Method for joining resin members

Abstract

A method for joining resin members, comprising: a coating film forming step of forming a coating film by applying a solvent to a surface of a resin member, the solvent having a swelling degree of 1.05 or more and 3.00 or less when a thermoplastic resin is swelled, and a boiling point B°C of R°C or less when a glass transition temperature of the thermoplastic resin is set to R°C; a lamination step of laminating the resin members to each other with the coating film interposed therebetween to form a laminate; and a heating and pressurizing step of pressurizing the laminate in a lamination direction while heating the laminate at a heating temperature H°C of R°C or less.

Description

Technical Field

[0001] This invention relates to a method for joining resin components. Background Technology

[0002] In recent years, structures that join plate-like resin components together, such as microchannel chips, have attracted much attention.

[0003] Microchannel chips are chip-shaped structures that include microchannels at the micrometer scale formed using microfabrication techniques and reaction vessels. Microchannel chips are used in various fields such as the analysis and inspection of biological substances such as DNA, RNA, and proteins; drug development and pharmaceutical research; organic synthesis; and water quality analysis. Furthermore, resin-based microchannel chips, which can be manufactured at low cost, are attracting considerable attention.

[0004] Furthermore, various studies have been conducted to date regarding methods for manufacturing resin-based microchannel chips. For example, Patent Document 1 discloses a method for bonding a microchip, characterized in that an organic solvent is applied to the channelless portion of a substrate having microchannels on its surface, and then overlapped with a substrate serving as a cover for fusion bonding. Additionally, Patent Document 2 discloses bonding two substrates formed of cyclic olefin polymers or cyclic olefin copolymers through an adhesive layer containing paraffin or cycloalkanes.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2005-080569;

[0008] Patent Document 2: International Publication No. 2009 / 131070. Summary of the Invention

[0009] The problem the invention aims to solve

[0010] When joining resin components using the conventional bonding method described above, the substrate may deform or exhibit poor appearance during bonding. Furthermore, in conventional bonding methods, solvent residue may remain at the bonding area.

[0011] Therefore, the object of the present invention is to provide a method for joining resin components that can suppress solvent residue at the joining portion when joining resin components, and can suppress deformation and poor appearance of the resin components constituting the joint.

[0012] Solution for solving the problem

[0013] The inventors conducted in-depth research to solve the above-mentioned problems. As a result, a new discovery was made: a solvent used for bonding is selected that has a boiling point equal to or lower than the glass transition temperature of the thermoplastic resin constituting the resin component, and whose degree of swelling when the resin swells is within a specified range. Furthermore, when bonding the resin components through a coating formed by this solvent, a heating and pressurizing process is performed. This suppresses solvent residue at the bonding portion, and the resin components are less prone to deformation and poor appearance, thus completing the present invention.

[0014] That is, the object of the present invention is to advantageously solve the above-mentioned problems. The bonding method between resin components of the present invention is a bonding method between at least two resin components comprising a thermoplastic resin, comprising: a coating film forming step, wherein a solvent is applied to at least one surface of the resin components to form a coating film, wherein the solvent is a solvent that causes the thermoplastic resin to swell to have a swelling degree of 1.05 or more and 3.00 or less, and whose boiling point B°C is R°C or less when the glass transition temperature of the thermoplastic resin is set to R°C; a lamination step, wherein the at least two resin components are laminated together with the coating film to form a laminate; and a heating and pressurizing step, wherein the laminate is heated at a heating temperature H°C or less to R°C while pressurizing in the lamination direction. As the solvent used for bonding, a solvent with a boiling point that is equal to or lower than the glass transition temperature of the thermoplastic resin constituting the resin component and whose degree of swelling when the resin swells is within a specified range is selected. Furthermore, when bonding the resin components through a coating film formed by the solvent, a heating and pressurizing process is performed. This can suppress solvent residue at the bonding part and suppress deformation and poor appearance of the resin component.

