JPH08259849A - Primer composition and processing of slightly adherent plastic material - Google Patents

Abstract

PURPOSE: To obtain a primer composition to be used in bonding, coating, laminating and combining a slightly bondable plastic material and an inorganic material such as glass, ceramic, concrete, metal, etc., as an object. CONSTITUTION: This primer composition is obtained by blending (a) an acid modified styrene block resin having 3,000-100,000 Mw with (b) an epoxy-modified styrene block resin having 3,000-100,000 Mw and 0.5-7wt.% oxirane oxygen concentration in one molecule in the blending ratio of the carboxyl group of the component (a) and the epoxy group of the component (b) of 1:0.5 to 0.5:1 as the mol equivalent blending ratio and making the blend into a liquid state at a normal temperature with a good solvent for the components (a) and (b). The primer composition is previously applied to the surface of a slightly bondable plastic material or the surface of a metal in 1-50 micron film thickness as dried film thickness, dried, cured and aged and the plastic material or the metal is sent to a process such as bonding, coating, laminating or combining through the cured coating film of the primer.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a polycarbonate resin (hereinafter also referred to as PC), a polyester-polycarbonate resin (hereinafter also referred to as PEPC), a polypropylene resin (hereinafter also referred to as PP), a polyethylene resin (hereinafter referred to as PE), a polyethylene. Terephthalate resin (hereinafter PET)
When bonding, coating, laminating, and compounding difficult-to-bond plastic materials represented by polymethylmethacrylate (hereinafter referred to as P-MMA) and inorganic materials such as glass, ceramics, concrete, and metal. The present invention relates to a primer composition used and a pretreatment processing method thereof.

[0002]

2. Description of the Related Art As described in Japanese Patent Application Laid-Open No. 6-299089, conventionally, a lens part represented by PC, PEPC, glass, etc. of a vehicle part, such as an automobile headlamp, and PP, glass fiber are conventionally contained. Most of the adhesive seals with the housing part represented by PET and the like are performed by using a hot-melt type sealing material mainly composed of olefin, and its industrial benefit is widely known. From the perspectives of instant adhesiveness and pollution-free, it is building an increasingly important position. In addition, when applying acrylic paint, urethane paint, etc. to the surface of the material of vehicle parts such as PP bumpers for automobiles, a primer treatment of a chlorinated PP resin composition is carried out after ozone oxidation. Improving and developing primer compositions has become particularly important. In recent years, in the fields of vibration damping and sound insulation materials, composite steel plates, various shields, etc., especially in the fields of bonding steel plates to each other, bonding composites of steel plates and plastics, etc. From the viewpoint of cost reduction, the use of plastic as the outer plate is being studied. PC as a plastic material to achieve such purpose,
Difficult-to-adhesive plastic materials such as PEPC, PP, PE, and P-MMA have been frequently considered for use.

Along with this, the development of primer compositions, adhesives, and paints for various types of difficult-to-adhesive plastic materials has been actively conducted. Conventional techniques and processing methods for such a primer composition are as follows. For example, in the case of adhering PP to a metal, JP-A-58-58
According to Japanese Patent No. 117224, a primer composition comprising a silane compound having an unsaturated bond on a metal surface, a peroxide and a transition metal compound is proposed, but PP is oxidized by the peroxide when heated. It has the drawback of deterioration. Further, for example, Japanese Patent Application Laid-Open No. 62-273241 proposes a composition of an unsaturated carboxylic acid-modified PP resin and a benzoic acid metal salt as a polyolefin resin composition for improving adhesiveness. Is a thermoplastic molding resin composition that is solid at room temperature. Even if this composition is applied as a primer, the modified PP resin is crystalline,
At room temperature, it is almost insoluble in common solvents and therefore does not form a liquid primer composition. Further, for example, a primer solution of a metal compound of a higher fatty acid has been proposed as a primer for a PP material of an α-cyanoacrylate adhesive, but it is effective with an α-cyanoacrylate adhesive, but with other adhesives. The effect is extremely small.
Metal compounds of higher fatty acids are generally known as internal mold release agents for polymeric resins and appear to have limited compatibility with adhesives or coating compositions. In addition, it is generally recognized that the organic phosphite compound is effective in improving the adhesion durability of the above-mentioned poorly-adhesive plastic material, particularly PP. However, the primer treatment alone has the drawbacks that the water resistance of the product is lacking, and that in the case of general coated products, the coating composition undergoes severe hydrolysis and deteriorates.

