JP6297934B2 - Resin product and method for producing the resin product - Google Patents

Description

  The present invention relates to a resin product and a method for producing the resin product.

  In recent years, many resin products have been used from the viewpoints of weight reduction and cost reduction. Such resin products are used with various functions added depending on the application. Examples of functions added to the resin product include hydrophilicity and hydrophobicity imparted to the surface thereof.

For example, as a method for hydrophilizing the surface of a resin product, a method of forming a SiO ₂ film on the surface of the resin product is known (see, for example, Patent Document 1). In the method of hydrophilizing the surface of the microchip (resin product) described in Patent Document 1, after applying a coating solution mainly composed of SiO ₂ to the surface of the microchip substrate, the solvent of the coating solution is volatilized, A SiO ₂ film is formed on the surface of the microchip substrate. Through the above steps, hydrophilicity can be imparted to the microchip.

International Publication No. 2008/065880

  However, the microchip hydrophilized by the method described in Patent Document 1 has a problem that the hydrophilicity of the microchip substrate surface decreases with time for various reasons.

  Then, the objective of this invention is providing the resin product which can maintain the hydrophilic effect compared with the conventional hydrophilic treatment, and the manufacturing method of the said resin product.

The resin product according to the present invention has a resin member and a SiO ₂ film disposed on the surface of the resin member, and the surface shape of the SiO ₂ film has a degree of distortion exceeding 0, If the arithmetic average roughness is greater than 2 nm, the kurtosis is less than 3.1, the roughness factor is greater than 1.1, and the skewness is 0 or less, the arithmetic average roughness is greater than 10 nm The kurtosis is less than 3.1 and the roughness factor is greater than 1.1.

Method for producing a resin product according to the present invention includes the steps of forming an uneven surface of the resin member, forming a SiO ₂ film on the surface of the resin member which irregularities are formed having the SiO ₂ film When the skewness is greater than 0, the arithmetic mean roughness is greater than 2 nm, the kurtosis is less than 3.1, the roughness factor is greater than 1.1, and the skewness is 0. In the following cases, the arithmetic average roughness is more than 10 nm, the kurtosis is less than 3.1, and the roughness factor is more than 1.1.

  ADVANTAGE OF THE INVENTION According to this invention, the resin product which can maintain a hydrophilic effect compared with the resin product which performed the conventional hydrophilic treatment can be provided.

1A and 1B are graphs showing the relationship between the elapsed days of each resin product and the contact angle. FIGS. 4 is a surface image of the resin product No. 4 and FIG. It is a graph which shows the relationship between the elapsed days of 4 resin products, and a contact angle. FIGS. 11 is a surface image of the resin product No. 11, and FIG. It is a graph which shows the relationship between the elapsed days of 11 resin products, and a contact angle.

  Hereinafter, embodiments of the present invention will be described in detail.

(Composition of resin products)
The resin product according to the present invention has a resin member and a SiO ₂ film. The resin product according to the present invention has a hydrophilic region on at least a part of the surface of the resin member. Then, a SiO ₂ film having a predetermined surface shape to be described later, by forming a region desired to be hydrophilic, and impart excellent hydrophilicity to the surface of the resin member. The resin product may be composed of only a resin member having an SiO ₂ film, or may be a combination of a resin member having an SiO ₂ film and another member (for example, a metal member).

  The shape of the resin member is not particularly limited and can be appropriately designed. For example, the resin member is a microchip having a well or a microchannel chip having a microchannel. The kind of resin constituting the resin member is not particularly limited, and can be appropriately selected from known resins. Examples of the resin constituting the resin member include polymethyl methacrylate, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, vinyl chloride, polypropylene, polyether, polyethylene, polystyrene, silicone resin, and elastomer.