[0015] Here, the "degree of swelling" when the thermoplastic resin swells with a solvent can be measured according to the method described in the examples of this specification. Furthermore, the "glass transition temperature" of the thermoplastic resin can be measured according to the method described in the examples of this specification. Moreover, the "boiling point" of the solvent refers to the boiling point at 1 atm.

[0016] Furthermore, in the bonding method between resin components of the present invention, at least one of the at least two resin components may be a transparent resin component. Moreover, in the bonding method between resin components of the present invention, both of the at least two resin components may be transparent resin components.

[0017] Furthermore, in the bonding method between resin components of the present invention, it is preferable that the heating temperature H°C in the above-mentioned heating and pressurizing process is (R-20)°C or less. If the heating temperature H°C in the heating and pressurizing process is more than 20°C lower than the glass transition temperature R°C of the thermoplastic resin, deformation of the resin component can be further effectively suppressed.

[0018] Furthermore, in the bonding method between resin components of the present invention, it is preferable to include a preheating step between the lamination step and the heating and pressurizing step, in which the laminate is preheated at a temperature of (B+25)°C or lower. By preheating the laminate at a temperature range not exceeding the boiling point of the solvent (B°C+25°C) before the heating and pressurizing step, the resin components can be bonded even better.

[0019] Invention Effects

[0020] According to the present invention, a method for joining resin components can be provided, which can suppress solvent residue at the joining portion when joining resin components, and can suppress deformation and poor appearance of the resin components constituting the joint. Attached Figure Description

[0021] Figure 1A This is a top view showing an example of a channel substrate for a microchannel chip manufactured in the embodiments and comparative examples.

[0022] Figure 1B This is a top view showing an example of a cover substrate for a microchannel chip manufactured in the embodiments and comparative examples. Detailed Implementation

[0023] The following is a detailed description of one embodiment of the present invention. The bond obtained by the bonding method between resin components of the present invention can be widely used in the medical, biological, and optical fields; specifically, it can be used as a microchannel chip and a perforated plate.

[0024] (Methods for joining resin components)

[0025] The bonding method between resin components of the present invention is a bonding method between at least two resin components comprising a thermoplastic resin, comprising: a coating film forming step, wherein a solvent is applied to at least one surface of the resin component to form a coating film, wherein the solvent is a solvent whose degree of swelling when the thermoplastic resin swells is 1.05 or more and 3.00 or less, and whose boiling point B is below R when the glass transition temperature of the thermoplastic resin is set to R °C; a lamination step, wherein at least two resin components are laminated together with the coating film in between to form a laminate; and a heating and pressurizing step, wherein the laminate is heated at a heating temperature H °C below R °C while pressurizing in the lamination direction. In the bonding method of the present invention, the solvent used for bonding is selected to have a boiling point that is equal to or lower than the glass transition temperature of the thermoplastic resin constituting the resin component and a swelling degree that is within a specified range when the resin swells. Furthermore, when the resin components are bonded together through a coating film formed by the solvent, a heating and pressurizing process is performed. As a result, solvent residue in the bonding portion of the resulting bond can be suppressed, and deformation and poor appearance of the resin component constituting the bond can be suppressed.

