JPH10182851A - Adhesion of polymer surface without using adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To firmly adhere two polymer substrates, such as films or fibers, to each other without using an adhesive by activating the surface of a substrate e.g. with a plasma, then immersing the substrate in a soln. or emulsion contg. a functional monomer, and subjecting the resultant coated item to heat treatment or the exposure to near-ultraviolet rays to cause the graft copolymn. on the surface. SOLUTION: This adhesion method can be applied to all kinds of polymer films, e.g. a film of a polyolefin, a polyester, a fluorohydrocarbon polymer, or a thermosetting resin. The monomer for the surface graft copolymn. is pref. a hydrophilic vinyl monomer having a polar, cationic, anionic, amphoteric, or electrolytically functional group and is selected from among acrylic acid compds., acrylamide, acrylates, and epoxy monomers. Pref. a polymer films or fibers are preactivated with a plasma, ozone, etc. The adhesion between two polymers treated as above without using an adhesive is performed by bringing them into direct contact with each other in the presence of water or a solvent for the graft polymer and drying them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to an adhesive (or adhesive) between two polymer films; a polymer film and a polymer fiber; and a polymer film or fiber and a polymer matrix. Not) about bonding. In particular, adhesion without using an adhesive is performed by modifying a polymer film and a polymer fiber by surface graft copolymerization using a functional monomer.

[0002]

BACKGROUND OF THE INVENTION Frequently, selected polymers have surface properties that are less than optimal for the intended application. This is especially true in the case of bonding of polymer surfaces. In order to improve this, challenges regarding surface chemical modification have been widely conducted. These are described in detail, for example, in the following literature (S. Wu, Polymer Interface).
ces and Adhesion, Dekker, N
ew York (1982); Ikada and
Y. Uyama, Lubricating Poly
mer Surfaces, Technologies P
ub. Co. , Lancaster, PA (199
3); L. Mittal, (Ed) Polymer
Surface Modification: Rel
Evanceto Adhesion, VSP, Zei
st, The Netherlands (1995);
L. S. Penn and H.S. Wang, Polym
er for Advanced Technology
ies, 5,809-817 (1994);
T. Kang, K .; G. FIG. Neoh, K .; L. Tan,
F. C. Loh and D.S. J. Liaw, Poly
mers for Advanced Technology
ogies, 5, 837-842 (1994)).

[0003] Various techniques are useful for chemical modification of polymer surfaces to improve adhesion. These techniques include acid etching, X-ray irradiation, ultraviolet irradiation, electron beam impact, ozone treatment, corona discharge and plasma treatment. The most recent technologies are described in detail, for example, in the following literature (M.
Strobel, C .; S. Lyons and K.S.
L. Mittal, (Eds.) Plasma Sur
face Modification of Poly
mers: Relevance to Adhesio
n, VSP, Zeist, The Netherlands
nds (1994)). Various polar and functional groups are formed on the polymer surface as a result of these treatments. One of the major drawbacks of these treatments is that the physicochemical properties of the modified polymer surface, including the surface composition, are time dependent. Reorientation of the linkage groups or polar groups in the surface region results in a gradual decrease in surface reactivity. further,
Since the polar groups and functional groups generated on the polymer surface by these methods are generally essentially small molecules or generally limited to a few surface molecular layers, the adhesion between the two modified polymer surfaces is external. Promoted only by the presence of the adhesive applied from the

Many patent documents claim surface modification of a polymer in order to enhance the adhesive strength. No similar claims or reports were found in a patent search by the inventor for non-adhesive or self-adhesive polymer films or fibers based on surface graft copolymerization. Some examples and interesting claims are summarized below.

[0005] In JP-A-7-101,017 (April 18, 1995), a simple adhesive resin layer is prepared to make a polyester film useful for magnetic recording media. JP-A-7-216,319 (April 15, 1995)
On the other hand, a self-adhesive sheet having an adhesive layer containing an elastomer, a tackifier resin, a softening agent and an incompatible polymer compound is claimed in JP-A-2001-209.

German Patent DE 4,410,558 A1
In (September 28, 1995) a malleable, multilayer, self-adhesive screen sheet or strip carrying conductors; an electromagnetic field or radiation screen pipe used as a conduit is prepared.

Japanese Patent Application Laid-Open No. 7-216,322 (August 15, 1995) manufactures a self-adhesive, non-cured rubber sheet or tape by laminating a self-adhesive, non-cured rubber on a surface material. If so, the surface material is temporarily bonded to release paper, then self-adhesive rubber is laminated to it, and the laminate is wound into a roll.

In Japanese Patent Application Laid-Open No. 7-216,315 (August 15, 1995), a self-adhesive film that leaves no residue on a substrate comprises a thin metal layer on a support film made of, for example, polyolefin. It is prepared by forming a self-adhesive layer on the other end of the support film.

Japanese Patent Application Laid-Open No. 7-188,634 (July 25, 1995) discloses a one-pack curable epoxy for self-adhesive tape containing epoxy resin, ketimine, modified silicone resin, and catalyst for modifying silicone resin. Resin and self-adhesive are prepared.

The international application WO 9,411,421 (19)
May 26, 1994) and European Patent EP 667,87.
No. 9, August 23, 1995, modification of the polymer surface by coating with particles changed the surface top layer to a swellable or semi-dissolved state without the use of an adhesive, and simultaneously or subsequently It is carried out by coating with.

