JP5461089B2 - Copper foil composite - Google Patents

Description

  The present invention relates to a copper foil composite in which a resin layer is provided on one side of a copper foil or a copper alloy foil, for example, a copper foil composite that can be applied to the surface of an article to impart antibacterial properties.

  It is well known that copper ions in copper or copper alloys have an antibacterial action. In March 2008, the US Environmental Protection Agency (EPA) proved that copper and copper alloys could sterilize pathogens such as methicillin-resistant Staphylococcus aureus (MRSA). Sterilize more than 99.9% of the pathogens tested within 2 hours, and even if the same surface is repeatedly contaminated with this pathogen, it will continue to sterilize 99% "," copper and copper alloys This surface is not meant to eliminate the need for routine infection control measures such as cleaning and disinfection of environmental surfaces, but is considered to complement that measure. Although it has not completely prevented cross-contamination, it has been proven to reduce the risk of pathogen contamination. "

From this, it is apparent that it is desirable from the viewpoint of antibacterial properties to form a portion touched by an unspecified number of people such as a door knob, a handrail or a wall from copper or a copper alloy. However, in reality, copper door knobs are not widely used. This is because copper and copper alloys are expensive compared to materials such as stainless steel and wallpaper that are usually used for door knobs, handrails, walls, etc., copper is discolored, and durability is low. Conceivable.
In view of this, a method has been considered in which a thin copper foil or a composite material obtained by bonding a copper foil to resin, paper, or the like is attached to a door knob, a handrail, a wall, or the like. Furthermore, an attempt has been made to improve design and workability by wrinkling a copper foil. (See Patent Document 1)

JP-A-11-239603

However, in the case of the above-described method of attaching the copper foil, the cut surface is exposed because the copper foil is a thin metal, and the skin may be cut. Therefore, it is necessary to bend the cut surface or cover the cut surface with another material such as a resin.
Further, in the case of the technique described in Patent Document 1, the copper foil is wrinkled or wrinkled in order to improve workability and designability, but in order to maintain wrinkles, the copper foil is thickened. Therefore, it is necessary to ensure strength. Therefore, in the case of this technique, the thickness of the copper foil is set to 10 μm or more and 20 μm or less. However, since the cut property of the cut surface becomes high, it is unsuitable for use with the cut surface exposed.

Furthermore, in order to perform wrinkle processing and skin wrinkle processing, a rolling process or the like is required, resulting in an increase in cost. In addition, when wrinkle processing and skin wrinkle processing are performed, although a certain degree of flexibility is obtained, the strength and elongation remain the same as the original copper foil, and there is a disadvantage that the thinner the copper foil, the easier it is to cut ing. For this reason, a polyethylene film or paper is attached to the back surface of the copper foil as a reinforcing material. However, although it is easy to supplement the strength, it is difficult to increase the elongation of the composite of the copper foil and the film.
Here, annealing is generally performed in order to improve the elongation of the copper foil. However, in the case of foil, the elongation is lower than that of the plate material due to the effect of the thickness. For example, in the case of a normal rolled copper foil, the elongation is less than 10% when the thickness is less than 10 μm, and the elongation is a value of around 5%. It broke and was not practical.

  Accordingly, an object of the present invention is to provide a copper foil composite that has improved cutability while reducing the cutability of the cut surface.

The present inventors can reduce the thickness of the copper foil or copper alloy foil by configuring a composite of the copper foil or copper alloy foil and the resin layer, and further reduce the rigidity of the copper foil or copper alloy foil. It has been found that the cutting ability of the cut surface is lowered by lowering. Furthermore, by balancing the thickness and strength of the copper foil or copper alloy foil and the strength of the resin, the present invention succeeded in increasing the workability, particularly the elongation, as a copper foil composite.
That is, the copper foil composite of the present invention has a copper foil or copper alloy foil and a resin layer provided on one side of the copper foil or copper alloy foil, and the thickness of the copper foil or copper alloy foil is 2 μm or more and less than 10 μm and a tensile strength of 250 MPa or less, and the resin layer is made of polyethylene terephthalate, or a polyethylene terephthalate film, and an adhesive resin layer for bonding the film and the copper foil or copper alloy foil The resin layer has a thickness of 10 μm or more and a tensile strength of 200 MPa or more.

