JP7439515B2 - Manufacturing method of resin bonded body - Google Patents

Description

The present invention relates to a method for manufacturing a resin bonded body having high bonding strength.

BACKGROUND ART For the purpose of further miniaturization of semiconductor devices, improvement of optical characteristics of optical devices, etc., techniques for bonding various base materials without an adhesive (hereinafter referred to as adhesive-less bonding) are being studied. Among these, in adhesive-less bonding between resins, a lamination technique is widely used in which the resin joining surfaces are brought into contact and then heated to the melting temperature of the resin to weld. However, this method has the problem that the crystallinity, molecular structure, etc. of the resin change (thermal deterioration) during heating, which adversely affects optical properties and mechanical strength. Therefore, resin bonding methods have been proposed to obtain strong bonding strength without causing thermal damage.

Patent Document 1 discloses that a resin solution in which a solute containing a silicone resin or a modified silicone resin is dissolved in an organic solvent is injected toward the bonding surface of at least one of two substrates to be bonded to each other. After selectively forming a thin resin layer on an arbitrary region of the bonding surface, an activation solution capable of causing active oxygen in the atomic state to act on the thin resin layer is injected to the thin resin layer. It is disclosed that these joining surfaces can be joined by developing adhesive properties.
In addition, Patent Document 2 discloses that after applying surface treatment to the resin bonding surface using ionized gas or electromagnetic waves, the resin member is pressurized with a solvent interposed between the bonding surfaces of the resin member. It is disclosed that bonding can be performed even at a temperature of less than 50°C.

Japanese Patent Application Publication No. 2010-194964 Japanese Patent Application Publication No. 2007-245654

However, although it is thought that both methods disclosed in Patent Documents 1 and 2 can achieve a certain degree of bonding strength improvement effect, in the method of Patent Document 1, silicone resin or modified silicone resin is not applied to the bonding surface of the substrate. Since it is necessary to form a resin adhesive layer and bond the base materials through the resin adhesive layer, light absorption occurs in the resin adhesive layer. As a result, good optical properties cannot be obtained.
On the other hand, the method of Patent Document 2 requires surface treatment and solvent contact with the bonding surface in order to activate the resin bonding surface in order to develop the bonding force, so the process is complicated.

The present invention has been made in view of the above-mentioned problems, and provides a method for easily manufacturing a resin bonded body having high bonding strength. Furthermore, the present invention provides a method for manufacturing a resin bonded body having good optical properties when the resin to be bonded is a transparent body.

A method for producing a resin bonded body according to the present invention that solves the above problems is a method for producing a resin bonded body in which a first resin member and a second resin member are bonded, the method comprising: activating a liquid to generate a liquid. a liquid activation step of producing an active liquid by generating active species therein; and a surface of the first resin member to be bonded to the second resin member, and/or the first a liquid contacting step of contacting the liquid containing the active species obtained in the liquid activation step with the surface to be joined with the resin member; and after the liquid contacting step, the first resin member and the second and a joining step of pasting together the resin members on their respective surfaces to be joined.

According to the present invention, a method for easily manufacturing a resin bonded body having high bonding strength is provided. Further, according to the present invention, there is provided a method for manufacturing a resin bonded body having good optical properties when the resin to be bonded is a transparent body.

FIG. 1 is a schematic diagram showing an example of the method for manufacturing a resin bonded body of the present invention. FIG. 2 is a schematic diagram showing another example of the method for manufacturing a resin bonded body of the present invention. FIG. 3 is a schematic diagram showing another example of the method for manufacturing a resin bonded body of the present invention.

Examples of embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an example of the method for manufacturing a resin bonded body of the present invention.
As shown in FIG. 1, the method for manufacturing a resin bonded body of the present invention includes a liquid activation step 6 in which active species are generated in a liquid to obtain an active liquid 3, a first resin member 1 and a second resin member 1; A liquid contacting step 7 in which at least one of the joining surfaces of the member 2 is brought into contact with the active liquid 3, and a joining step 8 in which the first resin member 1 and the second resin member 2 are bonded together at their respective joining surfaces. have.