European Patent EP 358,519A (1)
March 24, 990); JP-A-2-073,828 (1)
March 13, 990); JP-A-2-245033 (1)
September 28, 990); U.S. Pat. 5,049,6
26 (September 17, 1991); European Patent EP3
58, 519A3 (March 18, 1992); and U.S. Pat. 5,300,548 (April 5, 1994
A) a graft copolymer comprising a monomer copolymer from an unsaturated carboxylic acid ester, a vinyl ester, ethylene and a polyamide oligomer having a primary amino group at one end of a molecule grafted to CO and a stock. Has been charged.

In JP-A-4-370,107 (December 22, 1992), it has been found that a modified copolyester does not form an aqueous group in a medium in the presence of a copolyester not forming a substituent of a sulfonic acid derivative. Obtained by polymerizing a saturated monomer. Also claimed is a simple adhesive polyester film obtained by applying an aqueous solution of the modified copolymer to at least one side of the polyester film.

German Patent DE 3,602,800 A (1
European Patent EP204, December 11, 986);
943A (December 17, 1986); U.S. Pat.
No. 4,740,562 (April 26, 1988); and DE 3,602,800 C, the surface of polyvinylidene fluoride articles is treated with dehydrofluorination, bases, solvents or swelling agents and homogenizing agents. It is denatured by etching to improve adhesion and hydrophilicity.

[0014]

It is an object of the present invention to provide a method for imparting adhesive-independent adhesive properties between (the surface of) two contact polymer surfaces.

It is another object of the present invention to provide a method for adhering two polymer films in the absence of an adhesive. Adhesion in the form of lap shear strength between two polymer thin films can easily exceed the yield strength of the polymer film.

It is a further object of the present invention to provide a method for adhering a polymer film and a polymer fiber in the absence of an adhesive.

[0017]

SUMMARY OF THE INVENTION According to the present invention, adhesive-free bonding includes all polymer films, such as films of polyolefins, polyesters, hydrocarbons and fluoro (fluor) polymers, electroactive (conductive). ) Or a conjugated polymer film and a thermosetting film. The preferred applications and benefits of the present invention are obtained with flexible, thermoplastic films.

Another benefit of the present invention is that the adhesive properties without the adhesive are not limited to two similar or identical polymer substrates, such as the combination of a fluoropolymer film and a polyolefin film. Between polymer films with very different physicochemical properties and compositions, such as between

These and other objects and benefits of the present invention are obtained by first providing a method for modifying the surface of a polymer film or fiber. A preferred method is a thermal or near UV induced surface graft copolymerization of the preactivated substrate surface using a functional monomer.

The polymer substrate is preactivated by treatment with plasma, ozone, corona discharge, ultraviolet irradiation, or by means of a peroxide or hydroperoxide (-OOH) species formed on the surface of the polymer substrate. Is preferred,
Thereafter, the preactivated polymer substrate is immersed in an aqueous solution, organic solution or emulsion containing a functional monomer, and the resulting coating (mixture) is heated or near ultraviolet (near ultraviolet).
UV) irradiation to cause surface graft copolymerization.

It is an object and benefit of the present invention that two surface-modified polymer films or surface-modified films and fibers are loaded into intimate contact with each other in the presence of a small amount of water or a solvent for the graft polymer. It is realized when. Boundary bond strength is fully exhibited when the solvent dries or evaporates.

It is an object and advantage of the present invention that the graft polymer chains from two wrapped films or films and fibers will diffuse, entangle, interact, disperse, disperse, interact at the interface. Ionic interactions,
Achieved when subjected to electrostatic interactions, H (hydrogen) -bonds and / or covalent bonds. Also, in the presence of sufficient ionic or electrostatic interaction, considerable adhesive strength is observed between lap joints of aqueous media.

The monomer for the surface graft copolymerization is selected from vinyl monomers which easily undergo radical initiation polymerization. The monomer is preferably selected from those having a polar group, a cationic group, an anionic group, an amphoteric group or an electrolyte functional group.

More specifically, such a functional monomer is
It is preferable to be selected from a water-soluble monomer or a hydrophilic monomer. With this choice, the objects and benefits of the present invention are achieved by using water as a solvent for surface modification and subsequent interfacial adhesion, thereby resulting in the expensive and environmentally hazardous typically found in commercial adhesives. No organic solvent is required.

The monomers used herein include acrylic acid-based monomers, acrylamide, acrylate, sulfonic acid-containing monomers, electrolyte monomers, amphoteric monomers, glycidyl groups or epoxy compounds. Any one selected from the group consisting of a monomer containing a group and a monomer containing an amine may be used.

The polymer base film used here is:
Polyolefins, hydrocarbon polymers, such as, but not limited to, high density polyethylene, low density polyethylene, polystyrene, polypropylene, polycarbonate and the like; polyester films, such as
Including but not limited to poly (ethylene terephthalate); fluoropolymers such as, but not limited to, polytetrafluoroethylene, poly (vinylidene fluoride), and copolymers thereof. It may be selected from coalescence. Thin thermoset films or thin polymer films with thermoset properties include, but are not limited to, epoxy films,
A polyimide film may be used. Conjugated polymer films or electroactivated polymer films are based on, for example, but not limited to, films of aniline, pyrrole, thiophene, substituted acetylene and phenylene vinylene polymers, derivatives and analogs thereof. It may be used as a material.