[0026] <Thermoplastic Resins>

[0027] Thermoplastic resins that can constitute resin components that are the bonding objects in the bonding method of the present invention are not particularly limited, and examples include cyclic olefin resins, polycarbonate resins, aromatic polyetherketone resins, and (meth)acrylic resins. These can be used alone or in combination. Among these, cyclic olefin resins are preferred from the perspective of exhibiting advantageous properties such as precise moldability, low water absorption, low birefringence, and low fluorescence. Furthermore, in this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0028] Cyclic olefin resins are polymers or copolymers obtained by polymerizing monomers such as those described later, or their hydrides. Cyclic olefin polymers can be crystalline or amorphous, but are preferably amorphous. Norbornene monomers are preferably used as repeating units in forming cyclic olefin polymers. Norbornene monomers are monomers containing a norbornene ring. Examples of norbornene monomers include, for example, bicyclic [2.2.1]hept-2-ene (common name: norbornene), 5-ethylidene-bicyclic [2.2.1]hept-2-ene (common name: ethylidene norbornene), and their derivatives (derivatives with substituents on the ring); tricyclic [5.2.1.0]hept-2-ene, etc. 2,6 [Dec-3,8-diene (common name: dicyclopentadiene), and its derivatives, etc., are tricyclic monomers; tetracyclic [7.4.0.0] 2,7 .1 10,13 [Tetradecane-2,4,6,11-tetraene (common name: bridged methylenetetrahydrofluorene), tetracyclic [6.2.1.1] 3,6 .0 2,7 Dodecyl-4-ene (common name: tetracyclic dodecylene), 9-ethylidene tetracyclo[6.2.1.1] 3,6 .0 2,7 Tetracyclic monomers, such as dodecyl-4-ene and their derivatives, are available. These monomers may have substituents at any position. Furthermore, the cyclic olefin polymers may be addition polymers, ring-opening polymers, or their hydrides, preferably ring-opening polymers or ring-opening polymer hydrides.

[0029] Considering its application in steam sterilization, the glass transition temperature R℃ of the thermoplastic resin is preferably 125℃ or higher, more preferably 130℃ or higher. If the glass transition temperature R℃ of the thermoplastic resin is above the above lower limit, deformation of the resin component of the resulting bond can be further effectively suppressed.

[0030] <Resin Components>

[0031] The resin component used for bonding is primarily composed of the aforementioned thermoplastic resin, and may also contain additives such as antioxidants as needed. The proportion of thermoplastic resin in the resin component is not particularly limited; it may be 90% by mass or more, or even 100% by mass. Furthermore, of the at least two resin components used for bonding, at least one may be a transparent resin component, or both may be transparent resin components. Here, in this invention, "transparent" means that the total light transmittance is 80% or more when measured using a turbidimeter (manufactured by Nippon Denshoku Kogyo Co., Ltd., NDH 300A) according to the method of JIS K7105. Moreover, the resin component may be a resin component that has undergone surface treatment such as hydrophilic treatment, or it may be a resin component that has not undergone surface treatment.

[0032] Solvent

[0033] As a solvent, solvents that satisfy at least the following two conditions can be cited.

[0034] 1) The degree of swelling of the thermoplastic resin constituting the resin component is 1.05 or more and 3.00 or less when it swells.

[0035] 2) It has a boiling point (B°C) that is equal to or lower than the glass transition temperature (R°C) of the thermoplastic resin constituting the resin component.

[0036] Regarding condition 1) above, the degree of swelling is preferably 1.20 or more, more preferably 1.30 or more, even more preferably 1.50 or more, preferably 2.80 or less, and more preferably 2.50 or less. By using a solvent that causes the thermoplastic resin constituting the resin component to swell with a degree of swelling of 1 or more than the aforementioned lower limit, the bonding between the resin components can be improved. Furthermore, by using a solvent that causes the thermoplastic resin constituting the resin component to swell with a degree of swelling of 1 or less than the aforementioned upper limit, deformation of the resin component after bonding can be effectively suppressed.

[0037] Regarding condition 2) above, the boiling point B°C of the solvent is preferably (R-10)°C or lower, more preferably (R-20)°C or lower, and even more preferably (R-40)°C or lower. Furthermore, as mentioned above, "R°C" refers to the glass transition temperature of the thermoplastic resin constituting the resin component. If the boiling point B°C of the solvent is below the aforementioned upper limit, the amount of residual solvent remaining in the resulting bond can be reduced. Here, when multiple resin components to be bonded are composed of different thermoplastic resins, a lower glass transition temperature is set as "R°C" to select the solvent. Furthermore, when the solvent is a mixed solvent, the boiling point of the average value weighted by the mixing ratio satisfies condition 2) above. Additionally, when residual solvent remains in the bond, it becomes a cause of gas release during use of the bond (e.g., a microchannel chip), which is undesirable. The lower limit of the boiling point B°C of the solvent is not particularly limited and can be, for example, 30°C or higher.