In the liquid activation step 6 in which activated species are generated in the liquid to obtain the active liquid 3, the liquid to be activated is put into the liquid container 9, and then the liquid is activated by the liquid activation means 4.
In the present invention, "active liquid 3" refers to a liquid containing one or more types of active species such as highly reactive atoms/molecules with unpaired electrons (radicals), ions, and electrons (charged particles). Refers to liquid. The degree of activity, which indicates the degree of activation, can be evaluated by, for example, measuring the intensity of light emitted from the active species, chemical quantitative measurement that measures the amount of reaction between the active species and the test solution, or electron spin resonance analysis.

Examples of the liquid to be activated include pure water, methanol, ethanol, acetic acid, and ammonia. This liquid can be selected from a wide range depending on cost, safety, melting resistance of the first resin member 1 and the second resin member 2, and the like. Further, the liquid may be a mixture of two or more types of liquid, an aqueous solution, or the like.

Further, the material and shape of the liquid container 9 are not particularly limited, but if the liquid container 9 dissolves in the liquid used, the components of the liquid container 9 will be mixed into the liquid 3, so unintended components will be mixed into the liquid. It is preferable to use a liquid container 9 made of a material that is resistant to dissolution so as to prevent the liquid from entering.

The liquid activation means 4 may be any method that can dissociate or ionize molecules of the liquid by imparting energy to the liquid, and can be selected as appropriate. In particular, as the liquid activation means 4, it is preferable to irradiate the liquid with an ionized substance, irradiate the liquid with electromagnetic waves, vibrate the liquid with elastic vibration waves, or apply an electric field to the liquid. Any one of these means may be used, or a plurality of types may be used. These means have high liquid decomposition efficiency and can generate many active species in the liquid in a short time. Further, any of the liquid activating means 4 is preferable because the controllability for activating the liquid is high.

In the present invention, an "ionized substance" refers to a gas (ionized gas) or a liquid (ionized liquid) containing charged particles such as ions and electrons. The method of generating the ionized substance is not particularly limited, but examples include a method of applying a voltage (electric field) between metal electrode plates facing each other with a gap therebetween. In addition, methods for irradiating a liquid with ionized substances include transporting the generated ionized substances to the liquid with a gas flow, injecting the liquid to the ionized substance generation area, and using a metal electrode for generating ionized substances in the liquid. An example is arranging a metal electrode plate separate from the plate and applying a DC voltage to attract charged particles.

By irradiating the liquid with ionized gas, the liquid is decomposed and activated. Note that the type of gas for generating the ionized gas is not particularly limited, and examples thereof include argon, helium, oxygen, water vapor, and nitrogen. By changing the gas species, the density of the ionized gas, etc., the type and activity of the active species generated in the liquid can be easily controlled. Thereby, an appropriate active liquid 3 can be created according to the types of the first resin member 1 and the second resin member 2, and the bonding force can be improved.

When a liquid is irradiated with elastic vibration waves (sound pressure), bubbles in the liquid expand and contract, causing them to burst (cavitation). When this cavitation occurs, the gas-liquid interface locally becomes high temperature, and the liquid thermally decomposes, producing active species. By changing the amount of cavitation generated, the degree of activation of the liquid can be controlled. The amount of cavitation generated can be easily controlled by adjusting the input power and frequency of the vibrator that generates the elastic vibration waves, the temperature of the liquid, etc.

In the present invention, "electromagnetic waves" refer to waves formed by changes in electric and magnetic fields in space. The shorter the wavelength of this wave, the greater the energy, and in particular, by irradiating the liquid with electromagnetic waves having a wavelength of 200 nm or less, the liquid can be effectively decomposed. Furthermore, by changing the amount (illuminance), wavelength, etc. of electromagnetic waves, the type and amount of active species generated in the liquid can be easily controlled.

In the present invention, an "electric field" refers to a state where a voltage is applied. By applying this electric field to the liquid, the liquid is electrolyzed and activated. Although the method of generating the electric field is not particularly limited, for example, an electric field is generated by inserting two metal plates into a liquid and applying a potential difference between the metal plates. By changing the distance between the two metal plates, the applied voltage, etc., the electric field strength can be easily changed, and the activity of the liquid can be controlled.

In any of the liquid activation means 4, the reaction rate increases as the temperature of the liquid increases, so increasing the liquid temperature can promote the decomposition of the liquid. Furthermore, a uniform activated liquid 3 can be generated by applying energy with the liquid activation means 4 while stirring the liquid with a stirrer.