The copper foil composite preferably has a tensile strength of 200 MPa or less and a breaking strain of 20% or more .
The copper foil composite of the present invention is preferably used for antibacterial applications.

  ADVANTAGE OF THE INVENTION According to this invention, the copper foil composite which improved the workability while reducing the cut property of a cut surface can be obtained.

  The copper foil composite of the present invention is formed by providing a resin layer on one side of a copper foil or a copper alloy foil. When the other surface of the copper foil or copper alloy foil is exposed, an antibacterial effect can be imparted by the action of copper ions, but when not used for antibacterial applications, the other surface of the copper foil or copper alloy foil is coated. May be.

<Copper foil or copper alloy foil>
The thickness of the copper foil or copper alloy foil is 2 μm or more and less than 10 μm, and the tensile strength is 250 MPa or less.
If the thickness of the copper foil or copper alloy foil exceeds 10 μm, the strength of the cross section of the copper foil or copper alloy foil becomes too high, and the cut property of the cut surface becomes high.
On the other hand, it is difficult to make the thickness of the copper foil or copper alloy foil less than 2 μm, and it breaks in the middle of the process such as making the composite material by reducing the strength of the copper foil or copper alloy foil. It becomes easy.
Moreover, when the tensile strength of copper foil or copper alloy foil exceeds 250 MPa, even if the copper foil or copper alloy foil is thinned, the tensile strength of the copper foil composite increases and the workability of the copper foil composite decreases. Desirably, the tensile strength of copper foil or copper alloy foil shall be 200 Mpa or less. The lower limit of the tensile strength of the copper foil or copper alloy foil is not particularly limited, but is usually about 140 MPa.

Examples of the composition of the copper foil include tough pitch copper and oxygen-free copper having a purity of 99.9% or more. Moreover, as a composition of copper alloy foil, a well-known copper alloy can be used according to the intensity | strength and electroconductivity requested | required. Known copper alloys include, for example, 0.01-0.3% tin-containing copper alloys and 0.01-0.05% silver-containing copper alloys. Cu- 0.12% Sn and Cu-0.02% Ag are often used.
As the copper foil or copper alloy foil, rolled foil or electrolytic foil can be used. However, in order to set the tensile strength to 250 MPa or less, it is desirable that the rolled foil is an annealed foil. Further, the electrolytic foil has a high tensile strength and is not suitable for use in the present invention as compared with the rolled foil, but if the tensile strength is 250 MPa or less, the electrolytic foil can be used without any problem. However, in the case of an electrolytic foil, even if the tensile strength is high, the elongation of the copper foil itself may exceed 20%, which is preferable because the workability of the copper foil composite is improved. On the other hand, regarding the cut property of the cut surface of the copper foil, the electrolytic foil tends to be inferior to the copper foil having a low tensile strength.

The resin layer combined with the copper foil or the copper alloy foil has a thickness of 10 μm or more and a tensile strength of 200 MPa or more.
If the thickness of the resin layer is less than 10 μm, the strength and elongation of the copper foil composite will depend on the strength and elongation of the copper foil or copper alloy foil, and the elongation of the copper foil composite will be reduced. Although the upper limit of the thickness of a resin layer is not specifically limited, For example, when using a commercially available resin film, the upper limit of the thickness of a resin layer can be about 50 micrometers.
Moreover, if the tensile strength of the resin layer is less than 200 MPa, the strength and elongation of the copper foil composite also depend on the strength and elongation of the copper foil or copper alloy foil, and the elongation as the copper foil composite is reduced. To do.

