Graft polymer and article containing the same

Abstract

To provide a polymer having a molecular structure that can markedly modify surface properties resulting from surface modification treatment, and an article containing the polymer.SOLUTION: A graft polymer comprises a branched structure via urea bonds from carbon atoms of the main chain, wherein the graft polymer comprises a randomly branched structure via urea bonds from carbon atoms of the main chain, as shown in Formula (4), and / or, in a portion of the main chain, comprises a branched structure via urea bonds from both of any two adjacent carbon atoms, as shown in Formula (5).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to grafted polymers and articles containing the polymers. [Background technology]

[0002] In automotive parts, electronics parts, and various other fields, there is a demand for surface treatments that improve adhesion to adhesive layers and coating layers, and make resin surfaces hydrophilic, water repellent, lipophilic, and stain-resistant. For this reason, plasma treatment has been used to improve adhesion to adhesive layers and coating layers, and make resin surfaces hydrophilic and water repellent. However, there is a problem with hydrophilization in particular, where plasma treatment alone causes changes over time, and in some cases the effect of the treatment is reduced to about half of what it was immediately after treatment in just a few hours. Recently, there has also been an increasing demand for the treatment effect to be maintained and last longer.

[0003] Meanwhile, functional coating thin films are currently being used for various purposes. One of these is the self-assembled monolayer (hereinafter sometimes referred to as SAM layer). In one form of SAM layer, polar groups (hydrophilic groups) such as hydroxyl groups and carboxyl groups are added to the substrate surface, and metal alkoxide-based materials, organic silane-based materials, and organic phosphonic acid-based materials self-assemble as SAM materials to form a monolayer. In the case of metal alkoxide-based materials and organic silane-based materials, the products of the hydrolysis reaction accumulate through hydrogen bonds with the polar groups on the substrate surface, and are covalently bonded by a dehydration condensation reaction. In the case of organic phosphonic acid-based materials, salts are formed with the polar groups of basic or neutral oxides on the substrate surface, and are covalently bonded by a dehydration condensation reaction.

[0004] The methods for producing SAM layers can be broadly divided into wet processes and dry processes. The former is called the sol-gel method, and uses an acid or base catalyst in an alcohol-based organic solvent. An alcohol solution in which the metal alkoxide or alkoxy organic silane is dissolved and an alcohol solution in which water is dissolved are prepared separately, and a catalyst is dissolved in the aqueous solution. The hydrolysis reaction is promoted by mixing the two. The solution is then applied by dip coating, spray coating, or spin coating, and the dehydration condensation reaction proceeds by evaporating the solvent.

[0005] In contrast, the dry process is based on vacuum and discharge technologies and can form a SAM layer without using solvents or catalysts. Using a vacuum plasma device, hydrophilic groups such as hydroxyl and carboxyl groups are added to the substrate surface by plasma treatment with water, oxygen, etc., and then a gas-phase metal alkoxide material or an alkoxy organic silane material is supplied to proceed with the hydrolysis-dehydration-condensation reaction.

[0006] Patent Document 1 describes how a polyethylene terephthalate (PET) substrate is irradiated with a mixed gas plasma of tetramethoxysilane and oxygen using a high-frequency plasma device to generate a silicon dioxide film having hydroxyl groups on the surface, and then the PET substrate having the silicon dioxide film and octadecyltrimethoxysilane poured into a glass container are placed in a Teflon container, and the container is left in a 100°C oven for 5 hours to form a hydrophobic SAM layer.

[0007] Patent Document 2 describes a method in which a polyethylene terephthalate (PET) substrate is irradiated with oxygen gas plasma using a high-frequency plasma device to form irregularities on the surface of the PET substrate while simultaneously adding hydroxyl groups, which are adsorbing groups, and then irradiated with a mixed gas plasma of tetraethoxysilane and oxygen to form a hydrophilic SAM layer. However, the plasma treatment in which etching is performed to form irregularities on the PET substrate has the problem of accelerating deterioration of the substrate.

[0008] Patent Document 3 describes a SAM layer manufacturing apparatus that has a chamber with electrodes, introduces Si-H bonds to the surface while applying a direct current, and forms a SAM layer of a vinyl derivative. However, it describes that the plasma treatment as a pretreatment for the SAM layer formation step is performed in a separate device, which poses a problem in terms of the number of steps required for moving the sample substrate.