The surface shape of the resin member in the region where the SiO ₂ film is disposed is not particularly limited as long as the surface shape of the SiO ₂ film can be a predetermined uneven shape described later. Here, the “surface shape of the resin member” does not mean a macro shape such as the well or the micro flow path described above, but means the surface roughness (micro shape) of the resin member. For example, the surface shape of the resin member in the region where the SiO ₂ film is disposed has a calculated average roughness of more than 2 nm, a kurtosis of less than 3.1, and a roughness factor of when the skewness is more than 0. It is about 1.1 or more. Further, the surface shape of the resin member in the region where the SiO ₂ film is disposed has a calculated average roughness of more than 10 nm, a kurtosis of less than 3.1, and a roughness factor of when the skewness is 0 or less. It is about 1.1 or more. Incidentally, if it is possible to a predetermined irregular shape which will be described later the surface shape of the SiO ₂ film, the surface shape of the resin member in the area for arranging the SiO ₂ film may be flat.

The SiO ₂ film is disposed at least in a region where hydrophilicity is to be imparted on the surface of the resin member. For example, in the case of a microchip has a resin member mentioned above, the SiO ₂ is disposed on the inner surface of the well, in the case of the micro-channel chip is resin member described above, the inner surface of the SiO ₂ is microchannel and reservoir Is arranged. The material constituting the SiO ₂ film is not particularly limited as long as it contains SiO ₂ as a main component.

A predetermined uneven shape is formed on the surface of the SiO ₂ film. The resin product according to the present embodiment exhibits hydrophilicity when water enters between the irregularities formed on the surface of the SiO ₂ film. Thus, in order for water to enter between the irregularities, the surface shape of the SiO ₂ film has a calculated average roughness of more than 2 nm and a kurtosis of less than 3.1 when the skewness is more than 0. And the roughness factor needs to be greater than 1.1. Alternatively, the surface shape of the SiO ₂ film has a calculated average roughness of more than 10 nm, a kurtosis of less than 3.1, and a roughness factor of more than 1.1 when the skewness is 0 or less. is necessary.

  Skewness (skewness: Rsk) is an index indicating the symmetry of peaks and valleys with respect to the average line in the roughness curve. When the skewness is less than 0, it indicates that the height distribution is biased downward (valley part) with respect to the average line, and when the skewness exceeds 0, the height distribution is the average line. In contrast, when the skewness is 0, the height distribution is symmetric with respect to the average line. The arithmetic average roughness (Ra) is an arithmetic average roughness defined in JIS B 2001, and indicates an average of absolute values of Z (x) (height distribution) in the roughness curve.

Further, the kurtosis (Cultosis: Rku) is an index indicating the sharpness of the height distribution in the roughness curve. When the kurtosis is more than 3.1, it indicates that the height distribution is sharp, and when the kurtosis is less than 3, the height distribution indicates a collapsed shape. Is 3 indicates that the height distribution is a normal distribution. The roughness factor (Rf) indicates the ratio of the actual surface area to the projected area of the SiO ₂ film surface.

  The method for producing the resin product according to the present invention is not particularly limited. For example, the resin product according to the present invention can be manufactured by the method for manufacturing a resin product according to the present invention described below.

(Method for manufacturing resin products)
The method for producing a resin product according to the present invention includes a step of forming irregularities on the surface of the resin member and a step of forming an SiO ₂ film on the surface of the resin member on which the irregularities are formed.

  First, a resin member is prepared. The resin member may be manufactured or purchased. For example, the resin member may be molded by the injection molding method using the above-described resin, or may be manufactured by cutting.