The objects and benefits of the present invention are enhanced when the graft polymer chains at the wrap interface exhibit ionic, polar interactions, H-bonds and / or bonds via metal chelates. For a substrate film comprising a surface-grafted anionic polymer or a polymer having anionic groups, such as carboxyl groups, the boundary adhesion may be divalent or polyvalent salts, such as, but not limited to, Zn
It is promoted by introducing salts and Cd salts. The presence of a metal ion induces an ionic bond with a binding energy close to the energy of a covalent bond. Ionic bonding results in shorter drying times and faster bond strength.

The objects and benefits of the present invention are also substantially enhanced when the graft polymer chains at the wrap interface are covalently linked and crosslinked. More specifically, one substrate surface of the lap joint surface is graft copolymerized with an epoxy group-containing monomer, such as, but not limited to, glycidyl methacrylate, while the corresponding (opposite) The substrate surface has a hydroxyl group-containing monomer or an amine-containing monomer, such as, but not limited to, N 2
When graft copolymerization is performed using-(hydroxymethyl) acrylamide, a curing reaction between an epoxy functional group and a hydroxyl group or an amine group causes a covalent bond or cross-linking to interface with high adhesive strength.

The objects and benefits of the present invention can be extended to methods of enhancing the coupling between a polymer film or polymer fibers and a polymer matrix in making a film or fiber reinforced resin composite. Here, the production method includes, before impregnation of the polymer film or polymer fiber with the liquid resin, a first functional group capable of undergoing radical-initiated polymerization and a second function capable of reacting with a curing agent in the liquid resin. Modification of a polymer film or polymer fiber by surface graft copolymerization using a functional monomer having a functional group is included. Preferably, the liquid resin is an epoxy resin, the second functional group is an epoxide, and the curing agent is a secondary, tertiary or quaternary amine. The functional monomer is glycidyl methacrylate, allyl glycidyl ether or glycidyl functional aromatic monomer; the polymer fiber is aramid fiber, aromatic nylon fiber, ultra-high module (elastic) polyethylene fiber, carbon fiber or graphite fiber. You may.

The polymer film or fiber may be surface grafted by plasma, ozone, corona discharge, ultraviolet radiation or by means such that peroxide or hydroperoxide species are formed on the surface of the polymer film or fiber. Pre-activated before polymerization, then
The coating is immersed in an aqueous solution, organic solution or emulsion containing a functional monomer, and the resulting coating is treated with heat or near-ultraviolet radiation to cause surface graft copolymerization.

Therefore, the invention is specified as follows.

According to the present invention, a) the surface of the first polymer substrate is
Modified by surface graft copolymerization with a first functional monomer capable of undergoing radical-initiated polymerization; b) surface grafting the surface of the second polymer substrate with a second functional monomer capable of undergoing radical-initiated polymerization C) contacting the modified surface of the first polymer substrate with the modified surface of the second polymer substrate in the presence of a liquid medium; Maintaining the contact until dry.

Here, the first polymer base material is formed of the first polymer base material.
Pre-activating the polymer substrate by plasma, ozone, corona discharge, ultraviolet irradiation or by means of forming a peroxide or hydroperoxide species on the surface of the first polymer substrate prior to surface graft copolymerization in step a) Preferably, the second polymer substrate is
Pre-activating the polymer substrate prior to surface graft copolymerization in step b) by plasma, ozone, corona discharge, UV irradiation or by means of forming a peroxide or hydroperoxide species on the surface of the second polymer substrate Is preferably performed.

Further, the first polymer substrate is immersed in an aqueous solution, an organic solution or an emulsion containing the first functional monomer, and the obtained coating is treated with heat or near-ultraviolet light to thereby form the first polymer substrate. Preferably, surface graft copolymerization is caused, the second polymer substrate is immersed in an aqueous solution, organic solution or emulsion containing the second functional monomer, and the resulting coating is heated or near ultraviolet light. It is preferable to carry out treatment by irradiation to cause the surface graft copolymerization.

Further, the first polymer substrate is preferably in the form of a film, and the second polymer substrate is preferably in the form of a film or a fiber.

Preferably, the first polymer substrate and the second polymer substrate are each independently selected from polyolefins and hydrocarbon polymers, and the polyolefin is a high-density polyethylene, a low-density polyethylene or More preferably, it is polypropylene, and the hydrocarbon polymer is polystyrene or polycarbonate.

Further, it is preferable that the first polymer substrate and the second polymer substrate are each independently a fluoropolymer or a halogen-containing polymer, and the fluoropolymer is polytetrafluoroethylene; Copolymer of fluoroethylene and hexafluoropropylene; copolymer of tetrafluoroethylene and perfluoro (propyl vinyl ether); copolymer of tetrafluoroethylene and perfluoro 2,2-dimethyl-1,3-dioxide Poly (vinyl fluoride); poly (vinylidene fluoride); or vinyl fluoride / vinylidene fluoride copolymer; and the halogen-containing polymer is a copolymer of tetrafluoroethylene and vinyl chloride; Fluoroethylene; vinylidene fluoride / hexafluoroethylene copolymer; poly (vinyl chloride) Le) or particularly preferably poly (vinylidene chloride).

The first polymer substrate and the second polymer substrate are preferably each independently polyester, and the polyester is particularly preferably poly (ethylene terephthalate).

Further, it is preferable that the first polymer base and the second polymer base are each independently a thermosetting material, and the thermosetting material is an epoxy polymer, polyimide, polyurethane or Particularly preferred is a phenolic polymer.

The first polymer base and the second polymer base are each independently an electroactive conjugated polymer, and the electroactive conjugated polymer is defined in claim 2 before surface graft copolymerization. Preferably do not undergo the pre-activation,
The electroactive conjugated polymer is particularly preferably a polymer of aniline, pyrrole, thiophene or acetylene.