[0009] Patent Document 4 describes an apparatus for forming a SAM layer after performing remote processing using plasma from a high-frequency plasma source for the purpose of cleaning the surface of a sample substrate before forming a SAM layer on the sample substrate. However, since the remote plasma processing is used as a cleaning process, there are problems that the power of imparting hydrophilic groups such as hydroxyl groups to the substrate surface is weak, and the hydrophilic groups do not reach the desired density, and there are problems that there are limitations on the substrate material to which hydrophilic groups such as hydroxyl groups can be imparted to the substrate surface.

[0010] In order to solve the problems of the prior art described above, Patent Document 5 describes an apparatus and a method for forming a SAM layer in a consistent process without opening the vacuum chamber to the atmosphere, in a surface hydrophilization mode in which an evaporation source that imparts hydrophilic groups is supplied into a vacuum chamber, and the film formation surface of the substrate is modified by a plasma atmosphere formed by a plasma generator to hydrophilize the film formation surface, and a self-organization mode in which an evaporation source of a precursor material for the SAM layer is supplied to a substrate with a hydrophilized film formation surface, and a SAM layer is formed on the hydrophilized film formation surface, in a state in which an evaporation source that promotes hydrolysis of the precursor material for the SAM layer is supplied into the vacuum chamber while the vacuum chamber is in a vacuum.

[0011] Patent Document 6 describes a graft polymer in which a branch polymer containing a fluoroalkyl group is bonded to a trunk polymer via a bond having a -C(=O)NH- group, the bond having a -C(=O)NH- group being formed by a reaction between an active hydrogen group of a chain transfer agent constituting the branch polymer and an isocyanate group contained in a monomer constituting the trunk polymer, and the branch polymer is a fluorine-based polymer and the trunk polymer is a non-fluorine-based (hydrocarbon-based) polymer. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] JP 2003-276110 A [Patent Document 2] JP 2004-98350 A [Patent Document 3] International Publication No. 2017 / 069221 [Patent Document 4] Patent No. 6265496 [Patent Document 5] Patent Publication No. 2022-151518 [Patent Document 6] Patent No. 4815731 Summary of the Invention [Problem to be solved by the invention]

[0013] In recent years, in the field of surface treatment, there has been an increasing demand for surface modification such as water repellency, oil repellency, lipophilicity, hydrophilicity, and stain resistance. In particular, there has been an increasing demand for modifying the surfaces of materials that have traditionally been difficult to modify. However, although Patent Document 5 describes surface hydrophilization by adding OH groups, there is a problem in that a SAM cannot be formed on the surface of materials to which OH groups are difficult to add. In addition, the configuration described in Patent Document 6 discloses a graft polymer in which the trunk polymer is a hydrocarbon-based polymer and the branch polymer is a fluorine-based polymer via a bond having a -C(=O)NH- group, but does not disclose a polymer in which the trunk polymer is a fluorine-based polymer. In addition, the carbon adjacent to the carbon bonded to the branch polymer has a structure in which -CH2- derived from a vinyl group is present, so that a branched structure cannot be synthesized from the adjacent carbon, and there is a problem in that there is a limit to the graft density.

[0014] In recent years, there has been a strong demand for surface treatment of fluoropolymers such as polytetrafluoroethylene (PTFE). However, fluoropolymers have a low coefficient of friction, are non-adhesive, have poor adhesion to adhesives and pressure sensitive adhesives, and are difficult to disperse in powder form in other resins without a dispersant, and no technology has been found to solve these problems. Furthermore, even if hydrophilization is achieved using conventional plasma treatment, there is a change over time, so no technology has been found to maintain the treatment effect for a long period of time.

[0015] The object of the present invention is to provide a polymer having a molecular structure that can significantly modify the surface properties of materials that have traditionally been difficult to surface-modify, which is produced after a surface modification treatment in which a high-density SAM layer is formed by a dry process, and an article containing the polymer. [Means for solving the problem]

[0016] The graft polymer according to the present invention is a graft polymer having a branched structure via urea bonds from carbon atoms in the main chain, and is characterized in that the graft polymer has a branched structure randomly via urea bonds from carbon atoms in the main chain and / or has a branched structure via urea bonds from both of any two adjacent carbon atoms in a part of the main chain. The graft polymer according to the present invention is characterized in that it is a graft polymer having a branched structure from a carbon atom of the main chain via a urea bond, and the trunk polymer of the main chain has a fluorine-based polymer structure. The article according to the present invention is a graft polymer having a branched structure via urea bonds from carbon atoms in the main chain, and is characterized in that the branched structure is randomly branched via urea bonds from carbon atoms in the main chain and / or has a branched structure via urea bonds from both of any two adjacent carbon atoms in a part of the main chain. The article according to the present invention is characterized in that it contains a graft polymer having a branched structure via urea bonds from carbon atoms in the main chain, wherein the trunk polymer of the main chain contains a graft polymer having a fluorine-based polymer structure. Effect of the Invention