The types of the first resin member 1 and the second resin member 2 include polyethylene (PE), polypropylene (PP), polyamide (PA), polyacetal (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), Polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE), etc. can be selected as appropriate depending on the application, but polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile butadiene styrene ( It is preferable to use amorphous materials such as ABS), polymethyl methacrylate (PMMA), polycarbonate (PC), polyetherimide (PEI), and polyamideimide (PAI). This is because the thermal mobility of molecular chains is higher in amorphous materials, and molecular diffusion (entanglement of molecular chains) at the bonding interface between the first resin member 1 and the second resin member 2 becomes larger. As this molecular diffusion increases, the intermolecular force at the bonding interface increases, and the bonding force improves. Furthermore, the first resin member 1 and the second resin member 2 may be of different types, but it is preferable that they be of the same type from the viewpoint of molecular diffusion.

Further, the joint surfaces of the first resin member 1 and the second resin member 2 may be intentionally provided with an uneven shape. For example, a rectangular structure in which the unevenness height and width are 100 nm or more can be mentioned. Examples of the unevenness forming method include laser processing, chemical etching processing, polishing processing, cutting processing, imprint processing, shot peening processing, and the like.

In the liquid contacting step 7 of bringing into contact with the active liquid 3, the active liquid 3 is brought into contact with one or both of the joint surfaces of the first resin member 1 and the second resin member 2 using the liquid contact mechanism 5. . By bringing the active liquid 3 into contact with the bonding surfaces of the first resin member 1 and the second resin member 2, the bonding surfaces of the first resin member 1 and the second resin member 2 are activated, and the bonding surfaces of the first resin member 1 and the second resin member 2 are activated, and the bonding surfaces of the first resin member 1 and the second resin member 2 are strengthened. Bonding force can be obtained. The degree of activity of this joint surface can be easily controlled by the amount of contact with the active liquid 3, the contact time with the active liquid 3, and the like.

In the present invention, "activating" the joint surface means cutting the molecular chains on the surface layer of the joint surface of the first resin member 1 and/or the second resin member 2, and/or adding functional groups. It means to do. By cutting the molecular chains, the thermal mobility of the molecular chains present at the bonding surface can be increased (the softening temperature can be lowered). Furthermore, by adding a functional group, a polar functional group such as a hydroxyl group can be generated. The thermal mobility of this molecular chain can be measured using a nanothermal microscope (nano TA) or the like. Further, the type and amount of polar functional groups produced can be confirmed by infrared absorption spectroscopy (IR) or the like.

Although not particularly limited, the liquid contact mechanism 5 may, for example, send the active liquid 3 from the liquid container 9 with a pump and then inject the active liquid 3 with a spray nozzle, or use a coating machine to transfer the active liquid 3 to the first resin member 1, For example, applying the active liquid 3 to the joint surface of the second resin member 2 may be used.

After the liquid contact step 7, in a bonding step 8, the activated bonding surfaces of the first resin member 1 and the second resin member 2 are pasted together. By pasting them together, the entanglement of the cut molecular chains at the interface between the bonding surface of the first resin member 1 and the bonding surface of the second resin member 2 (hereinafter referred to as molecular diffusion) and the generated polar functional Since the condensation reaction (hereinafter referred to as covalent bond formation) between the groups proceeds, the bonding force of the resin bonded body is improved, and a resin bonded body having strong bonding force can be manufactured. These molecular diffusion and covalent bond formation can be accelerated as the bonding surfaces of the first resin member 1 and/or the second resin member 2 are activated in the liquid contact step 7.

In addition, when laminating the first resin member 1 and the second resin member 2, a press machine or the like is used to separate the first resin member 1 and the second resin member 2 so that no voids are formed at the joint interface due to waviness of the joint surfaces of the first resin member 1 and the second resin member 2. It is preferable to press the resin member 2. This increases the actual contact area between the first resin member 1 and the second resin member 2, and improves the bonding force.

Furthermore, before bonding the activated bonding surfaces of the first resin member 1 and the second resin member 2 together, it is preferable to remove the active liquid 3 remaining on the bonding surfaces using a blower or the like. Thereby, a high-quality resin bonded body without liquid traces can be manufactured.