Further, the first functional monomer and the second functional monomer
It is preferable that the functional monomers are each independently a hydrophilic vinyl monomer, and the hydrophilic vinyl monomer is a monomer based on acrylic acid (where the monomer is
(Meaning (meth) acrylic acid, (meth) acrylate), acrylamide, sulfonic acid-containing monomer or acrylate is particularly preferred.

Further, the first functional monomer and the second functional monomer are each independently selected from the group consisting of an electrolyte monomer, a zwitterionic monomer and an amphoteric monomer. Preferably, the first functional monomer and the second functional monomer are each independently dimethyl
Sulphate quaternised dimethylaminoethyl methacrylate _{(DMAEM.C 2 H 6 SO 4)} , 2- acylamino-2-methyl - propane sulfonate, 3
-Dimethyl (methacryloylethyl) ammonium
Particularly preferred is propane sulfonate (DMAPS) or 3-dimethyl (acryloyloxyethyl) ammonium propane sulfonate (DAAPS).

Further, the first functional monomer is preferably an epoxy-containing monomer, and the second functional monomer is preferably a monomer having epoxy curability. Is glycidyl methacrylate, allyl glycidyl ether or a glycidyl functional aromatic monomer, and the epoxy-curable monomer is particularly preferably N- (hydroxymethyl) acrylamide or N-butoxymethyl acrylamide.

Preferably, the first functional monomer and the second functional monomer are hydrophilic monomers, and the first functional monomer and the second polymer substrate Each is modified with a graft hydrophilic polymer, a graft anion polymer, a graft cationic polymer, a graft polyelectrolyte, a zwitterionic polymer or a graft amphoteric polymer, or the first polymer substrate is modified with a graft cationic polymer. Further, the second polymer substrate is modified with a graft anionic polymer, or the first polymer substrate is modified with a graft amphoteric polymer, while the second polymer substrate is a graft cationic polymer or It is particularly preferred that it be modified with any of the grafted anionic polymers.

Further, the liquid medium is preferably water or an organic solvent for an epoxy resin.

Further, the present invention relates to a method for preparing a polymer film or polymer fiber, comprising the steps of: impregnating the polymer film or polymer fiber with a liquid resin before impregnating the polymer film or polymer fiber with a liquid resin; When producing a film or a fiber-reinforced resin composite characterized by being modified by surface graft copolymerization using a functional monomer having a second functional group capable of reacting with a curing agent contained in a resin A method for enhancing the coupling between a resin film or polymer fibers and a polymer matrix.

Here, it is preferable that the liquid resin is an epoxy resin, the second functional group is an epoxy group, and the curing agent is a secondary, tertiary or quaternary amine.

The functional monomer is glycidyl
It is preferably methacrylate, allyl glycidyl ether or glycidyl functional aromatic monomer.

Further, the polymer film or the polymer fiber may be formed by plasma, ozone, corona discharge, ultraviolet irradiation, or by means of forming a peroxide or hydroperoxide on the surface of the polymer film or the polymer fiber. It is preferable to pre-activate before surface graft copolymerization.

The polymer film or the polymer fiber is immersed in an aqueous solution, an organic solution or an emulsion containing a functional monomer, and the resulting coating is treated with heat or near-ultraviolet light to form the surface. It is preferable to cause graft copolymerization.

Further, the polymer fiber is preferably an aramid fiber, an aromatic nylon fiber, an ultra-high module polyethylene fiber, a carbon fiber or a graphite fiber.

[0052]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to non-adhesive bonding between two polymer surfaces upon direct contact in the presence of water (or solvent) and subsequent drying. This property is
It can be applied to the surface of most polymers, such as polyolefins, polyesters, hydrocarbon polymers, fluoropolymers and electroactive (conductive) or conjugated polymers. The non-adhesive properties of the polymer surface may include functional monomers such as, but not limited to, acrylic acid (AAc), acrylamide (AA
m), Na salt of styrene sulfonic acid (NaSS), N,
N-dimethyl acrylamide (DMAA), N, N-
Dimethylpropyl acrylamide (DMAPAA),
It is introduced by surface graft copolymerization of a polymer substrate using an epoxy group-containing monomer, a hydroxyl group or amine-containing monomer, an electrolyte monomer, and a polyamphoteric monomer. Also, high module polymer fiber (or polymer film)
Adhesive-free adhesion is also achieved by covalent bonding of the surface grafted epoxide-containing polymer to the epoxy matrix in a fiber reinforced (or laminated) composite.

Without wishing to be bound by any theory, the present invention does not rely on an adhesive by introducing a functional polymer onto the surface of a polymer film or substrate by graft copolymerization. It is believed to be due to the fact that adhesive properties are imparted between the two polymer surfaces. Thus, a thin film or substrate of a surface-modified polymer can be used to form other similar modified thin films or substrates when in intimate contact with others in the presence of a small amount of solvent for the graft chains. The material (not necessarily the same substance) can be bonded without using an adhesive.
The adhesion, measured by lap shear strength, depends on the nature of the interaction between the graft chains in the lap joint. The interface interaction is based on dielectric force, dispersion force (van d
er Waals), ionic forces, covalent forces, electrostatic forces and H-bond forces. In all cases, chain diffusion and entanglement in the lap joint play an important role in the resulting adhesion. The type of interface interaction is determined by the type of functional group on the surface graft polymer. The extent of entanglement, on the other hand, depends on the surface grafting efficiency.