[0017] By synthesizing the graft polymer of the present invention at the interface with the atmosphere, the molecular structure at the interface can be made to have a long life because the urea bond is not hydrolyzed. In particular, by synthesizing a structure having a branched structure due to urea bonds randomly and / or on both of any two adjacent carbon atoms in the main chain on a surface that has been subjected to a surface modification treatment, a surface structure having a dense branched structure can be produced, and various surface properties such as water repellency, hydrophilicity, oil repellency, and oil affinity can be expressed. The graft polymer of the present invention is a polymer that is difficult to synthesize by ordinary chemical reactions, and since it has a branched structure formed from the carbon atoms in the main chain of the fluoropolymer and has a structure having a molecular chain of a certain degree of length, it is a fluoropolymer with unprecedented functionality. Furthermore, the article of the present invention has a SAM layer bonded by non-hydrolyzable urea bonds, and a molecular structure having a certain degree of molecular chains is present on the surface of the article, so that the surface modification effect can be maintained for a long time. Furthermore, the article of the present invention is not limited to plate-shaped films, but can also be surface-modified for powders, spherical objects, objects with irregularities, and objects with cavities. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing an overall configuration of a laminate manufacturing apparatus for carrying out laminate manufacturing according to an embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view of a vacuum chamber of a laminate manufacturing apparatus for carrying out laminate manufacturing according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described. Although the embodiment of the present invention will be described below, the present invention is not limited thereto.

[0020] The graft polymer of the present embodiment is a graft polymer having a branched structure via urea bonds from carbon atoms in the main chain. The branched portions of the graft polymer are randomly branched via urea bonds from carbon atoms in the main chain, and / or have a structure in which, in a part of the main chain, branches from both of any two adjacent carbon atoms via urea bonds.

[0021] The graft polymer of this embodiment forms a urea bond directly with a carbon atom in the main chain, forming a branched structure represented by the following formula (1).

[0022] [ka]

[0023] Regarding the formation of the urea bond, the surface of the base polymer is irradiated with plasma using ammonia (NH3) gas to provide NH2 groups, thereby generating a precursor of the graft polymer.

[0024] The graft polymer of this embodiment may be subjected to a multi-stage plasma treatment, or may be pretreated with a rare gas such as Ar, He, or Xe, and then activated with NH3. During the activation treatment, a mixed gas of the rare gas, H2O, or O2 may be used, but at least the activation treatment with NH3 is essential.

[0025] The plasma irradiation is a low-pressure high-frequency plasma treatment, which is a low-temperature plasma treatment. Therefore, the treatment can be performed under high electron density, and the surface of various materials can be modified. In this embodiment, amino groups are added by NH3 plasma, which makes it possible to introduce functional groups that are not possible by normal chemical reactions. In order to activate the surface of the material polymer by the plasma treatment, it is possible to generate a structure in which amino groups are added to both of any two adjacent carbon atoms randomly and / or in part of the main chain, as shown in the following formula (2).

[0026] [ka] Rf1 represents a hydrogen atom or a fluorine atom. Rf2 represents a hydrogen atom, a fluorine atom, a methyl group, a chlorine atom, a phenyl group, -CF3, or -OCF3.

[0027] To generate the urea bond, an isocyanate compound, which is a SAM precursor, is injected into a vacuum chamber, whereby a chemical reaction between the amino group and the isocyanate group, as shown in reaction formula (3) below, takes place, forming a urea bond.

[0028] [ka]

[0029] The isocyanate compound, which is the SAM precursor, is selected from compounds having a vapor pressure under atmospheric pressure to low pressure. For example, monoisocyanate compounds such as 2-(acryloyloxy)ethyl isocyanate, 2-(methacryloyloxy)ethyl isocyanate, 3-(triethoxysilyl)propyl isocyanate, butyl isocyanate, hexyl isocyanate, heptyl isocyanate, dodecyl isocyanate, octadecyl isocyanate, phenethyl isocyanate, benzyl isocyanate, 4-ethylphenyl isocyanate, 4-butylphenyl isocyanate, 4-methoxyphenyl isocyanate, 4-ethoxyphenyl isocyanate, 3,5-dimethylphenyl isocyanate, 4-(trifluoromethyl)phenyl isocyanate, 4-(trifluoromethoxy)phenyl isocyanate, and 3,5-bis(trifluoromethyl)phenyl isocyanate can be mentioned, but are not limited thereto.