[0004]

When PC, PEPC, P-MMA or the like used as a raw material is adhered, there is often a problem that the interfacial adhesion reliability is impaired. That is, when the above materials are adhered by, for example, a hot-melt adhesive, when the hot-melt sealing agent in a molten state at about 170 ° C. or higher is applied or bonded, a remarkable gas, which is considered to be water vapor, is generated from the surface of the material. Are observed, and as a result, micro voids (small adhesion defects) are left at the interface of the adhesive lens material. For this reason, the bonding reliability is significantly lost. When exposed to high temperatures, the microvoids generated during bonding will further enlarge the defective voids due to the steam gas generation stress from the material,
The appearance is also observed as an interfacial foaming state, and there is an important problem that results in a significant loss of the sealing property. Adhesion of materials such as PP and PE used as materials
When coating is carried out, a chlorinated PP resin-based primer composition is used in part. However, it still has a problem in that it lacks adhesion and that the coating composition and the adhesive composition are limited.

In the prior arts up to now, no good primer or a processing method therefor has been found for paints or hot-melt adhesives that can exhibit good heat-resistant adhesive properties. As described above, there is a strong demand for a primer composition having weather resistance, chemical resistance, heat resistance, and other adhesive reliability in a long-term environment that is compatible with general adhesives and paints. Therefore, the object of the present invention is to provide PC, PEPC,
When bonding and coating using difficult-to-adhere plastic materials such as PP, PE, PET, P-MMA, various long-term properties such as weather resistance, chemical resistance, and heat resistance that can be applied to general adhesives and paints. An object of the present invention is to provide a primer composition having adhesion reliability in an environment and a method of processing the same, and
For adhesion with C, PEPC, PET, P-MMA materials,
It is to solve the problem of interfacial foamability. Furthermore, metal and PC, PEPC, PP, PE, PET, P
-A primer having excellent adhesion to a metal and excellent affinity and durability with a melt-extruded resin when extrusion-molding such a hard-to-adhere plastic material even when compounded with a hard-to-adhesive plastic material such as MMA. Therefore, it is also an object of the present invention to provide a primer composition that can be preferably used in metal insert molding.

[0006]

Means for Solving the Problems As a result of intensive investigations by the present inventors, it has been found that the problem can be solved by forming a thermosetting coating composed of an acid-modified styrene block resin and an epoxy-modified styrene block resin on the surface of a poorly-adhesive plastic material. Heading, the present invention has been achieved.

That is, the present invention has the following weight-average molecular weights in the range of 3,000 to 100,000, preferably acid-modified hydrogenated styrene-butadiene resin, acid-modified hydrogenated styrene-butadiene-styrene resin, acid-modified styrene- One or two kinds of acid modification selected from ethylene-butylene-styrene resin, acid-modified hydrogenated styrene-isoprene resin, acid-modified hydrogenated styrene-isoprene-styrene resin, acid-modified styrene-ethylene-propylene-styrene resin A styrene block resin (a) and an epoxy-modified styrene block resin (b) having an epoxy group having an oxirane oxygen concentration of 0.5 to 7% by weight in one molecule are mixed with a carboxyl group or an acid having a mixing ratio of (a). The molar equivalent mixing ratio of the anhydride group and the epoxy group of (b) is 1: 0.5 to 0.5 to 1.
And a good solvent (c) of (a) and (b) which is liquid at room temperature.