The higher the temperature of the first resin member 1 and the second resin member 2 in the bonding step 8, the more molecular diffusion and the formation of covalent bonds are promoted, and the bonding force becomes higher. When the temperature of the second resin member 2 exceeds the glass transition temperature (Tg) of the resin forming each resin member, the molecular structure of the resin forming each resin member changes. As a result, the mechanical properties, optical properties, etc. of the first resin member 1 and the second resin member 2 may deteriorate. Therefore, it is preferable that the temperature of the entire first resin member 1 and the entire second resin member 2 be below Tg. Thereby, a high-quality resin bonded body can be manufactured without changing the molecular structure of the resin constituting each resin member. Note that there may be a temperature difference between the temperatures of the first resin member 1 and the second resin member 2 in the bonding step 8.

Further, the bonding step 8 may be performed in an atmospheric pressure atmosphere, but may also be performed in a vacuum environment. In the present invention, "vacuum" refers to a gas pressure below 1013 hPa, which is atmospheric pressure, and the lower the gas pressure in the bonding step 8, the more the risk of bubble generation at the bonding interface can be suppressed.

As heating means for the first resin member 1 and the second resin member 2 in the bonding step 8, an infrared heating machine, a microwave heating machine, an ultrasonic heating machine, a heat press machine, a hot air dryer, a heating furnace, etc. are used. Yes, there are no particular restrictions.

Moreover, after manufacturing the resin bonded body in the bonding step 8, the resin bonded body may be heated afterward. This promotes molecular diffusion at the bonding interface, further improving the bonding strength of the resin bonded body. As a means for post-heating, an infrared heating machine, a microwave heating machine, an ultrasonic heating machine, a heat press machine, a hot air dryer, a heating furnace, etc. can be used, and there is no particular restriction. Further, the temperature of the post-heating is preferably equal to or lower than the glass transition temperature (Tg) of the first resin member 1 and the second resin member 2 from the viewpoint of preventing thermal deterioration.

FIG. 2 is a schematic diagram showing another example of the method for manufacturing a resin bonded body of the present invention. In the method for manufacturing a resin bonded body shown in this figure, in the liquid contact step 7, the first resin member 1 and the second resin member 2 are placed in the active liquid 3 while the liquid activation step 6 is being performed. The first resin member 1 and the second resin member 2 are brought into contact with the active liquid 3 by immersion. When the liquid contact step 7 is also performed during the liquid activation step 6 in this way, the first resin member 1 and the second resin member 2 also receive energy from the liquid activation means 4, so that the contact with the active liquid 3 is performed. The first resin member 1 and the second resin member 2 can be directly activated together with the reaction. Thereby, the joint surfaces of the first resin member 1 and the second resin member 2 can be activated in a short time. In addition, by immersing the first resin member 1 and the second resin member 2 in the active liquid 3, the active liquid 3 is brought into contact with the joint surfaces of the first resin member 1 and the second resin member 2 without leaking. can be done. Furthermore, since the front and back sides of the first resin member 1 and the second resin member 2 can be treated, it is possible to easily manufacture a laminate in which other resin members are stacked in addition to the first resin member 1 and the second resin member. can do.

In the manufacturing method shown in FIG. 2, both the first resin member 1 and the second resin member 2 are immersed in the active liquid 3, but only the joint surface of one of the resin members is activated. If so, it is sufficient to immerse only the resin member in the active liquid 3.

FIG. 3 is a schematic diagram showing yet another example of the method for manufacturing a resin bonded body of the present invention. In the method for manufacturing a resin bonded body shown in this figure, before the liquid contact step 7, a surface treatment step 11 is performed in which the bonding surface of one or both of the first resin member 1 and the second resin member 2 is surface-treated. will be held. In this way, before the liquid contact step 7, the joint surfaces of the first resin member 1 and the second resin member 2 are surface-treated in advance, and the joint surfaces of the first resin member 1 and the second resin member 2 are By cutting molecular chains and/or generating polar functional groups, the reaction with the active liquid 3 is promoted, and the first resin member 1 and the second resin member 2 can be activated in a shorter time. . Furthermore, by performing surface treatment, contaminants adhering to the surfaces of the first resin member 1 and the second resin member 2 can be removed, and a high-quality resin bonded body free of foreign matter can be manufactured. can.