[0030] Examples of diisocyanate compounds include hexamethylene diisocyanate, 1,4-phenylene diisocyanate, methylene diphenyl 4,4'-diisocyanate, 2,2-bis(4-isocyanatophenyl)hexafluoropropane, and the like. Examples of triisocyanate compounds include, but are not limited to, 1,3,5-tris(6-isocyanatohexyl)-1,3,5-triazinane-2,4,6-trione.

[0031] In the graft polymer of the present embodiment, the molecular structure of the SAM layer of the branched structure portion is Examples of such a situation include a situation in which the structure of the following formula (4) is randomly present in the polymer molecular chain present at the interface with the air, a situation in which the structure of the following formula (4) and the structure of the following formula (5) are randomly mixed, or a situation in which the structure of the following formula (5) is randomly present.

[0032] [ka] Rf3 represents a hydrogen atom, a fluorine atom, a methyl group, a chlorine atom, a phenyl group, -CF3, or -OCF3. [ka] Rf4 represents a hydrogen atom or a fluorine atom. Rf5 represents a hydrogen atom, a fluorine atom, a methyl group, a chlorine atom, a phenyl group, -CF3, or -OCF3.

[0033] In the article of this embodiment, examples of materials (substrates) to be surface-modified include polymers that are difficult to surface-treat with conventional plasma treatments, such as olefin polymers such as polypropylene (PP), polyethylene (PE), and polymethylpentene (TPX), cycloolefin (COP) polymers, and polyvinyl chloride (PVC) polymers.

[0034] In particular, fluoropolymers are representative of polymers that are difficult to treat by normal plasma treatment, such as polytetrafluoroethylene (PTFE; polytetrafluoroethlene), polychlorotrifluoroethylene (PCTFE; polychlorotrifluoroethlene), perfluoroalkoxyalkane (PFA; poly[tetrafluoroethylene-co-prefluoro(alkyl vinyl ether)]), perfluoroethylenepropene copolymer (FEP; fluorinated ethylene propylene copolymer), ethylenetetrafluoroethylenecopolymer (ETFE; ethylene tetrafluoroethylenecopolymer), and polyvinylidene fluoride (PVDF; poly(vinyliden difluoride)).

[0035] Furthermore, the material to be surface modified is not limited to polymers that are difficult to treat with normal plasma, but can be any general-purpose polymer such as ethylene terephthalate (PET), engineering plastics, or super engineering plastics, as long as it can be surface aminated. Furthermore, the form of the material (substrate) to be surface-treated may be in the form of a plate, film, powder, filler, thread, or the like, and may be anything that can be surface-modified.

[0036] In the article of this embodiment, the material (substrate) to be surface-treated is irradiated with plasma using NH3 gas, and the surface is activated so that amino groups are added to the entire surface of the substrate exposed to the plasma. A multi-stage plasma treatment may be performed, or a pretreatment may be performed using a rare gas such as Ar, He, or Xe, and then an activation treatment using NH3 is performed. During the activation treatment, a mixed gas of the rare gas, H2O, or O2 may be used, but at least an activation treatment using NH3 gas is essential.

[0037] The surface activated by the introduction of the amino group is exposed to an isocyanate compound (SAM precursor), which is the raw material of the SAM layer, in a low-pressure chamber, and the amino group reacts with the isocyanate group to generate a urea bond, forming a SAM layer. The tip of the SAM layer can be provided with an alkyl group, a fluorinated alkyl group, an aryl group, a silanol group, a (meth)acrylic group, an isocyanate group, or the like. In addition, when the polymerizable group is a silanol group, a (meth)acrylic group, an isocyanate group, or the like, it is possible to further bond the same or different molecules by chemical reaction. In that case, it is possible to introduce an alkyl group, a fluorinated alkyl group, an aryl group, a silanol group, a (meth)acrylic group, an isocyanate group, an epoxy group, a glycidyl ether group, a mercapto group, an amino group, a vinyl group, or the like, as the functional group at the tip.

[0038] Fig. 1 is a schematic diagram showing the overall configuration of a laminate manufacturing apparatus according to an embodiment, and Fig. 2 is a cross-sectional view of a vacuum chamber of the laminate manufacturing apparatus according to an embodiment.

[0039] The laminate manufacturing apparatus 1 according to this embodiment is an apparatus for forming a SAM layer on a film formation surface of a substrate.

[0040] In this embodiment, a substrate S having at least two surfaces is used as the substrate. The material constituting the substrate S is one exemplified as the material (base material) to be subjected to the surface treatment.