The primer composition described above is applied to the surface of a difficult-to-adhesive plastic material or the surface of a metal so as to have a dry film thickness of 1 to 50 μm, and after curing by dry curing, the primer cured coating film is applied. Through, glue,
It is a method for processing a difficult-to-adhere material, which is characterized by painting, lamination, or compounding. More preferably, the difficult-to-adhesive plastic material is one selected from polycarbonate resin, polypropylene resin, and polyacrylic resin, and the primer composition is applied to the surface of a polycarbonate resin lens material sealing portion, and 1
After the primer cured coating film was formed at the same time as drying in an atmosphere of 00 to 150 ° C., the lens member and the lamp housing member were adhesively sealed with a butyl rubber main component-based hot melt sealing agent to obtain a vehicle mounted lamp. Manufacturing is a highly preferred embodiment. Furthermore, the primer composition is applied to a metal surface, and the primer cured coating film is formed simultaneously with drying in an atmosphere of 100 to 150 ° C., and then insert molding is performed to produce a composite material. The above-mentioned method for processing the hardly-adhesive material is a highly preferred embodiment. The present invention will be described in more detail below.

The following primer composition of the present invention comprises P
Primer for adhesion, coating, lamination and compounding of difficult-to-adhere plastic materials represented by C, PEPC, PP, PE, PET and P-MMA and inorganic materials such as glass, ceramics, concrete and metal The composition is a primer composition which can be subjected to composite secondary processing with long-term heat resistance and adhesion durability, especially in an environment exceeding 100 ° C.

The acid-modified styrene block resin (a) in the present invention has a weight average molecular weight in the range of 3,000 to 100,000,
It is preferably in the range of 5,000 to 50,000, more preferably in the range of 1 to 30,000, for example, acid-modified hydrogenated styrene-butadiene resin, acid-modified hydrogenated styrene-butadiene-styrene resin, acid-modified styrene-ethylene-butylene. 1 selected from styrene resin, acid-modified hydrogenated styrene-isoprene resin, acid-modified hydrogenated styrene-isoprene-styrene resin, acid-modified styrene-ethylene-propylene-styrene resin
It is a species or a mixture of two species. The acid-modified styrene block resin (a) is more specifically a hydrogenated styrene-butadiene resin, a hydrogenated styrene-butadiene-styrene resin,
Styrene-ethylene-butylene-styrene resin, hydrogenated styrene-isoprene resin, hydrogenated styrene-isoprene-
Typical examples include those obtained by acid-modifying a styrene block copolymer such as styrene resin and styrene-ethylene-propylene-styrene resin by a known method, and there is no particular limitation, and for example, the styrene block copolymer may be a solution or a block. A typical example is one in which a carboxyl group or an acid anhydride group is introduced into the molecular chain by graft-polymerizing the following unsaturated carboxylic acid monomer under the state.

The above-mentioned hydrogenated styrene-butadiene resin,
Hydrogenated styrene-butadiene-styrene resin, hydrogenated styrene-isoprene resin, hydrogenated styrene-isoprene-styrene resin may be partially hydrogenated or fully hydrogenated intramolecular double bond, Styrene content in each block copolymer is 10 wt% or more and 50 wt%
It is preferably within the following range.

Examples of the unsaturated carboxylic acid monomer include maleic anhydride, maleic acid or its half-esterified products, itaconic anhydride, itaconic acid or its half-esters, crotonic acid, isocrotonic acid and citraconic anhydride. can give. A highly preferable example is one obtained by graft-polymerizing an unsaturated carboxylic acid monomer in an amount of about 0.2 to 10% by weight, preferably 1 to 3% by weight, with respect to the styrene block copolymer, since it is easily available on the market. Is. As well-known and commercially available products, typical examples include Shell Chemical Co.'s product "Clayton G-1901" and Asahi Kasei's product "Tuftec M-1913, M-1943".