[0038] The solvent used can be appropriately selected in a manner that satisfies conditions 1) and 2) above in its relationship with the thermoplastic resin constituting the resin component. For example, when using the cyclic olefin resin (manufactured by Zeon Corporation, Japan, "ZEONEX 690R", glass transition temperature: 136°C) used in the embodiments described later as the thermoplastic resin, tetrahydrofuran (swelling degree: 1.58, boiling point: 65°C), tetrahydropyran (swelling degree: 2.15, boiling point: 88°C), 2-methyltetrahydrofuran (swelling degree: 1.76, boiling point: 80.2°C), and 1-hexene (swelling degree: 1.41, boiling point: 63°C) can be used as the solvent. Among these, tetrahydrofuran, tetrahydropyran, and 2-methyltetrahydrofuran are preferred as solvents.

[0039] <Coating Formation Process>

[0040] In the coating formation process, a solvent that causes the thermoplastic resin to swell to a degree of swelling of 1.05 or more and 3.00 or less, and whose glass transition temperature of the thermoplastic resin is set to R℃ and whose boiling point B℃ is R℃ or less, is applied to at least one surface of a resin component to form a coating film. The coating film can be formed on both surfaces of two adjacent resin components when the composite is formed, and the coating films can be in contact with each other when the composite is formed, or it can be formed on one of two adjacent resin components when the composite is formed. Wherein, when the target bonding body is a structure containing a groove structure, such as a microchannel chip, it is preferable not to form a coating film on the substrate side having the groove structure (i.e., the channel substrate in the microchannel chip), but only on the substrate side without the groove structure (i.e., the cover substrate in the microchannel chip).

[0041] For example, when the target bonding body is a microchannel chip, the width, depth, and shape of the microchannels in the channel substrate can be appropriately varied according to the application of the microchannel chip, typically in the millimeter range or less, but can be in the nanometer range, preferably in the micrometer range. Specifically, the width of the microchannel is not particularly limited and can be, for example, 10 μm or more and 800 μm or less.

[0042] Furthermore, for example, when the target bonding body is a microchannel chip, a cover substrate can be used that has a smooth surface capable of covering the channel substrate and optionally has a through hole that serves as an injection port for injecting samples into the microchannels of the channel substrate when the microchannel chip is formed together with the channel substrate. Moreover, the cover substrate is bonded to the channel substrate with its smooth surface side as the bonding surface. Alternatively, a substrate with microchannels formed on the surface opposite to the smooth surface side bonded to the channel substrate can also be used as the cover substrate.

[0043] The solvent application rate relative to the surface of the resin component during the coating process is preferably 0.5 mg / cm². 2 The above, more preferably 1.0 mg / cm³ 2 The above is further preferred to be 2.0 mg / cm³. 2 The above, preferably 10.0 mg / cm³ 2 The following is more preferably 5.0 mg / cm³ 2 The following applies. If the coating amount is above the lower limit mentioned above, the resin components can bond even better. Furthermore, if the coating amount is below the upper limit mentioned above, the occurrence of appearance defects such as whitening and cracking in the resulting bond can be further effectively suppressed.

[0044] <Layering Process>

[0045] In the lamination process, at least two resin components are laminated together with a coating film in between to form a laminate. Furthermore, when the target substrate is a microchannel chip, the smooth surface of the cover substrate is laminated with the channel-forming surface of the channel substrate facing each other.

[0046] <Preheating process>

[0047] In a preheating process that can be implemented arbitrarily, the laminate is preheated at a temperature of (B+25)°C or lower. In the preheating process, it is preferable to perform preheating without pressurizing the laminate. The preheating temperature in the preheating process is preferably (B+15)°C or lower, more preferably B°C or lower. As mentioned above, "B°C" is the boiling point of the solvent at 1 atm. If the preheating temperature is below the upper limit mentioned above, the resin components can bond more effectively. Furthermore, the lower limit of the preheating temperature can be, for example, 30°C or higher.