The resin layer may consist of a single composition such as a resin film. Moreover, when laminating | stacking a resin film on copper foil or copper alloy foil through an adhesive agent, let the resin film and the adhesive resin layer which comprises an adhesive agent be the "resin layer" of this invention.
As the resin layer, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), nylon (registered trademark), polyvinyl alcohol, etc. can be used, but PET is used from the viewpoint of thickness, strength, and price. Most suitable.
As the adhesive resin layer, a polyurethane resin, a combination of an epoxy resin and an elastomer, an acrylic resin, or the like can be used. The thickness of the adhesive resin layer can be, for example, about 10 μm or less. Therefore, when a commercially available resin film having a thickness of about 10 to 50 μm is laminated on a copper foil or a copper alloy foil with an adhesive resin layer, the thickness as the “resin layer” of the present invention is the thickness of the resin film and the adhesive resin layer. Total thickness. The adhesive resin layer generally has a lower mechanical strength than PET, PEN and the like. For this reason, the strength of the resin layer including the adhesive resin layer is approximately equal to the value obtained by dividing the strength of PET, PEN or the like (for example, a resin film) by the sum of the thickness of the resin film and the thickness of the adhesive resin layer.

  In addition, it is possible to provide a back surface adhesive layer on the back surface of the resin layer (the surface opposite to the copper foil side of the resin layer) so that the copper foil composite of the present invention can be easily attached to the target article. However, in that case, the thickness and tensile strength of the resin layer are defined by values of the resin layer excluding the back surface adhesive layer, and the tensile strength and breaking strain of the copper foil composite are defined in a state excluding the back surface adhesive layer.

A general PET film has a tensile strength of 250 MPa or more and an elongation of 100% or more. Further, there are cases where the PET film is subjected to a high stretching process to increase the tensile strength to 280 MPa or more, but in that case, the elongation often decreases to about 70%.
However, when a copper foil or copper alloy foil and a PET film are combined to obtain a copper foil composite, the elongation of the copper foil composite is significantly less than 100% and is 20 to 40%. For this reason, the maximum tensile strength of the PET film cannot be exhibited, the tensile strength of the copper foil composite is also lower than the tensile strength of the PET film, and the workability is improved.

In addition, it is a case where the values such as the tensile strength of the copper foil and the resin layer before manufacturing the copper foil composite are known, and the characteristics of the copper foil and the resin layer change greatly when the copper foil composite is manufactured. When not performing such heat processing, you may employ | adopt the said known value before manufacturing a copper foil composite_body | complex.
Alternatively, the tensile strength of the remaining copper foil may be measured by removing the resin layer from the copper foil composite with a solvent or the like. Similarly, the tensile strength of the resin layer remaining after removing the copper foil from the copper foil composite with an acid or the like may be measured. When the copper foil and the resin layer are laminated via an adhesive, the copper foil and the resin layer are peeled off when the adhesive layer is removed with a solvent, etc., and the tensile strength between the copper foil and the resin layer is separated. Can be measured.

  The copper foil composite preferably has a tensile strength of 200 MPa or less and a breaking strain of 20% or more. When the breaking strain is 20% or more, the copper foil composite is easily stretched, and the workability is further improved.

  The copper foil composite of the present invention is bonded to the target article on the resin layer side, and the exposed surface of the copper foil or copper alloy foil is the front side, so that copper ions flow out from the exposed copper foil or copper alloy foil. Antibacterial action is obtained.

  It goes without saying that the present invention is not limited to the above-described embodiment, but extends to various modifications and equivalents included in the spirit and scope of the present invention.