The epoxy-modified styrene block resin used as the component (b) of the present invention is a block copolymer,
The double bond derived from the conjugated diene compound of the partially hydrogenated block copolymer is epoxidized, and the base block copolymer is a polymer mainly containing at least one aromatic vinyl compound. Block A and polymer block B mainly composed of at least one conjugated diene compound
And a block copolymer consisting of, for example, AB
A-B-A, B-A-B-A, (A-B-) _4- Si,
It is an aromatic vinyl compound-conjugated diene compound block copolymer having a structure such as ABA-BAA. The partially hydrogenated block copolymer is obtained by hydrogenating the block copolymer. The block copolymer and partially hydrogenated block copolymer will be described in more detail below.

This block copolymer contains an aromatic vinyl compound in an amount of from 5 to less than 95% by weight, preferably from 10 to 60% by weight, more preferably from 10 to 50% by weight, and mainly containing an aromatic vinyl compound. The block A has a structure of a homopolymer block of an aromatic vinyl compound or a copolymer block of an aromatic vinyl compound and a conjugated diene compound containing more than 50% by weight and preferably 70% by weight or more of an aromatic vinyl compound. The polymer block having a conjugated diene compound as a main component has a homopolymer block of a conjugated diene compound or a conjugated diene compound.
It has a structure of a copolymer block of a conjugated diene compound and an aromatic vinyl compound, which is contained in an amount of more than 70% by weight and preferably 70% by weight or more. Further, the polymer block A mainly composed of the aromatic vinyl compound and the polymer block B mainly composed of the conjugated diene compound have a distribution of the conjugated diene compound or the aromatic vinyl compound in the molecular chain of each polymer block. May be random, tapered (in which the monomer component increases or decreases along the molecular chain), partially block-shaped, or any combination thereof. A polymer block mainly containing the aromatic vinyl compound When there are two or more polymer blocks mainly containing the conjugated diene compound, the polymer blocks may have the same structure or different structures.

Examples of the aromatic vinyl compound constituting the block copolymer include styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, 1,1.
One or more of diphenylethylene and the like can be selected, and styrene is preferable. Examples of the conjugated diene compound include butadiene, isoprene,
One type or two or more types are selected from 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like, and among them, butadiene, isoprene and a combination thereof are preferable. In the polymer block mainly composed of the conjugated diene compound, the microstructure in the block can be arbitrarily selected. For example, in the polybutadiene block, the 1,2-vinyl bond structure is preferably in the range of 5 to 65%, and particularly, It is preferably in the range of 10 to 50%.

The number average molecular weight of the block copolymer having the above structure is in the range of 5,000 to 1,000,000, preferably 10,000 to 800,000, and more preferably 30,000 to 500,000. Yes, molecular weight distribution [weight average molecular weight (Mw) and number average molecular weight (Mn)
(Mw / Mn)] is 10 or less. Furthermore, the molecular structure of the block copolymer may be linear, branched, radial, or any combination thereof.

The block copolymer may be produced by any method as long as it has the above-mentioned structure. For example,
According to the method described in JP-B-40-23798, an aromatic vinyl compound-conjugated diene compound block copolymer can be synthesized in an inert solvent using a lithium catalyst.

The partially hydrogenated block copolymer is obtained by hydrogenating the above aromatic vinyl compound-conjugated diene compound block copolymer. As a manufacturing method, for example, Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-
Although the method described in Japanese Patent No. 6636 can also be adopted, it was synthesized using a titanium-based hydrogenation catalyst that exhibits particularly excellent weather resistance and heat deterioration resistance of the hydrogenated block copolymer obtained. Most preferred is a hydrogenated block copolymer,
For example, Japanese Patent Laid-Open Nos. 59-133203 and 60
-Synthesis of a hydrogenated block copolymer by hydrogenating the block copolymer having the above-mentioned structure in the presence of a titanium-based hydrogenation catalyst in an inert solvent by the method described in JP-A-790005. You can At that time, the aliphatic double bond based on the conjugated diene compound of the aromatic vinyl compound-conjugated diene compound block copolymer is 0 to 99% hydrogenated, preferably 0 to 70% hydrogenated. . These block copolymers and partially hydrogenated block copolymers are on the market and can be easily obtained.

