JPS63135207A - Joining method - Google Patents

Abstract

PURPOSE:To contrive to improve the workability of joining by a method wherein anaerobic and activation energy ray-curing type liquid primer is laminated onto the joint area of a base material and activation energy rays irradiates over the primer layer in the presence of oxygen and, after that, curing type liquid resin is laminated onto the primer layer and finally the curing liquid resin layer and the primer layer are cured together with each other. CONSTITUTION:Firstly, anaerobic and activation energy ray-curing type liquid primer is laminated onto a base material by the predetermined thickness. At this time, when the primer layer contains solvent, the solvent is necessary to be dispelled by drying or the like, but not necessary to be dispelled completely. Next, activation energy rays irradiates over the primer layer in the atmosphere containing oxygen such as in the air or the like so as to cure the primer layer under the condition that the surface of the primer layer is still in un-cured state. After that, curing type liquid resin is laminated onto the primer layer by the predetermined thickness. Finally, both the un-cured part of the primer layer and the curing type liquid resin laminated thereonto are preferably simultaneously cured by radiating activation energy rays, heating or the like. At this time, in case that the curing type liquid resin is one to be cured by the activation energy rays same as the liquid primer, the preferable simultaneous and efficient curing of both the un-cured part of the primer layer and the curing type liquid resin is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a bonding method for imparting strong adhesiveness between a substrate and a cured product of a curable liquid resin.

(Prior Art) In recent years, with the development of optronics and mechatronics, the need for optical precision molded products having complex and fine shapes on a base material has increased. A typical example of this is an optical disk, which is seen as a promising optical storage medium. The source disk requires a transparent substrate having unevenness on its surface with a height of about 1 .mu.m and a width of about 5 .mu.m in order to guide the radar source of the laser pick-up. Currently, the mainstream manufacturing method for this board is to injection mold a transparent resin such as polycarbonate or polymethyl methacrylate in a mold, but since high viscosity molten resin is injected into a mold, There is a drawback that birefringence occurs due to the orientation due to the flow of the resin within the mold, which tends to cause trouble in reading the signal by the laser source. In addition, the viscosity of the molten resin is high, and it is difficult to fill the molten resin into minute shapes without voids, which tends to cause shape defects.Moreover, because a large molding machine that uses high temperatures is used, the molded product - per piece Another disadvantage is that the energy cost is high.

In order to improve these defects, cast molding is used to fill the space between a shaped metal sheet and a transparent glass substrate with an ultraviolet-curable liquid resin, and then harden it to transfer the surface shape of the world onto the substrate. A method has been devised.

(Problems to be solved by the invention) The liquid resin used in this molding method must be able to quickly fill the gap between the base material and the mold, and must have a low viscosity by using a resin with a small molecular weight. be.

However, low-viscosity liquid resins with small molecular weights shrink significantly during curing, and stress concentrates on the bonding surface between the base material and the cured liquid resin. There is a problem that peeling is likely to occur.

Under these circumstances, a film of a silicone-based liquid release agent such as dimethylpolysiloxane or a fluorine compound-based liquid release agent such as polytetrafluoroethylene is formed between the film and the cured liquid resin, and the film and the liquid resin are cured. There is a method to improve the mold releasability between the materials and prevent them from peeling off during mold release even if the adhesiveness between the base material and the cured liquid resin is weak, but this method prevents the oil film caused by the application of the dispersing agent from forming. It has the disadvantage that it adheres to the surface of objects and deteriorates the optical properties and dimensional accuracy of molded objects.

(Means for Solving the Problems) As a result of intensive study in view of the above situation, the present inventors laminated an anaerobic active energy ray-curable liquid glymer on the bonding surface of the base material, and removed oxygen. When cast molding is performed after irradiation with active energy rays in the presence of active energy rays, the cured product of the cured liquid-reduced resin and the base material are strongly bonded via the primer layer, and the base material can be formed without using a mold release agent. We discovered that it is possible to obtain a cast molded product that does not cause peeling between the material and the cured liquid resin, and that this joining method can be applied not only to implantation molding but also to general joining of base materials and hardened liquid resins. The invention was completed.

That is, in the present invention, an anaerobic active energy ray-curable liquid primer is laminated on the joint surface of the base material.

After irradiating with active energy rays in the presence of an acid, a curing hot liquid resin is laminated on the primer layer, and then the curing hot liquid resin layer and the primer layer are cured. The present invention provides a method for joining a material and a cured product of a curable liquid resin.

There are no particular limitations on the base material used in the present invention.