[0041] As shown in FIG. 1, the laminate manufacturing apparatus 1 has a vacuum chamber 2 that accommodates a substrate S, a lower electrode 3 that also serves as a sample stage for placing the substrate S in the vacuum chamber 2, and an upper electrode 4 that faces the lower electrode 3, and a plasma generation power supply 7 is connected to the lower electrode 3. In FIG. 1, the lower electrode 3 also serves as the sample stage, but the upper electrode 4 may also serve as the sample stage, or both the lower electrode 3 and the upper electrode 4 may also serve as the sample stage. In addition, the plasma generation power supply 7 can be a low-frequency power supply or a microwave power supply, but a high-frequency power supply is preferable, and a power supply with a frequency of 13.56 MHz is further preferable. In addition, a pressure gauge 5 that monitors the pressure in the vacuum chamber 2, an earth 6, and a vacuum pump 9 are connected to the vacuum chamber 2. In addition, the gas inlet 10 used for plasma processing, a bubbler 15 for a reactant material necessary for the plasma processing and the SAM layer film formation process, and a raw material chamber 18 for the SAM layer are connected by piping and introduced into the vacuum chamber 2.

[0042] Furthermore, as shown in FIG. 2, the vacuum chamber 2 in this embodiment has an upper chamber 27 and a lower chamber 28, and the lower chamber 28 has an O-ring 30.

[0043] In this embodiment, the upper chamber 27 and the lower chamber 28 are made of electrically grounded electrical conductors, and the entire inner wall surface of the vacuum chamber 2 is a ground potential surface whose potential is grounded. The electrical conductors constituting the upper chamber 27 and the lower chamber 28 are metallic materials made of transition metals such as copper, nickel, titanium, and the like, alloys of these metals, stainless steel, and high-melting point metals such as molybdenum and tungsten.

[0044] In this embodiment, a gas inlet 21 is provided at the top of the upper chamber 27, and a gas inlet 10 used for plasma treatment, a bubbler 15 for reactant substances required for the plasma treatment and the SAM layer deposition process or for the raw materials for the SAM layer, and piping connected from the raw material chamber 18 for the SAM layer are connected to the gas inlet 21.

[0045] In this embodiment, the lower electrode 3, which also serves as a sample stage, is composed of a current introduction terminal 22 and an electrode stage 23, and insulating members 26 are arranged around the current introduction terminal 22 and under the electrode stage 23. The current introduction terminal 22 is connected to a high-frequency power supply 7. The upper electrode 4 facing the lower electrode 3 has a structure that also serves as a gas shower plate 24.

[0046] In this embodiment, the lower chamber 28 has a structure in which an earth ring 25 is provided in a form surrounding the electrode stage 23. It is preferable that the difference in height between the electrode stage 23 and the earth ring 25 is approximately 0 mm, and it is preferable that the earth ring 25 is higher than the electrode stage 23. The earth ring 25 is formed so that the gap between it and the electrode stage 23 is 1 mm or more and 5 mm or less. By forming such a gap, it is possible to control the gas flow and expand the uniform plasma region as much as possible.

[0047] If the distance between the earth ring 25 and the electrode stage 23 is less than 1 mm, the distance is too narrow to draw gas sufficiently when the vacuum pump is used, and abnormal discharge occurs, making it impossible to generate the desired plasma. Also, if the distance between the earth ring 25 and the electrode stage 23 is greater than 5 mm, abnormal discharge occurs between the electrode stage 23 and the earth ring 25, making it impossible to generate the desired uniform plasma. Furthermore, lower chamber 28 has vacuum exhaust port 29 between current introduction terminal 22 and earth ring 25, and is connected to vacuum pump 9, with the degree of vacuum being adjusted by exhaust flow rate control valve 8. Therefore, by using the device of this embodiment, it is possible to satisfactorily carry out hydrophilization treatment by plasma treatment in the pretreatment step of forming a SAM layer.

[0048] In this embodiment, the gas used for plasma treatment is introduced from a gas inlet 10 and is connected to three gas introduction pipes: a bubbler 15 for reactant substances required for the plasma treatment and the SAM layer deposition process or for the raw materials for the SAM layer, and a raw material chamber 18 for the SAM layer. The gas introduction pipes are surrounded by a heat insulating material (not shown) or a heater (not shown) to prevent the gas from liquefying.

[0049] In this embodiment, the gas used for the plasma processing introduced from the gas inlet 10 is supplied from a gas cylinder (not shown) and introduced into the vacuum chamber 2 via a flow rate control valve / mass flow controller 11. The gas used for the plasma processing is selected from gases that impart amino groups (NH2 groups) to the surface of the sample S. For example, ammonia (NH3) can be used. There is no limitation as long as the gas imparts NH2 to the surface.