[0048] Furthermore, the preheating time in the preheating process can be, for example, more than 10 seconds and less than 120 seconds. If the preheating time is within the above range, the resin components can be bonded even better.

[0049] The specific implementation method of the preheating process is not particularly limited. For example, when using a flat plate pressing device to perform the heating and pressurizing process described later, the preheating process can be performed by setting the lower heating plate of the flat plate pressing device to a preheating temperature and placing the laminate on it. Alternatively, the preheating process can also be performed using, for example, a preheating furnace set to a preheating temperature.

[0050] <Heating and Pressurization Process>

[0051] In the heating and pressurizing process, the laminate is heated at a heating temperature H°C below R°C while being pressurized in the lamination direction. The heating temperature H°C is preferably below (R-10)°C, more preferably below (R-20)°C, preferably above 20°C, and more preferably above 40°C. If the heating temperature H°C is below the aforementioned upper limit, deformation of the resulting bond can be effectively suppressed. If the heating temperature H°C is above the aforementioned lower limit, appearance defects such as whitening and cracking of the resulting bond can be further effectively suppressed. Furthermore, when the resin component to be bonded is composed of different thermoplastic resins, the lower glass transition temperature is set as "R°C" to determine the heating temperature H°C.

[0052] The pressure applied during the heating and pressurizing process is preferably 0.1 MPa or more, more preferably 0.3 MPa or more, even more preferably 0.5 MPa or more, preferably 10 MPa or less, more preferably 5.0 MPa or less, and even more preferably 3.0 MPa or less. If the pressure applied during the heating and pressurizing process is at or above the lower limit mentioned above, it is possible to suppress the formation of unbonded portions between the resin components, thereby further improving the bonding between the resin components. If the pressure applied during the heating and pressurizing process is at or below the upper limit mentioned above, it is possible to further effectively suppress deformation of the resulting bonded body.

[0053] The pressurization time in the heating and pressurizing process is preferably 1 second or more, more preferably 10 seconds or more, preferably 10 minutes or less, and more preferably 5 minutes or less. By setting the pressurization time to the lower limit or above, the resin components can be bonded more effectively. By setting the pressurization time to the upper limit or below, deformation of the resulting bond can be further effectively suppressed.

[0054] The heating and pressurizing process is not particularly limited and can be implemented using any unit or apparatus. Examples of such units or apparatus include: an apparatus having a unit for pressing the laminate using a flat plate (hereinafter sometimes referred to as a flat plate pressing apparatus); a roller pressing apparatus; and an apparatus that seals the laminate in a vacuum bag and places it in an autoclave for heating and pressurizing. From the viewpoint of improving manufacturing efficiency and the quality of the resulting laminate, flat plate pressing is preferred for implementing the heating and pressurizing process. Furthermore, the heating temperature used for heating and pressurizing using flat plate pressing and roller pressing is the highest temperature among the multiple pressing plates and rollers used, and the heating temperature H°C in the heating and pressurizing process.

[0055] Example

[0056] The present invention will now be described in detail based on embodiments, but the present invention is not limited to these embodiments.

[0057] <Methods for Determination and Evaluation of Physical Properties>

[0058] The determination and evaluation of various physical properties shall be carried out according to the following methods.

[0059] <Methods for determining the degree of swelling>

[0060] Using the same thermoplastic resin as that used in the examples and comparative examples to form the resin components, a 10×10×0.5 mm swelling test piece was prepared. Based on JIS K 7114:2001, the swelling degree was calculated by the ratio of the mass of the test piece before and after immersion in 2 mL of solvent at 23°C for 24 hours (mass after immersion / mass before immersion). Furthermore, test pieces that completely dissolved after immersion or those that could not maintain their shape and became irremovable were defined as "dissolved".

