having a SiO x C y H z layer within a predetermined range. That is, the roughness of the SiO x C y H z layer was 50 nm (Ra) or more but less than 600 nm (Ra). FIG. 5A shows that the average thickness of the SiO x C y H z layer was 127.3 nm, and the SEM image of the PPSU substrate with the SiO x C y H z layer having a roughness of 56.85 nm (Ra). FIG. 5B shows that the average thickness of the SiO x C y H z layer was 263.1 nm, and the SEM image of the PPSU substrate with the SiO x C y H z layer having a roughness of 203.4 nm (Ra). FIG. 5C shows that the average thickness of the SiO x C y H z layer was 400.7 nm, and the SEM image of the PPSU substrate with the SiO x C y H zThis is an SEM image of a PPSU substrate with a layer roughness of 454 nm (Ra). In the examples shown in Figures 5A to 5C, the silicone was attached to the PPSU substrate and remained attached to the substrate even after the substrate and silicone were immersed in boiling water for 50 hours. Therefore, these examples show that SiO x C y H z The layer roughness is within a threshold range of 50 nm (Ra) to 600 nm (Ra), and SiO x C y H z If the average thickness of the layer is less than 1000 nm, it indicates that the silicone has been properly attached to the substrate. 【0048】 Figure 6 shows several embodiments of SiO x C y H z The layer roughness is within the threshold range, but SiO x C y H z This is an SEM image of a cross-section taken across the surface of a PPSU substrate where the average layer thickness exceeds a threshold level. In particular, SiO x C y H z The average thickness of the layer is 1,207.9 nm, and SiO x C y H z The layer roughness was 224.1 nm (Ra). In this example, the silicone was initially attached to a PPSU substrate, but was separated from the substrate after being immersed in boiling water for 30 hours. This example uses SiO x C y H z This indicates that if the layer thickness is greater than 1000 nm, the silicone cannot be properly attached to the substrate. 【0049】 Figure 7 is a cross-sectional view taken across the surface of a PPSU substrate having a silicon compound layer with a thickness below a threshold level and a roughness above a threshold range, according to one embodiment. In the example of Figure 7, SiO x C y H z The layer thickness is 256.6 nm, and SiO x Cy H z The layer roughness was 732 nm (Ra). In this example, the silicone was initially attached to a PPSU substrate but was separated from the substrate after immersion in boiling water for 30 hours. This example uses SiO x C y H z When the layer roughness exceeds 600 nm (Ra), SiO x C y H z This indicates that silicone cannot be properly attached to the substrate even if the layer thickness is less than 1000 nm. 【0050】 The experiment was also conducted using materials other than PPSU as the base substrate. Specifically, a lap shear test was performed using two specimens according to ASTM D1002, with a silicon compound layer (e.g., SiOxCyHz layer) deposited on each specimen. Then, LSR was applied to the silicon compound layer-deposited surface of one specimen. Next, the other specimen was placed on top of the silicon compound layer-deposited surface facing the LSR-coated surface. The specimens were pressed together until the LSR reached a predetermined thickness (e.g., 1 mm), and then baked to cure the LSR into silicone. The two specimens were then pulled in opposite directions to test the fracture shear force at the overlapping portion of the specimens. 【0051】 For various test specimen materials (e.g., polycarbonate, glass, polypropylene, and stainless steel), the maximum pre-fracture shear force was measured to test the applicability of silicon compounds to these materials. The SiOxCyHz layer was deposited under PECVD conditions similar to those in the examples in Figures 5A-5C, and is therefore estimated to have a thickness of less than 1000 nm and a roughness in the range of 50 nm (Ra) to 600 nm (Ra). The lap shear test was performed three times for each material, with and without the SiOxCyHz layer, and the average maximum shear force was compared. The results are as follows: [Table 1] 【0052】 As shown in Table 1, a significant increase in maximum shear force was observed when the SiOxCyHz layer was deposited on the sample material. In the case of stainless steel, the increase in shear force due to the deposition of the SiOxCyHz layer was approximately 691 times. Only PPSU, polycarbonate, glass, polypropylene, and stainless steel were used as the basis substrate material, but similar results can be expected with other materials. 【0053】 While this disclosure has been described above in relation to several embodiments, various modifications can be made within the scope of the disclosure. Therefore, the disclosure described above is intended to be illustrative but not limiting.

Claims

[Claim 1] Base material and A silicon compound layer on the base substrate, the silicon compound layer having an outer surface having a surface roughness of 50 nm to 600 nm in Ra units, A silicone rubber layer is provided directly on the outer surface of the silicon compound layer, Equipped with, The base material is polyphenylsulfone (PPSU), The thickness of the silicon compound layer is less than 1000 nm but greater than 50 nm. A manufactured product wherein the silicon compound layer contains silicon, oxygen, carbon, and hydrogen. [Claim 2] The manufactured product according to claim 1, wherein the silicon compound layer comprises 28 to 30 wt% silicon, 60 to 65 wt% oxygen, 0 to 1 wt% carbon, and 6 to 9 wt% hydrogen. [Claim 3] The article according to claim 1, wherein the silicone rubber layer is made of a material selected from the group consisting of liquid silicone rubber (LSR), thermosetting silicone rubber (HCR), and combinations thereof. [Claim 4] Plasma-accelerated chemical vapor deposition (PECVD) is used to deposit a silicon compound layer on a base substrate of a manufactured product, wherein the outer surface of the silicon compound layer has a surface roughness of 50 nm to 600 nm in Ra units. A silicone rubber layer is directly formed on the outer surface of the silicon compound layer. Includes, The base material is polyphenylsulfone (PPSU), The thickness of the silicon compound layer is less than 1000 nm but greater than 50 nm. A method wherein the silicon compound layer comprises silicon, oxygen, carbon, and hydrogen. [Claim 5] The method according to claim 4, wherein the silicon compound layer comprises 28 to 30 wt% silicon, 60 to 65 wt% oxygen, 0 to 1 wt% carbon, and 6 to 9 wt% hydrogen. [Claim 6] The method according to claim 4, wherein the silicone rubber layer is a material selected from the group consisting of liquid silicone rubber (LSR), thermosetting rubber (HCR) silicone, and combinations thereof. [Claim 7] Performing PECVD involves using the precursor hexamethyldisiloxane (HMDSO) as a reactive gas, oxygen (O). ２ The method according to claim 4, comprising reacting with under plasma. [Claim 8] The method according to claim 4, wherein forming the silicone rubber layer includes injecting liquid silicon into a mold containing the base substrate on which the silicone rubber layer is formed.

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