In the manufacturing method of FIG. 3, surface treatment is applied to both the joint surfaces of the first resin member 1 and the second resin member 2, but in the liquid contact step 7, only the joint surface of one of the resin members is subjected to surface treatment. If the resin member is to be activated, surface treatment may be applied only to the bonding surface of the resin member.
Further, in the surface treatment step 11, the active liquid 3 may be brought into contact with the first resin member 1 and the second resin member 2 at the same time as the surface treatment.

The surface treatment means 10 includes irradiating an ionized substance to the joint surface of the first resin member 1 and the second resin member 2, and applying electromagnetic waves to the joint surface of the first resin member 1 and the second resin member 2. It is preferable to irradiate the joint surface of the first resin member 1 and the second resin member 2 with elastic vibration waves. Among these, elastic vibration waves are generated by applying vibrational energy directly to the bonding surfaces of the first resin member 1 and the second resin member 2, whereby molecular chains are severed and the first resin member 1 and the second resin member 2 are bonded together. The resin member 2 can be activated. Moreover, any one of these means may be used, or a plurality of types may be used. Since these surface treatment means 10 have high decomposition efficiency for the first resin member 1 and the second resin member 2, they can modify the surfaces of the first resin member 1 and the second resin member 2 in a short time. I can do it. Furthermore, the activity levels of the first resin member 1 and the second resin member 2 can be easily controlled by changing the processing intensity, time, frequency, etc.

The method for manufacturing a resin bonded body of the present invention will be described below in Examples, but the present invention is not limited to these Examples. Further, the results of Examples and Comparative Examples are shown in Table 1 below.

[Example 1]
In the method for manufacturing the resin bonded body shown in FIG. It was used for a resin member 1 (hereinafter referred to as PET film 1) and a second resin member 2 (hereinafter referred to as PET film 2). In addition, as a result of measuring the surface roughness (arithmetic mean roughness Ra) of PET Film 1 and PET Film 2 using a laser microscope (Olympus Corporation: OLS4100), both were 10 nm.
In the liquid activation step 6, pure water was used as the liquid to be activated, and ionized gas treatment was used as the liquid activation means 4. In the ionized gas treatment, 100 sccm of oxygen gas was supplied between two metal plates under atmospheric pressure, and then a DC pulse voltage (10 kV) was applied to generate ionized gas, and the pure water was irradiated with the ionized gas.
After putting pure water into a stainless steel liquid container 9, the pure water was subjected to ionized gas treatment for 1 minute to generate an active liquid 3.

In the liquid contact step 7, the active liquid 3 was sprayed with a spray nozzle to contact the bonding surfaces of the PET film 1 and the PET film 2, respectively.
In the bonding step 8, the temperature of the PET film 1 and the PET film 2 was set to 65° C., and the bonding surfaces were heat-pressed at 2 MPa for 10 minutes in a press to bond the PET film 1 and the PET film 2. .
The bonding strength of the bonded sample prepared above was evaluated using a 90 degree peel tester (Shimadzu Corporation: AGS-100A). At that time, the peeling speed was 5 cm/min. As a result, the bonding force of the bonded sample was 0.8 N/cm. Further, the total light transmittance (Nippon Denshoku Kogyo: NDH2000) of the bonded sample was measured and found to be 89%.

[Example 2]
As shown in FIG. 2, while the liquid activation step 6 is being performed, both the PET film 1 and the PET film 2 are immersed in the active liquid 3, and the active liquid 3 is brought into contact with the PET film 1 and the PET film 2. A bonded sample of PET film 1 and PET film 2 was created under the same conditions as in Example 1, except for performing the liquid contact step 7.
The bonding force of the bonded sample created above was 1.2 N/cm. Furthermore, the total light transmittance of the bonded sample was measured and was 89%.