[0050] When the gas used for plasma processing is supplied to the vacuum chamber 2, the degree of vacuum in the vacuum chamber 2 is controlled by the exhaust flow control valve 8 and the vacuum pump 9, and by discharging between the lower electrode 3 and the upper electrode 4, the above gas functions as a plasma generating gas, and plasma activation processing is performed on the sample S.

[0051] In this embodiment, the bubbler 15 into which the reactant material required for the plasma treatment or the SAM layer deposition process or the vapor source 17 which is the raw material for the SAM layer is injected is equipped with a mantle heater 16, and may generate vapor of the vapor source 17 which is the reactant material required for the plasma treatment or the SAM layer deposition process by heating, and may be supplied to the vacuum chamber 2. The bubbler 15 is used for gases which are the raw material compounds for the SAM layer and which should be injected while bubbling the gas. The bubbler 15 is connected to a pipe through which a carrier gas is supplied from an inlet 12 for a carrier gas for carrying the vapor of the vapor source 17 via a flow rate control valve / mass flow controller 13, and a pipe having a bypass valve 14 through which a carrier gas which can be mixed with the vapor from the bubbler without passing through the bubbler 15 is configured. If the carrier gas is not required, the carrier gas does not need to be flowed. In the case of a raw material for the SAM layer which does not need to be bubbling, a gas different from the gas inlet 10 may be injected from the carrier gas inlet 12 without using the bubbler 15.

[0052] As the vapor source 17, which is a reactant material necessary for the plasma treatment and the deposition process of the SAM layer, an evaporation source that imparts NH2 groups to the surface of the sample S is selected. For example, aqueous ammonia is exemplified.

[0053] When a vapor source 17, which is a reactant material necessary for the plasma treatment and SAM layer deposition process, is supplied to the vacuum chamber 2, the above-mentioned NH3 gas functions as a plasma generating gas by discharging between the lower electrode 3 and the upper electrode 4, and NH2 groups are added to the surface of the sample S.

[0054] In the SAM layer formation process immediately afterwards, the low pressure inside the chamber and the residual components of the plasma during discharge promote the chemical reaction between the raw material of the SAM precursor and NH2 on the surface of the sample S. The raw material of the SAM precursor is continuously injected into the vacuum chamber 2 without breaking the vacuum by using the exhaust flow control valve 8 and the vacuum pump 9, but this can be done either during or after the discharge has stopped.

[0055] In this embodiment, the raw material chamber 18 for the SAM layer, into which a vapor source 20 of the SAM precursor is injected, is equipped with a mantle heater 19, and by heating, vapor is generated in the raw material chamber 18 for the SAM layer and supplied to the vacuum chamber 2.

[0056] An isocyanate compound of the SAM precursor having a vapor pressure from atmospheric pressure to low pressure is selected for the SAM layer raw material chamber 18 into which the vapor source 20 of the SAM precursor is injected and for the bubbler 15 into which the vapor source 17 of the raw material of the SAM layer is injected. Examples of monoisocyanate compounds include, but are not limited to, 2-(acryloyloxy)ethyl isocyanate, 2-(methacryloyloxy)ethyl isocyanate, 3-(triethoxysilyl)propyl isocyanate, butyl isocyanate, hexyl isocyanate, heptyl isocyanate, dodecyl isocyanate, octadecyl isocyanate, phenethyl isocyanate, benzyl isocyanate, 4-ethylphenyl isocyanate, 4-butylphenyl isocyanate, 4-methoxyphenyl isocyanate, 4-ethoxyphenyl isocyanate, 3,5-dimethylphenyl isocyanate, 4-(trifluoromethyl)phenyl isocyanate, 4-(trifluoromethoxy)phenyl isocyanate, and 3,5-bis(trifluoromethyl)phenyl isocyanate.

[0057] In the SAM layer formation process, the low pressure inside the chamber and residual components of the plasma during discharge promote the chemical reaction between the raw material of the SAM precursor and the NH2 group on the surface of the sample S. The raw material of the SAM precursor is continuously injected into the vacuum chamber 2 without breaking the vacuum using the exhaust flow control valve 8 and the vacuum pump 9. The vapor source 20 of the SAM precursor material can be supplied to the vacuum chamber 2 either during or after discharge has stopped between the lower electrode 3 and the upper electrode 4.

[0058] The surface that has been activated by the introduction of NH2 groups is exposed to an isocyanate compound (SAM precursor), which is the raw material for the SAM layer, in a low-pressure chamber, and the amino groups and isocyanate groups react to produce urea bonds and form a SAM layer. EXAMPLES

[0059] (Comparative Example) In the laminate manufacturing apparatus 1 shown in Figures 1 and 2, a PTFE substrate S as a comparative sample was placed on the lower electrode 3 of a vacuum chamber 2, covered with an upper chamber 27, and placed so that the upper electrode 4 was parallel to and facing the lower electrode 3.