Next, the epoxy-modified styrene block resin used as the component (b) of the present invention is prepared by reacting a block copolymer or partially hydrogenated block copolymer having the above-mentioned structure with an epoxidizing agent to give a conjugated diene. It is an epoxidized aliphatic double bond based on a compound. The epoxy-modified styrene block resin used in the present invention can be obtained by reacting the above block copolymer or partially hydrogenated block copolymer with an epoxidizing agent such as hydroperoxides and peracids in an inert solvent. it can. As a peracid, a mixture of formic acid, peracetic acid and perbenzoic acid with hydrogen peroxide, or an organic acid with hydrogen peroxide, or molybdenum hexacarbonyl with tertiary butyl hydroperoxide to obtain a catalytic effect. You can Also, the optimum amount of epoxidizing agent can be determined by such variables as the particular epoxidizing agent used, the degree of epoxidation desired, the particular block copolymer used, and the like. The obtained epoxy-modified styrene block resin can be isolated by a suitable method, for example, a method of precipitating with a poor solvent, a method of adding the polymer to hot water under stirring and distilling off the solvent, or a direct desolvation method. And so on.

The degree of epoxidation of the epoxy-modified styrene block resin as the component (b) is not particularly limited, but the oxirane oxygen concentration is 0.1% by weight to 7% by weight, preferably 1.0% by weight to 5% by weight. % Or less.

The reason for setting the weight average molecular weight of the acid-modified styrene block resin (a) or the epoxy-modified styrene block resin (b) in the range of 3,000 to 100,000 is the storage stability of the solution using the good solvent (c). It is preferable because the melt viscosity can be optimized, workability is excellent, and a desired cured film can be formed. On the other hand, if the weight average molecular weights of (a) and (b) are less than 3,000, the toughness of the cured coating is low, which is a problem. If it exceeds 100,000, the solid content of the primer composition is high. This is because it becomes a viscous system and lacks workability, and therefore the solid content is unavoidably low, so that its practicality is extremely poor.

In the present invention, the acid-modified styrene block copolymer resin (a) and the epoxy-modified styrene block resin (b) are mixed in the respective mixing ratios.
It is prepared so that the molar equivalent mixing ratio of the carboxyl group of (a) or the epoxy group of the acid anhydride group (b) is 1: 0 to 0.5-1 and particularly preferably 1: 1. In addition, it is important that the good solvent (c) of (a) and (b) is made liquid at room temperature. By using the above proportions, a tough cured coating can be formed on the surface of the poorly-adhesive plastic material, and the heat-resistant adhesion reliability under the environment of 100 ° C., which is the object of the present invention, can be achieved for a long time. When the mixing ratio is other than the above, the thermosetting coating remains in a softened state,
Although the adhesiveness is excellent, the heat-resistant cohesive force is insufficient, and it is particularly difficult to secure the effect of preventing interfacial foaming and the reliability of heat-resistant adhesion.

The primer composition of the present invention may be prepared by dissolving the above (a) and (b) separately in a good solvent (c) and mixing them in the above ratio immediately before use. The method is not particularly limited.

There is no problem in using the primer composition of the present invention by appropriately containing the tackifier, oil component, curing cocatalyst, coupling agent and the like described below, if necessary. For example, the composition of the primer liquid of the present invention is 40% by weight or less of the following tackifier and 10% by weight or less of the following oil component in terms of solid content,
Use a coupling agent represented by a silane coupling agent or a titanate type coupling agent in terms of solid content within 2% by weight, and use a known amine as an epoxy type liquid curing co-catalyst such as a tertiary amine or a salt thereof, or a borofluoride. Acid salts, phosphines and organometallic complexes may be used within 0.5% by weight.