For example, metals, ceramics, glass, plastics,
Examples include wood and paper. Base materials with excellent external transparency, such as glass, polymethyl methacrylate, polycarbnate, epoxy resin, polyester, polyvinyl chloride, and acrylic resin, are transparent to infrared, visible, and ultraviolet electromagnetic waves. A curable liquid resin that cures with active energy rays in these wavelength ranges can be used and is efficient, which is preferable.

Note that active energy rays here refer to electromagnetic waves and particle beams that can cure a curable liquid primer.
Examples include visible light, ultraviolet light, infrared rays (heat rays), electron beams, and ion beams.

The anaerobic active energy ray-curable liquid primer used in the present invention is a primer that is activated by active energy rays or active energy rays such as a radical/L/initiator or a photoinitiator as at least one of its components. It has at least one group in its molecule that causes a polymerization reaction or crosslinking reaction depending on the chemical species, and the polymerization reaction and crosslinking reaction are inhibited by the presence of oxygen, such as a vinyl group, an acrylic group, or a methacrylic group. III#, containing an i-active energy ray-curable liquid compound, and further containing a volatile organic solvent, a photopolymerization initiator, a photosensitizer, other additives, etc. that may be added as necessary. To tell.

Examples of the anaerobic active energy ray-curable hot liquid compound used here include polyester (meth)acrylate,
Epoxy (meth)acrylate.

Examples include urethane (meth)acrylate, poly-JL/(meth)acrylate, (meth)acrylate monomer, and vinyl monomer. Among these, those having an acrylic group are preferred because they have high reactivity to active energy rays, shorten the curing time, and have good adhesion to substrates made of acrylic resins and the like.

Specific examples of these are shown below: polyester acrylate, eboxy acrylate, urethane acrylate, polyol acrylate, acrylic monomer, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, nato-2hydrofurfuryl acrylate. , isozolonyl acrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, trimethylolpronoglycol diacrylate, hydroxypiparic acid Ester neopentyl glycol diacrylate,
Pentaerythritol triacrylate, dipentaerythritol hexaacrylate, tetramethylolmethane triacrylate: Vinyl monomers include N-vinyl bialidone, styrene, etc., and each is used alone or in a mixture of two or more.

The thickness of the liquid primer layer laminated on the substrate in the bonding method of the present invention is not necessarily limited, but the thickness of the primer layer after curing is usually 100 μm or less, preferably 0 μm or less.
．． It is in the range of 5 to 50 μm, particularly preferably 1 to 20 μm. Since the liquid brimer is laminated to such a thickness, the viscosity of the liquid brimer is usually 0.1 to 1,000 centipoise.
Among these, a range of 1 to 100 centipoise is preferable, and when using a highly viscous oligomeric anaerobic active energy ray-curable liquid compound, it is preferable to dilute it with a volatile organic solvent such as alcohol or chthonic solvent. is normal.

The curing temperature liquid resin used in the present invention is not particularly limited, and can be cured by heat, moisture, oxygen, or active energy rays. M
Any general resin that changes from a movable liquid state to a solid state can be used, but the above-mentioned liquid state! It is preferable that the primer is cured by the same active energy rays as the primer because it can be cured simultaneously with the uncured portion of the single layer of the primer by irradiation with the active energy rays. If the reaction is the same, for example, if both are radical reactions, it is particularly preferable in that a covalent bond is generated between the primer layer and the liquid primer layer upon curing, and a very strong adhesive force can be obtained.

Examples of the curable liquid resin include polyester (meth)acrylate, polyurethane (meth)acrylate, and epoxy (meth)acrylate.

Contains one or more compounds selected from polyol (meth)acrylate, (meth)acrylate monomer, vinyl monomer, etc., and further contains a thermal polymerization initiator, photopolymerization initiator, photosensitizer, and other additives as necessary. , a solvent, and the like.

Among them, solvent-free acrylic active energy ray-curable liquid resins do not require solvent removal and have a fast curing speed.
Moreover, since it can be cured at a low temperature, there is no problem such as deformation of the base material, which is preferable. , 25 to 75% by weight of an acrylic acid ester with a molecular weight of 130PJ1,000 having two acryloyl groups in the molecule, and 5 to 50% of an acrylic monomer having three or more acryloyl groups in the molecule.
The bath-free acrylic ester resin, which consists of
As a result, a bonded product with excellent adhesiveness, strength, and rigidity can be obtained, which is preferable.

Next, the procedure for carrying out the joining method of the present invention will be explained.

For example, first, the above-mentioned anaerobic active energy ray-cured liquid Zolaimer is laminated to a predetermined thickness on a base material. The lamination method is not particularly limited, but dipping methods, spray methods, spin coater methods, etc. are preferred. At this time, if the primer layer contains a solvent, it is necessary to scatter the cleaning bath agent for drying, etc., but it is not necessary to completely scatter it.