[0061] (Method for determining glass transition temperature)

[0062] The glass transition temperature (R) was determined using a differential scanning calorimeter (Nanotechnology, product name: DSC6220SII) based on JIS-K7121, with a heating rate of 10 °C / min.

[0063] (Poor appearance)

[0064] For each sample prepared in the examples and comparative examples, visual inspection was conducted to confirm whether there were any cracks in the channel substrate or cover substrate, or any defects such as turbidity in the channel portion or joint portion, and the following criteria were used for evaluation.

[0065] A: No cracks, cloudiness, or other defects in appearance.

[0066] B: Cracks or whitening less than 2mm only appear at the ends.

[0067] C: Cracks or cloudiness that do not conform to the evaluation criteria of B.

[0068] (Jointed state)

[0069] The bonding state between the resin components in the joints obtained in the examples and comparative examples was evaluated by the following liquid delivery test.

[0070] For each sample prepared in the examples and comparative examples, a pressure-controlled, pulsation-free pump (manufactured by Takasago Electric Industry Co., Ltd.) was used to inject ink solution into each channel of the microchannel chip through the injection port. The outlet side was sealed with silicone rubber, and the injection pressure was increased to 650 kPa and maintained for 3 minutes. Then, the presence or absence of ink solution seeping from the channels to the junction was visually confirmed, and the evaluation was performed according to the following criteria.

[0071] A: No leakage or seepage was observed during the liquid delivery test.

[0072] B: There was leakage and seepage during the liquid delivery test.

[0073] C: Peeling during the liquid delivery test.

[0074] (Deformation state)

[0075] Five unbonded channel substrates were prepared, and the average cross-sectional area S0 of each channel cut orthogonally to the channel center portion was measured using a field emission scanning electron microscope (Hitachi High-technologies, "SU8220"); and the average cross-sectional area S1 of each channel cut orthogonally to the channel center portion of each sample was measured. Then, the channel shape retention rate was calculated according to the following formula and evaluated according to the following criteria.

[0076] Channel shape retention rate (%) = S1 / S0 × 100

[0077] A: More than 95%

[0078] B: 90% or more but less than 95%

[0079] C: 80% or more but less than 90%

[0080] D: Less than 80%

[0081] (Residual solvent)

[0082] For test pieces cut from the center of the unbonded channel substrate and cover substrate with a size of 5×5 mm, and for test pieces cut from the center of each sample prepared according to the same steps as in the examples and comparative examples with a size of 5×5 mm, the mass reduction when heated to 350°C was measured using a differential thermogravimetric analyzer (Hitachi High-Tech Science, "STA7200") (measurement conditions described below). The average mass reduction rate of the test pieces of the unbonded channel substrate and cover substrate was set as W0 (ppm), and the mass reduction rate of the test pieces of each sample was set as W1 (ppm). The residual solvent amount was calculated from the difference between W1 and W0, and the evaluation was carried out according to the following criteria.

[0083] Measurement conditions

[0084] • Environment: Nitrogen

[0085] • Heating rate: 10℃ / minute

[0086] • Starting temperature: 20℃

[0087] • Holding time at 350℃: 1 hour

[0088] Evaluation Criteria

[0089] A: Less than 10ppm

[0090] B: 10 ppm or higher but less than 100 ppm

[0091] C: Above 100ppm

[0092] (Example 1)

[0093] Fabrication of Channel Substrate and Cover Substrate

[0094] Particles of a cyclic olefin resin containing monomer units derived from norbornene monomers (Zeon Corporation, "ZEONEX 690R", glass transition temperature: 136°C) were dried at 110°C for 5 hours. Then, using a conventional method, the particles were injection molded in an injection molding machine (FANUC ROBOSHOT α100B) at a resin temperature of 280°C, a mold temperature of 100°C, and a holding pressure of 80 MPa to obtain a channel substrate and a cap substrate. The thickness of each substrate (the thickness of the portion of the channel substrate not forming a channel) was 2 mm.