It is well known in the literature that many vinyl monomers are susceptible to near ultraviolet or thermally induced radical polymerization. The monomers used in the present invention are selected from the group of vinyl monomers. The graft copolymerization reaction is initiated by radicals generated on the surface of the substrate. Thus, prior to graft copolymerization, the substrate film is pretreated by plasma, ozone, corona discharge, or other chemical or physical means to coat the surface with a peroxide or hydroperoxide species. The peroxide species is then decomposed by thermal or near-ultraviolet radiation, initiating a surface graft copolymerization reaction in the presence of the monomer or monomer mixture.

The selection of the type of pretreatment of the surface for the base film before the surface graft copolymerization is particularly important. The choice of surface pretreatment for chemically inert surfaces, such as the surface of most fluoropolymer films, is limited to plasma treatment and corona discharge. The choice of surface pretreatment method for polyolefins, polyesters, polyimides, polycarbonates and hydrocarbon films is less critical. For conjugated electroactive polymer films, surface graft copolymerization proceeds without any surface pretreatment.

The choice of monomer concentration used in the graft copolymerization is such that the preferred concentration for most monomers is 10% by weight.
That is all, but not particularly important. At low monomer concentrations,
It will take longer polymerization time to reach comparable surface grafts. However, the degree of surface graft copolymerization strongly affects the observed lap shear strength, since the lap shear strength depends on the degree of chain entanglement and the degree of interaction of the functional groups. It may be appropriate to emphasize that high graft concentrations should be present on one side of the film to promote chain diffusion and entanglement, even in the presence of strong electrostatic interactions. The most favorable adhesion results are observed when (i) both chain entanglement and electrostatic interaction are present, and (ii) covalent bonds or crosslinks occur between the two wrap surfaces.

If there is sufficient chain diffusion, entanglement, electrostatic and / or covalent interaction in the lap joint, the non-adhesive bond may be used for two similar substrate films, or two dissimilar ones. Between the base films. It should be noted, however, that polymer films of different chemical structures exhibit different sensitivities to graft copolymerization using selected monomers under the same experimental conditions. For substantial adhesion strength, the number of repeat units of the graft polymer per repeat unit of the substrate chain should exceed 1.0 at the top 100 points on the substrate surface.

For polymer surfaces grafted with anionic and cationic polymer chains, substantial and substantial adhesive interaction is also due to sufficient chain diffusion, entanglement and electrostatic interaction. Provided that they are present at the junction
Observed between lap joints in aqueous media.

[0059]

The following examples are provided to illustrate the invention and methods of practicing it. However, the specific detailed description given in each example has been selected for illustrative purposes and should not be construed as limiting the invention. In the examples, all parts and percentages are by weight unless otherwise indicated. In Examples 2 to 6, a product having a fixed contact area of 0.5 cm × 0.5 cm and a film size of 0.5 cm × 2 cm was used. Unless otherwise stated, all modified films were obtained from graft copolymerization with a 10% monomer solution. Example 1 describes in detail an experimental method of surface graft copolymerization using a functional monomer.

Example 1 In a preferred experimental scale method, a polymer film or a clean conjugated polymer film (size: 1.5 cm × 3.5 cm) pretreated with Ar plasma, pretreated with ozone, or pretreated with corona discharge was prepared. Immersed in 20 ml of the monomer solution in a Pyrex tester. Monomer concentration of 1
Changed between ~ 50%. Suitable concentrations were greater than 10%. Each reaction mixture (coating) was thoroughly degassed and sealed in a nitrogen atmosphere. Then, near-ultraviolet irradiation treatment was performed for about 0.5 to 2 hours using a 150 W xenon arc source. Alternatively, the reaction mixture was kept in a constant water bath for 0.5-2 hours. Water bath temperature 65
Changed at ９０90 ° C. In all cases, the reaction temperature and reaction time depended on the nature of the substrate, the reactivity of the monomers and the required graft concentration. After each grafting experiment, the polymer film was removed from the viscous homopolymer, washed with a large amount of polymerization solvent, and then placed in a continuously stirred water tank for 24-72.
Washing and immersion were repeated for a period of time to remove the residual homopolymer. The surface-modified film was then dried under reduced pressure using a pump.

Example 2 A water-soluble monomer used for graft copolymerization, acrylic acid (A
Ac) was obtained from Wako Pure Chemical Industries and a poly (tetrafluoroethylene) (PTFE) film having a thickness of about 0.01 cm and a density of 2.18 g / cm ³ was obtained from Goodfellow Inc. of UK.
Purchased from. The surface of the film was washed by Soxhlet extraction in methanol for 6 hours before use. Solvents and other reagents were for analysis and were used without further purification.

A PTFE film of about 1.5 cm × 3.5 cm was pretreated with Ar plasma before graft copolymerization. Bell jar type glow discharge cell manufactured by Shimadzu Corporation
Plasma treatment was performed using model LVCD12. The working frequency was 5 kHz with a plasma power of 28 W (280 V, 100 mA). The film was fixed on a stainless steel sample holder rotating between two lithographic electrodes. The distance between the electrodes was 8.0 cm. The pressure of the bell jar was maintained at 0.04 Torr with Ar when the polymer film was subjected to glow discharge treatment for 5 to 40 s.
The Ar plasma pre-treated film was exposed to the atmosphere before graft copolymerization.