<Manufacture of copper foil composite>
After hot-rolling a copper ingot having the composition shown in Table 1 and removing the oxide by surface cutting, cold rolling, annealing and pickling are repeated to reduce the thickness to a predetermined thickness, and finally annealing is performed to improve workability. Obtained copper foil was obtained. The tension during cold rolling and the rolling conditions in the width direction of the rolled material were made uniform so that the copper foil had a uniform structure in the width direction. In the next annealing, temperature control was performed using a plurality of heaters so as to obtain a uniform temperature distribution in the width direction, and the copper temperature was measured and controlled. For some samples, a copper alloy foil was obtained using a copper alloy ingot. Table 1 shows the tensile strength, elongation, and thickness of the copper foil and alloy foil.
Next, a commercially available biaxially stretched PET film having the tensile strength, elongation and thickness shown in Table 1 was attached to the copper foil with a polyurethane adhesive (2 μm thickness after adhesion) to produce a copper foil composite.

<Tensile test>
A strip-shaped tensile test piece having a width of 12.7 mm was prepared in advance from a copper foil (alloy foil) before producing a copper foil composite and a PET film, and tensile strength and elongation were measured.
Similarly, a strip-shaped tensile test piece having a width of 12.7 mm was produced from the obtained copper foil composite.
The tensile test was performed under the conditions of a gauge length of 100 mm and a tensile speed of 10 mm / min, and the average value of N10 was adopted as the tensile strength and elongation values. The tensile test of the copper foil composite was stopped when the copper foil was broken, and the tensile strength and elongation at that time were measured as the value of the copper foil composite. Here, the tensile test of the copper foil composite was performed in a state including the polyurethane layer (adhesive resin layer).

<Processability of copper foil composite>
The following criteria were evaluated according to the elongation of the copper foil composite.
A: Elongation of copper foil composite is 20% or more B: Elongation of copper foil composite is less than 20% and 10% or more X: Elongation of copper foil composite is less than 10% <Cutting property of copper foil composite>
The copper foil composite was cut with scissors, the cut surface was touched with a finger, the state of the skin at that portion was observed, and the presence or absence of a flaw was visually determined. Evaluation was made according to the following criteria.
○: No scars are seen on the skin Δ: Fine scars are found on the skin ×: The skin is cut The results obtained are shown in Table 1.

  As is clear from Table 1, in each example, both the workability and the cutability of the copper foil composite were good. However, in the case of Example 4 in which the tensile strength of the copper foil exceeded 200 MPa, the cut property was slightly degraded as compared with the other examples, but there is no practical problem.

On the other hand, in the case of Comparative Examples 1 and 2 in which the thickness of the copper foil exceeded 10 μm, the strength of the cross section of the copper foil was high and the cut property was deteriorated.
Further, in the case of Comparative Example 3 in which the thickness of the resin layer is less than 10 μm, the properties (elongation) of the copper foil composite become dependent on the elongation of the copper foil, and the elongation of the copper foil composite is lowered and the workability is increased. Deteriorated.
In the case of Comparative Example 4 where the tensile strength of copper exceeded 250 MPa, the tensile strength of the copper foil composite also increased, the elongation of the copper foil composite decreased, and the workability deteriorated. Moreover, the strength of the cross section of the copper foil was high, and the cut property was also deteriorated.
In the case of Comparative Example 5 in which the resin layer has a tensile strength of less than 200 MPa, the properties (elongation) of the copper foil composite become dependent on the elongation of the copper foil, the elongation of the copper foil composite is reduced, and the workability is reduced. Deteriorated.

Claims (3)

A copper foil composite having a copper foil or copper alloy foil and a resin layer provided on one side of the copper foil or copper alloy foil,
The thickness of the copper foil or copper alloy foil is 2 μm or more and less than 10 μm, and the tensile strength is 250 MPa or less,
The resin layer is made of polyethylene terephthalate, or a polyethylene terephthalate film, and an adhesive resin layer that bonds the film and the copper foil or copper alloy foil.
A copper foil composite in which the resin layer has a thickness of 10 μm or more and a tensile strength of 200 MPa or more.   The copper foil composite according to claim 1, wherein the copper foil composite has a tensile strength of 200 MPa or less and a breaking strain of 20% or more. The copper foil composite according to claim 1 or 2 used for antibacterial applications .