[0095] The channel substrate obtained by injection molding contains, on one side, elements such as... Figure 1A The channel substrate 10 has four channels 11 (width: 100μm, depth: 100μm) with end 12 at both ends, as shown.

[0096] In addition, such as Figure 1B As shown, the cover substrate obtained by injection molding is a cover substrate 20 having eight through holes 21 (injection ports) with a diameter of 2.0 mm. In addition, the position of the through holes 21 corresponds to the position of the end 12 of the channel 11 of the channel substrate 10.

[0097] <Coating Formation Process>

[0098] 50 μL of tetrahydrofuran (boiling point at 1 atm: 65 °C) as a solvent was applied to the entire surface of one side of the cover plate obtained as described above to form a coating film. At this time, the specific gravity of tetrahydrofuran was 0.88, and the coating amount was 2.2 mg / cm³. 2 .

[0099] <Layering Process>

[0100] A laminate is formed by stacking the channel substrate and the cover substrate together such that the channel-containing side of the channel substrate is in contact with the coating-containing side of the cover substrate. In the laminate, the channel substrate and the cover substrate are adjacent to each other with the coating separated by the coating.

[0101] <Preheating process>

[0102] The lower heating plate of a vacuum pressurizing device (Mikado Technos, "VS30-3030") used as a flat plate pressing apparatus is heated to 30°C, and the aforementioned laminate is placed on it with the cover plate side becoming the lower heating plate side. Here, the boiling point B of tetrahydrofuran, used as a solvent, is 65°C, therefore the temperature of the lower heating plate at 30°C is equivalent to (B-35)°C. The preheating time is 30 seconds.

[0103] <Heating and Pressurization Process>

[0104] Before the heating and pressurizing process, the upper heating plate of the vacuum heat pressurizing device is also heated to 30°C. Then, 30 seconds after the preheating process begins, the heating and pressurization of the laminate begins through the upper heating plate. The heating and pressurizing time is 2 minutes, and the pressurization pressure is 1 MPa.

[0105] For the microchannel chip that was obtained as a conjugate, various measurements and evaluations were performed as described above. The results are shown in Table 1.

[0106] (Example 2)

[0107] The temperature settings of the upper and lower heating plates of the vacuum heat pressurization device were changed to 60°C. Otherwise, all operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0108] (Example 3)

[0109] The temperature settings of the upper and lower heating plates of the vacuum heat pressurization device were changed to 80°C. Otherwise, all operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0110] (Example 4)

[0111] Tetrahydropyran was used instead of tetrahydrofuran as the solvent. Furthermore, the temperature settings of the upper and lower heating plates of the vacuum thermopressurization apparatus were changed to 80°C. Otherwise, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0112] (Example 5)

[0113] The temperature settings of the upper and lower heating plates of the vacuum heat pressurization device were changed to 100°C. Otherwise, all operations, measurements, and evaluations were performed in the same manner as in Example 4. The results are shown in Table 1.

[0114] (Example 6)

[0115] 2-Methyltetrahydrofuran was used instead of tetrahydrofuran as the solvent. Furthermore, the temperature settings of the upper and lower heating plates of the vacuum thermopressurization apparatus were changed to 80°C. Otherwise, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0116] (Example 7)

[0117] The temperature settings of the upper and lower heating plates of the vacuum heat pressurization device were changed to 90°C. Otherwise, all operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0118] (Example 8)

[0119] The temperature setting of the upper heating plate of the vacuum heat pressurization device was changed to 100°C, and the temperature setting of the lower heating plate was changed to 60°C. Otherwise, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0120] (Example 9)

[0121] Tetrahydropyran was used instead of tetrahydrofuran as the solvent. Furthermore, the temperature setting of the upper heating plate of the vacuum heat pressurization apparatus was changed to 120°C, and the temperature setting of the lower heating plate was changed to 80°C. Otherwise, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0122] (Comparative Example 1)

[0123] Cyclohexane was used instead of tetrahydrofuran as the solvent. Furthermore, the temperature settings of the upper and lower heating plates of the vacuum thermopressurization apparatus were changed to 80°C. Otherwise, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0124] (Comparative Example 2)