Each PTFE film was immersed in 20 ml of the aqueous monomer solution in a Pyrex test tube. The concentration of the AAc solution was varied from 1 to 10% by weight. Each reaction mixture was thoroughly degassed and sealed under a nitrogen atmosphere. Then 1
Rotary Photochemical Reactor (Riko Rotary Model RH) equipped with a 000 W high-pressure mercury (Hg) lamp
400-10W) for about 30 minutes, near-ultraviolet (wavelength> 29)
0 nm). After each graft experiment, the PTFE film was removed from the viscous homopolymer solution and washed with a stream of double distilled water. Thereafter, the film was immersed in a water bath at 60 ° C. for 24 hours with continuous stirring, and rinsed with a large amount of distilled water to remove the residual homopolymer.

Two similar acrylic acid graft copolymerized polytetrafluoroethylene (PTFE) films were brought into intimate contact with each other under load in the presence of water. The development of the bond strength depends on the bond (drying) time of the lap boundary. The lap shear strength increased monotonically with the bonding time. When the bonding time exceeds 300 minutes, the adhesive strength between the films becomes strong. Therefore, the lap shear strength of all film pairs graft-copolymerized with a 1 to 10% acrylic acid solution is 0.1 mm thick polytetrafluoroethylene. Exceeds the tensile yield strength of fluoroethylene film.

Example 3 A water-soluble monomer, N, N-dimethylacrylamide (DMAA), used for graft copolymerization was purchased from Wako Pure Chemical Industries. Poly (tetrafluoroethylene) (PTF
E) A film was purchased and treated as in Example 2.

Degassing treatment was performed using 0.05 mM riboflavin 5
A similar method for plasma pretreatment of the PTFE film, graft copolymerization with DMAA, was employed, except that it was replaced by using ml. In this case, the dissolved oxygen could prevent radical polymerization, but was consumed by the photochemical reaction with riboflavin. X-ray photoelectron spectroscopy (XP) by both degassing and riboflavin addition
As shown in the result of S), a DMAA graft copolymerized PTFE having similar properties was obtained.

The AAc graft copolymerized polytetrafluoroethylene film and the DMAA graft copolymerized polytetrafluoroethylene film prepared in Example 2 were brought into intimate contact with each other under a load in the presence of water. 0.
Strong adhesion with lap shear strength reaching the yield strength of a 1 mm thick substrate was again observed. By extending the plasma pretreatment time to increase the degree of surface graft copolymerization,
Increasing the degree of electrostatic (ionic interaction) interaction results in a uniform increase in lap shear strength over the entire bonding time.

Example 4 In another preferred non-adhesive bonding experiment, two similar acrylic acid graft copolymerized low density polyethylene (LDPE) films (Goodfellow In
c. , Cambridge, UK) or two similar N, N-dimethylacrylamide graft copolymerized LDPE films, or an acrylic acid graft copolymerized (LDPE) film and an N, N-dimethylacrylamide graft copolymerized LDPE film. And intimate contact under load. For a wrap "heterojunction" containing both the grafted acrylic acid polymer and the N, N-dimethylacrylamide polymer, even if the wrap junction is still "wet", there is an electrostatic (ionic) interaction. Interface adhesion develops rapidly. In all cases, the lap shear bond strength was 0.125 mm thick LDP
The tensile yield strength of the E film was easily exceeded.

Example 5 In another preferred non-adhesive bonding experiment, two similar acrylic acid graft copolymerized LDPE films were tightly bonded under load in the presence of a small amount of a 10% ZnCl ₂ aqueous solution. I let it. In the absence of salt, the addition of ZnCl ₂ compared to the adhesive strength of the lap joint increases the interfacial adhesive strength because Zn ions promote the formation of intermolecular ionic bonds in the graft chains from the two surfaces. The result was a rapid expansion. Cd, other divalent and multivalent ionic salts gave similar results. Bonds formed using monovalent salts exhibited a corresponding low binding energy.

Example 6 In this preferred adhesion experiment without an adhesive, adhesion between two chemically distinct polymer substrates is achieved. The lap shear adhesive strength exceeding the tensile yield strength of both base films is between the acrylic acid graft copolymerized LDPE film and the acrylic acid graft copolymerized PTFE film, the acrylic acid graft copolymerized LDPE film and the N, N-dimethylacrylamide graft. Between a copolymerized PTFE film, and between an N, N-dimethylacrylamide graft copolymerized LDPE film and an acrylic acid grafted PT
It was easily exhibited between the FE film. For the latter two interfaces, electrostatic (ionic) interactions also worked.

Example 7 In this preferred adhesion experiment without an adhesive, a 3-dimethyl (methacryloylethyl) ammonium propane sulfonate (DMAPS) polymer (DJL) was used.
iaw and W.C. F. Lee, J.M. Appl. Po
lymer Sci. , Vol. 30, pp. 4697
No.-4706 (1985)) and two polycarbonate films with a surface grafted amphoteric polymer (Goodfellow Inc., C
abridge (obtained from UK) was brought into intimate contact under load in the presence of water. Interface contact was substantially enhanced by the simultaneous presence of cationic and anionic functional groups on the same grafted chain on each surface. The lap shear strength (beyond 100 N / cm ² ) between the two DMAPS-grafted copolycarbonate films is the tensile yield strength of the substrate film, or between the two cationic polymer graft surfaces, or the two anionic polymer grafts. Between surfaces (about 50 N / cm ² )
Remarkably larger, and further, an anionic polymer (acrylic acid polymer) graft surface (an acrylic acid monomer manufactured by Wako Pure Chemical Industries, Ltd. on the surface graft copolymerized) and a cationic polymer (N, N-dimethylacrylamide) graft surface (Aldrich Chemical Co., Mil
Waukee, US, surface graft copolymerized with the corresponding monomer).