[0060] A process of providing OH groups to the surface of the comparative sample was carried out. The atmospheric pressure in the vacuum chamber 2 was once reduced to 5 to 10 Pa. Then, a bubbler 15 into which water (H2O) was injected as a vapor source 17, which is a reactant substance required for plasma treatment and the film formation process of the SAM layer, was heated to 70°C by a mantle heater 16, and water vapor gas was introduced into the vacuum chamber 2 so that the atmospheric pressure in the vacuum chamber 2 became 100 Pa. A 13.56 MHz high-frequency power source was used as the plasma generation power source 7, and water vapor plasma irradiation was carried out for 3 minutes with a power of 200 W.

[0061] The raw material chamber 18 for the SAM layer, into which 5 cc of 3-(acryloxy)propyltrimethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) was injected as the vapor source 20 of the SAM precursor material, was heated to 80° C. using a mantle heater 19. After plasma irradiation was completed, the valve of the bubbler 15 was closed, and then, without opening the vacuum chamber 2 to the atmosphere, the valve of the raw material chamber 18 for the SAM layer was opened to introduce 3-(acryloxy)propyltrimethoxysilane into the vacuum chamber 2, and the PTFE substrate of sample S was exposed to 3-(acryloxy)propyltrimethoxysilane vapor for 20 minutes, thereby forming a SAM layer on the sample.

[0062] After closing the valve of the raw material chamber 18 for the SAM layer, the vacuum chamber 2 was opened to the atmosphere, and the ultraviolet (UV) curable acrylic resin "Padico UV-LED Coating Resin Hoshi no Shizuku Gloss" was applied to the sample substrate S, and it was confirmed that it was repelled and not applied. Therefore, it was confirmed that a silane coupling agent SAM layer made of 3-(acryloxy)propyltrimethoxysilane was not formed on the PTFE substrate sample S.

[0063] Example 1 In the laminate manufacturing apparatus 1 shown in Figures 1 and 2, a PTFE substrate serving as sample S was placed on a lower electrode 3 in a chamber 2, which was covered with an upper chamber 27, and the upper electrode 4 was placed parallel to and facing the lower electrode 3.

[0064] A process of providing NH2 groups to the surface of sample S was carried out in the same manner as in the comparative example. That is, the atmospheric pressure in chamber 2 was once reduced to 5 to 10 Pa. Then, as a plasma treatment, NH3 gas was introduced from gas inlet 10 into chamber 2 so that the atmospheric pressure in chamber 2 became 130 Pa. A 13.56 MHz high-frequency power source was used as plasma generation power source 7, and NH3 plasma irradiation was carried out for 1 minute with a power of 200 W.

[0065] The raw material chamber 18 for the SAM layer, into which 5 cc of 2-(acryloyloxy)ethyl isocyanate was injected as the vapor source 20 of the SAM precursor material, was heated to 70° C. using a mantle heater 19. After plasma irradiation was completed, the valve of the gas inlet 10 was closed, and then, without opening the vacuum chamber 2 to the atmosphere, the valve of the raw material chamber 18 for the SAM layer was opened to introduce 2-(acryloyloxy)ethyl isocyanate into the vacuum chamber 2, and the PTFE substrate of sample S was exposed to 2-(acryloyloxy)ethyl isocyanate vapor for 20 minutes, thereby forming a SAM layer on the sample.

[0066] After closing the valve of the raw material chamber 18 for the SAM layer, the vacuum chamber 2 was opened to the atmosphere, and the ultraviolet (UV) curable acrylic resin "Padico UV-LED Coating Resin Hoshi no Shizuku Gloss" was applied to the sample substrate S, which was wet enough to be applied, and UV was irradiated. An acrylic coating was then formed on the PTFE substrate, and it was confirmed that the coating was firmly adhered without cracking or peeling.

[0067] Example 2 In the laminate manufacturing apparatus 1 shown in Figures 1 and 2, a PTFE substrate serving as sample S was placed on a lower electrode 3 in a chamber 2, which was covered with an upper chamber 27, and the upper electrode 4 was placed parallel to and facing the lower electrode 3.