The tackifier may be polymerized rosin, rosin ester, C ₅ petroleum resin, dicyclopentadiene petroleum resin, terpene petroleum resin, hydrogenated resin thereof, low molecular weight styrene resin or low molecular weight α. It is preferable to use one or more selected from methylstyrene resins and the like, and particularly preferably, the (hydrogenated) rosin ester resin or the (hydrogenated) petroleum resin-based tackifier has a softening point temperature of 85. It is better to be ℃ or more. As the oil component, it is preferable to use one or more selected from naphthene oil, paraffin oil, liquid polybutene, liquid hydrogenated polyisoprene, decalin and tetralin.

The main purpose of the solvent used in the primer composition of the present invention is to make the primer coating film as thin as possible. Therefore, there is no particular limitation so that the primer composition of the present invention becomes liquid at room temperature, but for example, the solid content is 5 to 80% by weight, preferably 10 to 20% by weight, as follows. It is preferable to dilute it with a solvent to obtain a uniform solution. Preferred solvents include, for example, acetone, methylethylketone, methylisobutylketone, cyclohexanone, isophorone, acetylacetone, acetophenone and other ketones, alcohols such as cyclohexanol, ethyl acetate, butyl acetate and acetic acid having a boiling point in the range of room temperature to 200 ° C. Esters such as -3-methoxybutyl and ethyl acetoacetate, ethers such as ethylene glycol monobutyl ether and diethylene glycol monomethyl ether, furans such as tetrahydrofuran, methyl chloroform, dichloroethane, 1,1,2-trichloroethane, 1,2, Three
-Halogen compounds such as trichloropropane, 1,1,2,2, -tetrachloroethane, trichloroethylene, benzene, toluene, xylene, styrene, kerosene,
Aromatic hydrocarbons such as mineral spirits, aliphatic hydrocarbons such as n-hexane, n-heptane, n-octane, gasoline and cyclohexane are typical, and one or more of these are selected. It is preferable to use.

When the primer composition of the present invention is used for the above-mentioned difficult-to-adhesive plastic material, it is important to select a solvent composition which does not cause solvent cracks, but it is dried immediately after coating the primer composition. The pretreatment method in which the primer layer is formed by using the above method can be used without particular limitation. In addition, any solvent that can liquefy the components (a) and (b) at room temperature can be basically used,
In that sense, other known solvents can be mixed or used independently, and there is no particular limitation.

In the secondary processing using the primer composition of the present invention, the above-mentioned primer composition is appropriately applied to the surface of the hardly-adhesive plastics material or the inorganic material, and finally 1 to 50. It is important to apply in advance so as to obtain a dry cured film thickness of about micron. There are no particular restrictions on the coating and drying conditions, but approximately 100-
It is a preferable example to form a thermosetting coating film of the primer by curing and drying in the range of 180 ° C., preferably 120 to 150 ° C. for about 10 to 120 minutes.

The secondary processing method of the difficult-to-adhere plastics material, which has been subjected to adhesion, coating, lamination or production of a composite through this cured coating, will be described more specifically. The primer composition of the present invention may be prepared, for example, from PC, PP,
In a preferred embodiment, the composition is applied to the surface of a difficult-to-adhere plastics material such as P-MMA, dried and cured, and then a polyolefin hot melt adhesive or various coatings are adhered and shaped through the primer thermosetting coating film. is there.