Example 8 In another preferred non-adhesive bonding experiment, two electroactive polyaniline films (in a basic form similar to emerald) with a surface-grafted DMAPS polymer (M. Angelopoulos, G.E.A.
star, S.M. P. Ermer, A .; Ray, E .; M.
Scherr, A .; G. FIG. MacDiarmid, M .; A
khtar, Z .; Kiss and A. J. Epst
ein, Mol. Cryst. Liq. Cryst. ,
Vol. 160, 151 (1988)), or a DMAPS graft copolymerized polyaniline film and an acrylic acid graft copolymerized polytetrafluoroethylene film were brought into intimate contact under a load in the presence of water. . The polyaniline film did not undergo any surface pretreatment before graft copolymerization. Strong lap shear adhesion was again observed for two types of interfaces containing electroactive conjugated polymers. Lap shear bond strength for the bonding of the two equivalent is, 330N / cm ² and 100 N / cm ²
Was over.

Example 9 Further, in another suitable adhesive experiment without an adhesive, a surface-grafted glycidyl methacrylate polymer (Aldrich Chemical Co., Mil)
A polytetrafluoroethylene film comprising the corresponding monomer obtained from Waukee, US and surface graft copolymerized) was used to prepare a surface grafted N- (hydroxymethyl) acrylamide polymer (Aldrich Chem).
icalCo. The corresponding monomer was obtained from Milwaukee, US and surface graft copolymerized) and wrapped with other polytetrafluoroethylene films. In the interface epoxy curing reaction, the lap shear adhesion easily exceeded 120 N / cm ² .

Example 10 In another suitable adhesion experiment without an adhesive, a surface-grafted glycidyl methacrylate (GM
A) Ultrahigh Modular Polyethylene Fiber with Polymer (Goodfellow Inc., Cambridge)
e, available from UK) showed that the micro-peel strength increased by a minimum of three-fold relative to clean (non-grafted) fibers in the epoxy matrix of the fiber reinforced composite (Hitachi Chemical). Elevated interface adhesion is due to graft G
Due to the covalent attachment of the epoxy groups of the MA polymer to the amine in the epoxy resin matrix hardener.

For those skilled in the art to which the present invention pertains, many variations on construction, wide variations on the embodiments,
The application of the present invention is readily indicated by itself without departing from the spirit or scope of the invention. The disclosures and statements in this document
It is merely an example and is not intended to limit the present invention in any way.

Continued on the front page (72) Inventor Chin-Cheng Fan Taiwan, Taipei, National Taiwan Institute of Technology, Department of Chemical Engineering , National University of Singapore, Department of Chemical Engineering Country 119260, Kent Ridge, National University of Singapore, Department of Chemical Engineering

Claims (41)