[0068] A process of providing NH2 groups to the surface of sample S was carried out in the same manner as in the comparative example. That is, the atmospheric pressure in chamber 2 was once reduced to 5 to 10 Pa. Then, as a plasma treatment, NH3 gas was introduced from gas inlet 10 into chamber 2 so that the atmospheric pressure in chamber 2 became 130 Pa. A 13.56 MHz high-frequency power source was used as plasma generation power source 7, and NH3 plasma irradiation was carried out for 1 minute with a power of 200 W.

[0069] The raw material chamber 18 for the SAM layer, into which 5 cc of 2-phenylethyl isocyanate was injected as the vapor source 20 of the SAM precursor material, was heated to 70° C. using a mantle heater 19. After plasma irradiation was completed, the valve of the gas inlet 10 was closed, and then, without opening the vacuum chamber 2 to the atmosphere, the valve of the raw material chamber 18 for the SAM layer was opened to introduce 2-phenylethyl isocyanate into the vacuum chamber 2, and the PTFE substrate of sample S was exposed to 2-phenylethyl isocyanate vapor for 20 minutes, thereby forming a SAM layer on the sample.

[0070] After closing the valve of the raw material chamber 18 for the SAM layer, the vacuum chamber 2 was opened to the atmosphere, and a benzene solution of polystyrene was applied onto the sample substrate S, which allowed for wet application. After that, the benzene solvent was evaporated and the substrate was dried, forming a polystyrene coating film on the PTFE sample substrate S, and it was confirmed that the coating film was firmly adhered without cracking or peeling. Therefore, the surface of the PTFE sample substrate S was depolarized with 2-phenylethyl isocyanate.

[0071] It was also confirmed that the surface characteristics of the non-polar surface-modified sample substrate S did not change even when the solvent benzene was poured onto the surface-modified sample substrate S. Furthermore, the contact angle with water was measured to be 96°, confirming that the sample was hydrophobic. The contact angle with water of the untreated PTFE sample S was 120°, and the contact angle with water of the PTFE sample S to which NH2 groups had been introduced by ammonia plasma was 8° immediately after plasma exposure. Therefore, it was confirmed that 2-phenylethyl isocyanate had reacted firmly with the PTFE polymer derivative to which NH2 groups had been added, and was bonded by urea bonds.

[0072] From the above results, it was confirmed that the graft polymer of the present invention is a fluoropolymer having an NH2 group introduced into the main chain, which has reacted with a SAM precursor compound having an isocyanate group, and has a branched structure due to urea bonds.

[0073] The present invention has been described above using preferred embodiments, but these descriptions are not limiting and various modifications are possible. For example, the above embodiment was carried out using a PTFE sample substrate S and a parallel plate type vacuum plasma device, but a fluoropolymer sample powder and a rotating drum type vacuum plasma device may be used to form a SAM layer on the powder surface. In addition, the present invention may be carried out not only on fluoropolymers and powders but also on various types of articles other than polyolefin materials and powders. [Explanation of symbols]

[0074] 1 Laminate manufacturing equipment 2. Vacuum chamber 3 Lower electrode (stage) 4 Upper electrode 5 Pressure Gauges 6. Earth 7. Power supply for plasma generation 8 Exhaust flow control valve 9. Vacuum Pump 10 Gas inlet 11, 13 Flow control valve / Mass flow controller 12 Carrier gas inlet 14 Bypass valve 15 Bubbler for reactant materials required for plasma processing and SAM film deposition processes 16, 19 Mantle heater 17 Vapor sources that are reactant materials necessary for plasma processing and SAM film deposition processes 18. SAM film raw material chamber 20 Vapor source of SAM precursor material 21 Gas inlet 22 Current introduction terminal 23 Electrode Stage 24 Gas shower plate 25 Earth Ring 26 Insulating materials 27 Upper Chamber 28 Lower Chamber 29 Vacuum exhaust port 30 O-ring

Claims

1. A graft polymer having a branched structure via a urea bond from a carbon atom of a main chain, It has a randomly branched structure via urea bonds from the carbon atoms of the main chain. and / or has a branched structure via urea bonds from both of any two adjacent carbon atoms in a part of the main chain; A graft polymer characterized by:

2. A graft polymer having a branched structure from a carbon atom of a main chain via a urea bond, wherein the trunk polymer of the main chain is a fluorine-based polymer.

3. The main chain trunk polymer is a fluorine-based polymer, It has a randomly branched structure via urea bonds from the carbon atoms of the main chain. and / or has a branched structure via urea bonds from both of any two adjacent carbon atoms in a part of the main chain; The graft polymer according to claim 1 or 2.

4. An article comprising the graft polymer of claim 1.

5. An article comprising the graft polymer according to claim 2.

6. 6. An article according to claim 4 or 5, comprising the graft polymer according to claim 3.

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