Generally, the difficult-to-adhere plastics material occupies an important position as an engineering plastic, and is often used, for example, as a lamp constituent member or bumper of an automobile. Moreover, in the same field, as mentioned in the problem to be solved by the invention, the PC or P-MMA lens member and the PP housing member are produced by a method of joining and sealing with a butyl rubber-based hot-melt sealing material composition, In the conventional production lamp using the polycarbonate lens resin material, when exposed to an environment of 100 ° C or higher, a remarkable PC interface foaming phenomenon was observed, resulting in poor sealing.
As a result, there was a serious problem that water leaked into the lamp. The ability to solve this problem is a major feature of the above-mentioned processing method using the primer composition of the present invention. That is, as a construction method capable of satisfying the high-temperature sealing property of an automobile lamp, particularly at 100 ° C. or higher, the primer composition of the present invention is applied to a sealing portion of a PC material, and the cured film thickness is about 1 to 20 μm. As described above, the object can be achieved by curing and drying in the range of 120 to 160 ° C. and then sealingly joining the housing member with a butyl rubber-based hot melt sealing agent which has been conventionally used.

Similarly, with the primer composition of the present invention, the same function and effect as described above are exhibited even in the secondary processing of coating on the surface of the PC or P-MMA material. Further, the primer composition of the present invention is previously applied to a metal surface such as a galvanized steel plate, aluminum, a stainless steel plate, a tin plate, and a steel plate, which is a typical metal, and after drying and baking curing, a polypropylene molding resin or acrylonitrile-butadiene-styrene is used. A preferable processing method is a secondary processing method of insert-molding a steel plate member with a molding resin.

The method for applying the liquid primer composition of the present invention is not particularly limited, but may be brush application, spray application, bar coder application, applicator application, or the like, and any method that can be applied thinly can be preferably adopted. . Although there is no particular limitation, the coating thickness is usually 10 to 150 μm, preferably 10 to 50 μm. The cured dry film thickness is preferably 1 to 20 μm. The method for dry baking the liquid primer composition of the present invention is, for example, far infrared heating, hot air drying, vacuum heating drying, etc., and usually 5
The coating film is formed by heating and drying in the temperature range of 0 to 150 ° C., preferably 120 to 160 ° C., and drying for about 5 to 30 minutes.

With respect to the adhesion processing method in the secondary processing after applying the liquid primer composition of the present invention and forming a cured film, there are conventionally known adhesion processing methods, for example, JP-A-60-92379 and JP-A-62-62.
No. 129373, No. 62-227987,
Butyl rubber-based hot melt compositions disclosed in JP-A No. 62-223287, and other butyl chloride rubber-based partially vulcanized hot melt adhesives, hydrogenated styrene-based block copolymer main component type sealants, moisture-curable Includes processing methods such as adhesion of difficult-to-adhere plastics to each other or to different types of other materials using so-called hot-melt adhesives such as reactive hot-melt adhesives, UV-curable hot melts, electron beam-curable hot melts, etc. To do.
In addition, in the adhesion processing method in the secondary processing after applying the liquid primer composition of the present invention and forming the cured film, the metal used in manufacturing the composite material with the metal by the metal insert molding of the conventional thermoplastic molding resin. Processing means using the primer composition of the present invention as a thermosetting primer coating for surface treatment,
It is also included as a method for processing the hardly-adhesive plastics of the present invention. That is, the processing method for the hardly-adhesive plastic material of the present invention means, as described above, the secondary processing such as the adhesion processing, the coating processing, the lamination processing and the composite processing which are carried out through the primer composition of the present invention. Included in the processing method.

[0034]

EXAMPLES Examples of the present invention will be described below.
Parts and% mean parts by weight and% by weight, and the examples do not particularly limit the present invention. The interface foaming test described in the examples was performed by the following test method.