[Claims] 1. a) modifying the surface of a first polymer substrate by surface graft copolymerization with a first functional monomer capable of undergoing radical-initiated polymerization; b) modifying the surface of a second polymer substrate Modified by surface graft copolymerization with a second functional monomer capable of undergoing radical-initiated polymerization; c) modifying the modified surface of the first polymer substrate in the presence of a liquid medium with the second polymer substrate And d. Maintaining said contact until said liquid medium is substantially dry. 2. The method according to claim 1, wherein the first polymer substrate is formed by subjecting the first polymer substrate to plasma, ozone, corona discharge, ultraviolet irradiation, or peroxide or hydroperoxide.
The method of claim 1 wherein the means for forming on the surface of the polymer substrate is preactivated before surface graft copolymerization in step a). 3. The second polymer substrate is formed by subjecting the second polymer substrate to plasma, ozone, corona discharge, ultraviolet irradiation, or peroxide or hydroperoxide.
A method according to claim 1, wherein the surface is preactivated prior to surface graft copolymerization in step b) by means of forming on the surface of the polymer substrate. 4. The first polymer substrate is immersed in an aqueous solution, an organic solution or an emulsion containing the first functional monomer, and the resulting coating is treated with heat or near-ultraviolet light to obtain the first polymer substrate. 2. The method of claim 1, wherein the method causes surface graft copolymerization. 5. The second polymer substrate is immersed in an aqueous solution, an organic solution or an emulsion containing the second functional monomer, and the obtained coating is treated with heat or near-ultraviolet light to obtain a coating. 2. The method of claim 1, wherein the method causes surface graft copolymerization. 6. The method according to claim 1, wherein said first polymer substrate is in the form of a film. 7. The method of claim 6, wherein said second polymer substrate is in the form of a film. 8. The method according to claim 6, wherein said second polymer substrate is fibrous. 9. The method of claim 1, wherein the first polymer substrate and the second polymer substrate are each independently selected from a polyolefin or a hydrocarbon polymer. 10. The method of claim 9, wherein said polyolefin is high density polyethylene, low density polyethylene or polypropylene and said hydrocarbon polymer is polystyrene or polycarbonate. 11. The method according to claim 1, wherein the first polymer substrate and the second polymer substrate are each independently a fluoropolymer or a halogen-containing polymer. 12. The fluoropolymer is polytetrafluoroethylene; a copolymer of tetrafluoroethylene and hexafluoropropylene; a copolymer of tetrafluoroethylene and perfluoro (propyl vinyl ether); Fluoro 2,2-
A copolymer with dimethyl-1,3-dioxide; poly (vinyl fluoride); poly (vinylidene fluoride); or a vinyl fluoride / vinylidene fluoride copolymer; and the halogen-containing polymer is tetrafluoroethylene. The method according to claim 11, which is a copolymer with vinyl chloride; polychlorotrifluoroethylene; vinylidene fluoride / hexafluoroethylene copolymer; poly (vinyl chloride) or poly (vinylidene chloride). 13. The method of claim 1, wherein said first polymer substrate and said second polymer substrate are each independently a polyester. 14. The polyester according to claim 1, wherein the polyester is poly (ethylene).
14. The method according to claim 13, which is terephthalate). 15. The method of claim 1, wherein said first polymer substrate and said second polymer substrate are each independently a thermosetting material. 16. The method according to claim 15, wherein said thermosetting material is an epoxy polymer, a polyimide, a polyurethane or a phenolic polymer. 17. The method according to claim 2, wherein the first polymer substrate and the second polymer substrate are each independently an electroactive conjugated polymer, and the electroactive conjugated polymer is used before surface graft copolymerization.
2. The method of claim 1, wherein the method does not undergo preactivation as defined in paragraph (1). 18. The method according to claim 17, wherein the electroactive conjugated polymer is a polymer of aniline, pyrrole, thiophene or acetylene. 19. The method according to claim 1, wherein the first functional monomer and the second functional monomer are each independently a hydrophilic vinyl monomer. 20. The method according to claim 19, wherein the hydrophilic vinyl monomer is an acrylic acid-based monomer, acrylamide, a sulfonic acid-containing monomer or an acrylate. 21. The first functional monomer and the second functional monomer are each independently selected from the group consisting of an electrolyte monomer and an amphoteric monomer. 2. The method according to 1. 22. The first functional monomer and the second functional monomer are each independently dimethyl sulfate.
Quaternized dimethylaminoethyl methacrylate (D
MAEM. C ₂ H ₆ SO ₄ ), 2-acrylamino-2
22. The method according to claim 21, which is -methyl-propanesulfonate, 3-dimethyl (methacryloylethyl) ammoniumpropanesulfonate (DMAPS) or 3-dimethyl (acryloyloxyethyl) ammoniumpropanesulfonate (DAAPS). 23. The method according to claim 1, wherein the first functional monomer is an epoxy-containing monomer, and the second functional monomer is an epoxy-curable monomer. 24. The epoxy-containing monomer is glycidyl methacrylate, allyl glycidyl ether or glycidyl functional aromatic monomer, and the epoxy-curable monomer is N- (hydroxymethyl) acrylamide or N- 24. The method according to claim 23, which is butoxymethyl acrylamide. 25. The method according to claim 1, wherein the first functional monomer and the second functional monomer are hydrophilic monomers. 26. The method of claim 25, wherein each of said first polymer substrate and said second polymer substrate is modified with a graft hydrophilic polymer. 27. The method of claim 25, wherein each of said first polymer substrate and said second polymer substrate is modified with a graft anionic polymer. 28. The method of claim 25, wherein each of said first polymer substrate and said second polymer substrate is modified with a grafted cationic polymer. 29. The method of claim 25, wherein said first polymer substrate is modified with a grafted cationic polymer and said second polymer substrate is further modified with a grafted anionic polymer. 30. Each of the first and second polymer substrates is modified with a graft polyelectrolyte.
5. The method according to 5. 31. The first polymer substrate and each of the second polymer substrates are modified with a zwitterionic polymer.
The method described in. 32. Each of the first polymer substrate and the second polymer substrate is modified with a graft amphoteric polymer.
5. The method according to 5. 33. The first polymer substrate is modified with a graft amphoteric polymer, while the second polymer substrate is modified with either a graft cationic polymer or a graft anionic polymer. The method described in. 34. The method according to claim 25, wherein said liquid medium is water. 35. The method according to claim 23, wherein the liquid medium is water or an organic solvent for an epoxy resin. 36. A polymer film or fiber,
Before impregnating the polymer film or polymer fiber with the liquid resin, the liquid resin has a first functional group capable of undergoing a radical initiation polymerization reaction and a second functional group capable of reacting with a curing agent contained in the liquid resin. Enhance the coupling between resin film or polymer fiber and polymer matrix when producing film or fiber reinforced resin composite characterized by modification by surface graft copolymerization with functional monomer Method. 37. The liquid resin is an epoxy resin,
37. The method of claim 36, wherein the second functional group is an epoxy group and the curing agent is a secondary, tertiary, or quaternary amine. 38. The method according to claim 36, wherein the functional monomer is glycidyl methacrylate, allyl glycidyl ether or glycidyl functional aromatic monomer. 39. The polymer film or the polymer fiber may be formed by plasma, ozone, corona discharge, ultraviolet irradiation, or by means of forming a peroxide species or a hydroperoxide species on the surface of the polymer film or the polymer fiber. 37. The method of claim 36, wherein the method is preactivated before surface graft copolymerization. 40. The polymer film or the polymer fiber is immersed in an aqueous solution, an organic solution or an emulsion containing a functional monomer, and the resulting coating is treated with heat or near-ultraviolet radiation to form the surface. 37. The method according to claim 36, which causes graft copolymerization. 41. The polymer fiber comprises an aramid fiber, an aromatic nylon fiber, an ultra-high module polyethylene fiber,
37. The method according to claim 36, which is a carbon fiber or a graphite fiber.