[Example 3]
As shown in FIG. 3, a bonded sample of PET film 1 and PET film 2 was created under the same conditions as in Example 1, except that surface treatment step 11 was performed before liquid contact step 7. Note that ionized gas treatment was used as the surface treatment means 10, and the joint surface of the PET film 1 and the PET film 2 was treated for 10 seconds. In addition, in the ionized gas treatment, oxygen gas was supplied at 100 sccm between two metal plates under atmospheric pressure, and then a DC pulse voltage (10 kV) was applied to generate ionized gas, and the pure water was irradiated with the ionized gas.
The bonding force of the bonded sample created above was 1.1 N/cm. Furthermore, the total light transmittance of the bonded sample was measured and was 89%.

[Example 4]
The first resin member 1 and the second resin member 2 were both changed to a PMMA base material (Technoloy (registered trademark) S000 (transparent), glass transition temperature 100°C) with a thickness of 0.2 mm (hereinafter referred to as the first resin member 1 and the second resin member 2). A bonded sample of PMMA1 and PMMA2 was prepared under the same conditions as in Example 3, except that the base material temperature in bonding step 8 was 95° C. Created.
The bonding force of the bonded sample created above was 1.5 N/cm. Furthermore, the total light transmittance of the bonded sample was measured and found to be 91%.

[Comparative example 1]
A bonded sample of PET film 1 and PET film 2 was prepared under the same conditions as in Example 1 except that the pure water was not activated.
The bonding force of the bonded sample created above was 0.0 N/cm.

[Comparative example 2]
A bonded sample of PET film 1 and PET film 2 was created under the same conditions as in Example 3, except that the pure water was not activated.
The bonding force of the bonded sample created above was 0.6 N/cm. Furthermore, the total light transmittance of the bonded sample was measured and was 89%.

By using the method for manufacturing a resin bonded body of the present invention, a resin bonded body with high bonding strength can be easily obtained, and when a resin bonded body is manufactured using a transparent resin, it has good optical properties. A resin bonded body having the following can be manufactured. The resin bonded body produced by the method for producing a resin bonded body of the present invention can be applied, for example, to packaging materials and optical films, but the scope of its application is not limited to these.

1 First resin member 2 Second resin member 3 Activated liquid 4 Liquid activation means 5 Liquid contact mechanism 6 Liquid activation process 7 Liquid contact process 8 Bonding process 9 Liquid container 10 Surface treatment means 11 Surface treatment process

Claims (6)

A method for manufacturing a resin joined body in which a first resin member and a second resin member are joined,
a liquid activation step of activating a liquid to generate active species in the liquid to obtain an active liquid;
The liquid obtained in the liquid activation step is applied to the surface of the first resin member that is bonded to the second resin member and/or the surface of the second resin member that is bonded to the first resin member. a liquid contacting step of contacting the active liquid;
After the liquid contacting step, the method includes a joining step of laminating the first resin member and the second resin member on their respective surfaces to be joined.
Before performing the liquid contact step, a surface of the first resin member to be bonded to the second resin member and/or a surface of the second resin member to be bonded to the first resin member is applied. A method for manufacturing a resin bonded body , which includes a surface treatment process . The means for activating the liquid in the liquid activation step includes irradiating the liquid with an ionized substance, irradiating the liquid with electromagnetic waves, vibrating the liquid with elastic vibration waves, and applying an electric field to the liquid. 2. The method for producing a resin bonded body according to claim 1, wherein the method comprises applying at least one of the following: The liquid contact step includes contacting the active liquid by immersing the first resin member and/or the second resin member in the active liquid during the liquid activation step. The method for producing a resin bonded body according to claim 1 or 2. The means for applying the surface treatment in the surface treatment step is a surface of the first resin member that is bonded to the second resin member, and/or a surface of the second resin member that is bonded to the first resin member. Any one of claims 1 to 3 , wherein the surface is irradiated with an ionized substance, irradiated with an electromagnetic wave, and vibrated with an elastic vibration wave. A method for producing a resin bonded body according to . In the bonding step, the temperature of the entire first resin member is set to be equal to or lower than the glass transition temperature of the resin constituting the first resin member, and the temperature of the entire second resin member is set to be lower than the glass transition temperature of the resin constituting the second resin member. The method for producing a resin bonded body according to any one of claims 1 to 4 , wherein the glass transition temperature is lower than or equal to the glass transition temperature. The method for manufacturing a resin bonded body according to any one of claims 1 to 5 , wherein the first resin member and the second resin member are amorphous materials.

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