Next, the primer layer is irradiated with active energy rays in an atmosphere containing oxygen such as air to cure the primer layer while the surface remains uncured, and then a curable liquid resin is laminated thereon to a predetermined thickness. This lamination method is also not particularly limited, and includes, for example, a barcode method and a roll coating method.

Suff'l/- method, dipping method, spin code method,
There are silk screen methods, curtain coat methods, etc.

However, the surface of this laminated hardening liquid resin has a mirror surface,
When giving a matte surface or other uneven shapes, for example when pouring molding the original disk, it is necessary to laminate a primer layer and a matte surface to give the shape. There is a method of filling a curable liquid resin between the base material and the base material by injecting, press-fitting, or the like.

In addition, according to the bonding method of the present invention, since the base material and the cured product of the curable liquid resin are strongly bonded via the primer layer,
Even with molding methods that tend to cause problems such as peeling during mold release, such as potting molding of the original disk, peeling rarely occurs, but a surface treatment agent containing fluoroalkylsilane is applied to the surface. By using a surface-treated mold that is cured after lamination or coating, a long-lasting release effect can be obtained without deteriorating the optical properties or dimensional accuracy of the molded product.
This is preferred because workability is significantly improved.

As the surface treatment agent used here, for example, fluoroalkylsilane is used in a concentration range of 0.01 to 5% by weight, and if necessary, a solvent such as water or alcohol is used together with other silane coupling agents, alkoxysilane, etc. Examples of the fluoroalkylsilane include CF3CH2CH25t (OCH,), CF, (O
F'2)5CH2CH2S 1(OCI(3),,CF
s(CF2), CH2CH281(OCR,)3, CF
3(CF2)7CH2CH2Sl(OCH5)3, CF
, (CF2), CH2CH2S i (CH3XOCH
, ), etc.

In addition, when bonding base materials together using the bonding method of the present invention, one or both of the two base materials having a primer layer with an uncured surface obtained in the same manner as above! A method of laminating and overlapping a curable liquid resin on one layer of limer, or 2.
A method may be used in which the primer layer sides of the two base materials are placed opposite each other and a curable liquid resin is injected or press-fitted therebetween.

Finally, both the uncured portion of the primer layer and the cured hot liquid resin layer thereon are cured, preferably substantially simultaneously, by irradiation with active energy rays, heating, or the like.

At this time, it is preferable that the curable liquid resin is one that is cured by active energy E rays similar to the liquid brimer, since the uncured portion of the brimer 1 can be efficiently cured at the same time.

(Effects of the Invention) When the bonding method of the present invention is used, the base material and the cured product of the curable liquid resin are bonded with strong adhesive force via the primer layer. The reason for this is that first, the anaerobic active energy ray-curable liquid primer layer laminated on the base material is irradiated with active energy rays in the presence of oxygen, so the primer layer is only half formed on the bonding surface with the base material. Cured to completely cured, preferably completely cured, but due to the curing inhibiting effect of oxygen, curing is gradually inhibited from the bonding surface side with the base material toward the surface side,
The surface is in an uncured state with tackiness remaining, and as a result, the concentration of stress due to hardening and shrinkage of the brimer on the joint surface side is alleviated by the presence of the uncured brimer, and there is no or little residual stress. Because the cured primer layer is formed on the surface to be bonded to the base material, and because the cured liquid resin is then laminated on the uncured primer layer, the liquids are not laminated, and as a result, both liquids are compatible with each other. Although the layers do not necessarily have to be cured at the same time, it is possible that curing the layers preferably at approximately the same time would result in the two layers being integrated without a clear interface.

(Example) The present invention will be specifically described below with reference to Examples and Comparative Examples. In addition, all parts and parts in the examples are based on weight.

Example 1 An L-shaped metal ac IJ with a width of 10 mm, a height of 10 mm, a thickness of 1 m+, and a bottom surface (joint surface) of 10 m x 10+ m) was coated with dimethylol on the bottom surface of two resin plates. An ultraviolet curable liquid Zolaimer consisting of 15 parts of propane triacrylate, 15 parts of ingolonyl acrylate, 1 part of l-hydroxycyclohexylphenylketoph, 50 parts of methanol and 20 parts of isozorobyl alcohol was heated to a thickness of 3 μm after curing. After coating by spraying so as to give the following properties, the solvent was removed by heating at 50° C. for 5 minutes. Next, this primer layer was irradiated with ultraviolet rays at an intensity of 200 mJ/cm'' for 3 seconds using a high-pressure mercury lamp in the air to form two L-shaped metal sheets having a hardened primer layer on the bottom surface while one surface was uncured. An acrylic resin plate was obtained.