[0125] Acetone was used instead of tetrahydrofuran as the solvent. Furthermore, the temperature settings of the upper and lower heating plates of the vacuum thermopressurization apparatus were changed to 50°C. Otherwise, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0126] (Comparative Example 3)

[0127] Hexadecane was used instead of tetrahydrofuran as the solvent, and the temperature settings of the upper and lower heating plates of the vacuum thermopressurization apparatus were changed to 110°C. Otherwise, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0128] (Comparative Example 4)

[0129] Cyclohexanone was used instead of tetrahydrofuran as the solvent. Furthermore, the temperature settings of the upper and lower heating plates of the vacuum thermopressurization apparatus were changed to 140°C. Otherwise, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0130] Additionally, in Table 1,

[0131] "THF" stands for tetrahydrofuran.

[0132] "THP" stands for tetrahydropyran.

[0133] [Table 1]

[0134]

[0135] As can be seen from Table 1 and the description of the above embodiments, the following bonding method between resin components can suppress solvent residue in the bonding portion when the resin components are bonded, and can suppress deformation and appearance defects of the resin components constituting the bond. The bonding method between resin components includes: a coating forming step, using a solvent that causes the thermoplastic resin to swell to a degree within a specified range and has a boiling point B°C that is equal to or lower than the glass transition temperature R°C of the thermoplastic resin; a lamination step, laminating the resin components together with the coating to form a laminate; and a heating and pressurizing step, heating the laminate at a heating temperature H°C lower than R°C while applying pressure.

[0136] On the other hand, it can be seen that in Comparative Examples 1, 2, and 4, which use solvents that do not meet the specified range when the thermoplastic resin swells, and in Comparative Example 3, which uses solvents with boiling points higher than the glass transition temperature of the thermoplastic resin, the occurrence of appearance defects and deformation in the joint cannot be suppressed (Comparative Examples 1 and 4), or even cannot be joined (Comparative Example 2), or the amount of residual solvent cannot be reduced (Comparative Example 3).

[0137] Industrial availability

[0138] According to the present invention, a method for joining resin components can be provided, which can suppress solvent residue in the joining portion when joining resin components, and can suppress deformation and poor appearance of the resin components constituting the joint.

[0139] Explanation of reference numerals in the attached figures

[0140] 10: Channel substrate;

[0141] 11: Channel;

[0142] 12: Both ends;

[0143] 20: Cover substrate;

[0144] 21: Through hole.

Claims

1. A method for joining resin components, comprising joining at least two resin components, wherein the resin components are resin components comprising thermoplastic resin, and the method for joining the resin components includes: In the coating film forming process, a solvent is applied to at least one surface of the resin component to form a coating film, wherein the solvent is a solvent that causes the thermoplastic resin to swell to a degree of swelling of 1.05 or more and 3.00 or less, and whose boiling point B is below R when the glass transition temperature of the thermoplastic resin is set to R °C. In the lamination process, at least two resin components are laminated together with the coating film to form a laminate; and In the heating and pressurizing process, the laminate is heated at a heating temperature H℃ below R℃ while being pressurized in the lamination direction.

2. The method for joining resin components according to claim 1, wherein, At least one of the at least two resin components is a transparent resin component.

3. The method for joining resin components according to claim 1, wherein, Both of the at least two resin components are transparent resin components.

4. The method for joining resin components according to any one of claims 1 to 3, wherein, The heating temperature H℃ in the heating and pressurizing process is below (R-20)℃.

5. The method for joining resin components according to any one of claims 1 to 3, wherein, Between the lamination process and the heating and pressurizing process, there is a preheating process in which the laminate is preheated at a temperature below (B+25)°C.

6. The method for joining resin components according to claim 4, wherein, Between the lamination process and the heating and pressurizing process, there is a preheating process in which the laminate is preheated at a temperature below (B+25)°C.

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