Then, the region to be hydrophilic on the surface of the resin member, forming irregularities for the surface shape of the SiO ₂ film with a predetermined concave-convex shape. For example, a concavo-convex shape having a skewness of more than 0, an arithmetic average roughness of more than 2 nm, a kurtosis of less than 3.1, and a roughness factor of more than 1.1 is formed. Alternatively, an uneven shape having a skewness of 0 or less, an arithmetic average roughness of more than 10 nm, a kurtosis of less than 3.1, and a roughness factor of more than 1.1 is formed. The method for forming irregularities on the surface of the resin member is not particularly limited. Examples of methods for forming irregularities on the surface of the resin member include plasma treatment, cutting treatment, etching treatment using acid, treatment by pressing a mold having a predetermined irregular shape formed on the surface against the resin member, etc. included. Note that, when the unevenness is formed by the plasma treatment, when oxygen is used as the gas species, the above-described distortion becomes “+ (plus)”. On the other hand, when argon is used as the gas species, the above-described distortion becomes “− (minus)”. Further, when the processing time of the plasma processing is increased, the arithmetic average roughness and roughness factor described above increase and the kurtosis described above decreases.

Finally, a SiO ₂ film is formed so as to cover at least the region where the unevenness is formed (region to be hydrophilized). For example, the SiO ₂ film may be formed by performing ALD, CVD, vapor deposition, or the like. The film thickness of the SiO ₂ film is, for example, about ₂ to 100 nm.

  The resin product which concerns on this invention can be manufactured according to the above process.

(effect)
As described above, in the resin product according to the present embodiment, when the surface shape of the SiO ₂ film has a skewness of more than 0, the arithmetic average roughness is more than 2 nm and the kurtosis is less than 3.1. Yes, when the roughness factor is greater than 1.1 and the skewness is 0 or less, the arithmetic average roughness is greater than 10 nm, the kurtosis is less than 3.1, and the roughness factor is greater than 1.1 . As shown in Examples described later, hydrophilicity could be maintained for a long period of time by forming a predetermined uneven shape on the surface of the SiO ₂ film. In addition, it is estimated that maintaining hydrophilicity for a long period of time as one of the mechanisms exerts its effect when water enters the irregularities on the surface of the SiO ₂ film.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail with reference to an Example, this invention is not limited by these Examples.

  The effects of the above-described skewness, arithmetic average roughness, kurtosis, and roughness factor on the hydrophilicity of resin products were investigated.

1. Production of resin product (1) Plasma treatment An acrylic resin plate was prepared as a resin member. Plasma treatment was performed on one surface of the acrylic resin plate to give an uneven shape to the surface (Nos. 2 to 14). The gas species used for the plasma treatment is oxygen or argon. The gas flow rate was 50 mL / min, and the applied voltage was 100 V. Ra, kurtosis and roughness factor were adjusted by changing the processing time of plasma processing. Moreover, the acrylic resin board which does not perform a plasma process was also prepared (No. 1).

(2) plasma treated surface of the SiO ₂ film forming an acrylic resin plate, to form a SiO ₂ film having a film thickness of 5nm by ALD, No. 1 to 14 resin products were obtained. For each resin product was measured unevenness of the SiO ₂ film surface in an atomic force microscope (AFM). Table 1 shows the conditions of the plasma treatment applied to the 14 types of resin products obtained and the parameters of the uneven shape of the SiO ₂ film.

2. Evaluation of hydrophilicity 1-No. Each of the 14 resin products was evaluated for hydrophilicity. The hydrophilicity is evaluated by dropping water onto the SiO ₂ film after a predetermined period of time has elapsed since the production of the resin product, and static contact between the surface of the SiO ₂ film and water using a contact angle measuring device. This was done by measuring the corners. When the contact angle was 20 ° or less after 30 days from the production of the resin product, the hydrophilicity was judged to be good.

  FIG. 1 is a graph showing the relationship between the elapsed days of each resin product and the contact angle. FIG. 1A is a graph showing the relationship between the elapsed days and the contact angle when the skewness is greater than 0 (when the gas type of the plasma treatment is oxygen), and FIG. It is a graph which shows the relationship between elapsed days and a contact angle in the case where the gas type of a process is argon.