Next, between the primer layer on the bottom of these two L-shaped methacrylic plates, (wherein R4 and R2 represent an alkyl group, R1
and R2 have a total of 9 carbon atoms. 35 parts of acrylic monomer represented by ), 50 parts of acrylic monomer represented by
parts, 15 parts of trimethylolgulon triacrylate and 0 parts of 1-hydroxycyclohexylphenyl ketone.
．． A UV-curable liquid resin consisting of 5 parts was prepared so that the thickness after curing would be 200 μm, and UV rays were irradiated for 12 seconds at an intensity of 200 mJ/crn using a high-pressure mercury lamp to remove any remaining parts of the primer layer. It was cured simultaneously with the cured portion to obtain a sample in which two L-shaped methacrylic plates were joined.

Next, using this sample, a tensile test was performed in the direction perpendicular to the joint surface at a tensile speed of 1 m/min, and the load at the time of peeling was determined, and the average was 22.1 kl? , and the bonding force was extremely large.

Comparative Example 1 A sample in which two L-shaped methacrylic plates were bonded was obtained in the same manner as in Example 1, except that the use of the ultraviolet curable liquid primer was omitted. Next, when a tensile test was conducted in the same manner, the average load at the time of peeling was 4.8 kl? However, the bonding force was small.

Comparative Example 2 An L-shaped methacrylic plate was prepared in the same manner as in Example 1, except that instead of irradiating the liquid primer layer with ultraviolet rays in the air after coating and removing the solvent, the irradiation with ultraviolet rays was performed in a nitrogen atmosphere. A sample was obtained by bonding two sheets together, and then a tensile test was conducted in the same manner. When the load at the time of peeling was 4.1 kg on average, the bonding force was small.

Example 2 5 parts of polyester acrylate represented by: was placed on one side of a methacrylic resin plate having a width of 10011IIK, a length of Zoom, and a thickness of 1 m.

/' 15 parts of epoxy acrylate, 1 part of l-hydroxycyclohexylphenyl ketone.

After applying an ultraviolet curable liquid primer consisting of 50 parts of methanol and 20 parts of isopropyl alcohol to a thickness of 15 μm after curing by a spray method,
The solvent was removed by heating at 0° C. for 5 minutes. This primer layer is then exposed to 200% ultraviolet light using a high-pressure mercury lamp in the air.
Irradiation was performed for 3 seconds at an intensity of mJ/m2 to obtain a methacrylic resin plate having a cured primer layer on one side with the surface in an uncured state.

Next, on the surface, a width of 50 μm, a depth of 50 μm, and an interval of 75 μm
A nickel-plated AX brass mold with parallel grooves and a primer layer of the methacrylic resin plate were coated with ultraviolet light consisting of 30 parts of acrylic monomer, 70 parts of acrylic monomer, and 0.5 part of l-hydroxycyclohexyl phenyl ketone. The curable liquid resin was prepared so that the maximum thickness after curing was approximately 200 μm, and ultraviolet rays were irradiated from the methacrylic resin plate side for 12 seconds at an intensity of 200 mJ/cps using a high-pressure mercury lamp to form the primer layer. After curing at the same time as the uncured part of the methacrylic resin, the mold was released to obtain a laminated potted molded product having convex portions parallel to the surface. Peeling was observed at the interface between the resin plate and the cured UV-curable liquid resin, which was dangerous.

Example 3 The same brass metal backing as that used in Example 1 except that there was no nickel plating was used, and 2.2% was added to an oxidizing agent consisting of 18 parts of a 42% cupric chloride aqueous solution, 32 parts of concentrated nitric acid, and 200 parts of water.
After soaking for a minute, washing with water and drying to obtain a mold with an oxidized surface, this mold was diluted with CF, ( CF2), CH2CH281(OCH,),
After immersion for 30 minutes in a surface treatment agent containing
C. for 1 hour to obtain a mold surface-treated with fluoroalkylsilane.Convex portions parallel to the surface were obtained in the same manner as in Example 2 except that this surface-treated mold was used. Although a molded article with laminated properties was obtained, it was extremely easy to release from the mold, and no peeling was observed during mold release. Further, molding was performed 50 times using this mold, but there was no deterioration in mold releasability.

Comparative Example 3 A laminated pottery molded product having parallel convex portions on one surface was produced in the same manner as in Example 2 except that the use of an ultraviolet curing liquid primer was omitted. Peeling occurred at the interface between the curable liquid resin and the cured product.

Claims (1)

[Claims] After laminating an anaerobic active energy ray-curable liquid primer on the joint surface of the base material and performing active energy ray irradiation in the presence of oxygen, further laminating a curable liquid resin on the primer layer, A method for bonding a substrate and a cured product of a curable liquid resin, the method comprising: then curing the cured hot liquid resin layer and the uncured portion of the primer layer.