  The solid line of the black circle symbol in FIG. 1 shows the result of the resin product, and the solid line of the white circle symbol is No. 1. 2 shows the result of the resin product. 3 shows the result of the resin product No. 3, the broken line of the white circle symbol is No. 4 shows the result of the resin product No. 4, and the one-dot chain line of the black circle symbol is 5 shows the result of the resin product No. 5, and the one-dot chain line of the white circle symbol is The result of 6 resin products is shown. The solid line of the white circle symbol in FIG. 7 shows the result of the resin product No. 7, the broken line of the black circle symbol is No. 8 shows the result of the resin product, and the broken line of the white circle symbol is No. 8. The results of the resin product No. 9 are shown. 10 shows the result of the resin product. 11 shows the result of the resin product, and the solid line of the black triangle symbol is No. 10. 12 shows the result of the resin product, and the solid line of the white triangle symbol is No. The result of 13 resin products is shown. The broken line of the black triangle symbol is No. The result of 14 resin products is shown.

FIGS. 4 is an AFM image of the surface of the SiO ₂ film in resin product No. 4. 2A is a surface image immediately after production, FIG. 2B is a surface image after 30 days have elapsed, and FIG. 2C is a three-dimensional image immediately after production. FIG. It is a graph which shows the relationship between the elapsed days in 4 resin products, and a contact angle. FIGS. 11 is an AFM image of the surface of the SiO ₂ film in 11 resin products. 3A is a surface image immediately after production, FIG. 3B is a surface image after 30 days have elapsed, and FIG. 3C is a three-dimensional image immediately after production. FIG. It is a graph which shows the relationship between the elapsed days in 11 resin products, and a contact angle.

As shown in FIG. Since the resin product No. 1 was not subjected to plasma treatment, and the surface of the SiO ₂ film was not formed with an uneven shape, the contact angle increased with time. That is, no. The hydrophilicity of the resin product 1 decreased with time. The arithmetic average roughness was 2 or less, and the roughness factor was 1.1 or less. The contact angle of the resin product No. 2 also increased with time.

  On the other hand, as shown in FIG. The resin products of 3 to 6 had a skewness of over 0, an arithmetic average roughness of over 2 nm, a kurtosis of less than 3.1, and a roughness factor of over 1.1. The contact angle after 30 days from the preparation was as good as 20 ° or less.

  As shown in FIG. 1B, No. 1 having a kurtosis of 3.1 or more and a roughness factor of 1.1 or less. In the resin products of 7 to 9, the contact angle increased with time. On the other hand, as shown in FIG. 1B and FIG. 3, the skewness is 0 or less, the arithmetic average roughness is more than 10 nm, the kurtosis is less than 3, and the roughness factor is more than 1.1. . 10-No. In 14 resin products, the contact angle after 30 days from the production of the resin product was as good as 20 ° or less.

  The resin product according to the present invention is useful in various apparatuses and devices that require a highly durable hydrophilic function in a plastic material, such as a microchannel chip and a substrate used in the scientific field and the medical field, for example. .

Claims (3)

A resin member;
A SiO ₂ film disposed on the surface of the resin member;
Have
The surface shape of the SiO ₂ film is
If the skewness is greater than 0, the arithmetic average roughness is greater than 2 nm, the kurtosis is less than 3.1, the roughness factor is greater than 1.1,
When the skewness is 0 or less, the arithmetic average roughness is more than 10 nm, the kurtosis is less than 3.1, and the roughness factor is more than 1.1.
Resin products. Forming irregularities on the surface of the resin member;
Forming a SiO ₂ film on the surface of the resin member on which irregularities are formed;
Have
The surface shape of the SiO ₂ film is
If the skewness is greater than 0, the arithmetic average roughness is greater than 2 nm, the kurtosis is less than 3.1, the roughness factor is greater than 1.1,
When the skewness is 0 or less, the arithmetic average roughness is more than 10 nm, the kurtosis is less than 3.1, and the roughness factor is more than 1.1.
Manufacturing method of resin products.   The method for producing a resin product according to claim 2, wherein in the step of forming irregularities on the surface of the resin member, plasma treatment is performed using at least one of oxygen and argon.