(Interfacial Foaming Test) PC, a polyacrylic resin plate having a thickness of 2 mm and 5 cm × 10 cm was prepared, and the primer composition described in the example was applied to one surface thereof using a bar coater and immediately at 130 to 140 ° C. Was subjected to a dry baking treatment for 15 minutes by a hot air dryer to obtain treated test pieces each having a film thickness of 5 μm. On the other hand, a separately prepared polypropylene resin (hereinafter abbreviated as PP) or acrylonitrile-butadiene-styrene resin (hereinafter abbreviated as ABS) having a thickness of 2 mm and a size of 2 cm × 10 cm flat plate, the hot melt type sealing material described in the example at 190 ° C. Width 6-8mm, length 5cm using handgun at application temperature
Was applied in the form of beads. Immediately, the above-mentioned primer-treated test piece, untreated PC, and the same polyacrylic resin test piece were used as the former on the primer-coated surface and the latter on the untreated surface.
The hot-melt adhesive was attached to a thickness of 1 mm, left in an atmosphere of 25 ° C / RH85% for 24 hours or more, and then left in a 130 ° C constant temperature bath for 8 to 72 hours, and then taken out. It was determined whether foaming was visually observed.

(Adhesion test) A primer composition described in the examples was applied to a flat test piece of PC, polyacrylic resin having a thickness of 2 mm, 10 cm × 10 cm, and immediately dried and baked at 130 ° C./15 minutes. The obtained primer-treated test piece was placed in a thermo-hygrostat at 50 ° C / RH85% for 24 hours.
It was left for a time, taken out, and a cellophane tape was brought into close contact with the coated surface, and pulled at an angle of 45 degrees to measure the adhesiveness.

(Reference Example 1: Preparation of hot-melt type sealing material (1) used in Examples) Using a kneader-ruder apparatus having a capacity of 10 liters, butyl rubber (trade name "Butyl 065", Nippon Butyl Products)
900 parts and styrene-ethylene-butylene-styrene block copolymer (trade name "Clayton G1657
X ", shell chemical product) 800 parts, hydrogenated petroleum resin as a tackifier (trade name" Clearon P-125 ", Yasuhara Yushi Products) 1,300 parts, also" ESCOLETS 532 "
0 "(product of Tonex Co., Ltd.) 700 parts, polypropylene wax as a wax component (product name" Viscor 660P ", Sanyo Chemical Product) 200 parts, liquid polybutene as a plasticizer (product name" HV-300 ", Nippon Petrochemical Product) ) 350 parts, titanium oxide 50 parts, carbon black 0.5 part, atactic polypropylene (hereinafter referred to as APP, a product of Mitsui Toatsu Chemicals, Inc.) 500 parts, and bis (2,2,6,6-tetramethyl) -4-piperidyl) sebacate 25 parts, pentaerythrityl-tetrakis [3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate] 50 parts, 2- [2-hydroxy-
3,5-bis (α, α-dimethylbenzyl) phenyl]
After 25 parts of benzotriazole was uniformly melt-kneaded, it was completely defoamed under vacuum to obtain a gray hot-melt type sealing material (1). The melt viscosity of this product at 190 ° C is 9
It was 9,000 centipoise (B type viscometer). Also, it has almost no fluidity at 90 ° C and has a softening point of 137 ° C.
(Ring and ball method).

Reference Example 2: Preparation of Hot Melt Sealing Material (2) Used in Examples A styrene-isoprene-styrene block copolymer (commercial product) was used at a temperature of 140 to 170 ° C. using a kneader-ruder apparatus having a capacity of 10 liters. Name "Califlex TR-1107", shell chemical product) 750 parts, also "Califlex TR-111
1 "(shell chemical product) 500 parts, hydrogenated petroleum resin as a tackifier (trade name" Alcon P-125 ", Arakawa chemical product) 1,500 parts, also the trade name" ESCOLETS 5320 "(Tonex product) 600 Department, also "Product Name YS Polystar T-130" (Yasuhara Yushi Products)
250 parts, 250 parts of trade name "Viscole 660P" (Sanyo Chemical Co., Ltd.), 100 parts of trade name "High Wax 600P" (Sanyo Petrochemical), naphthenic oil as plasticizer (trade name "Flex # 2"
050N ", Fuji Kosan product) 350 parts, carbon black 2 parts, and octadecyl-3- (3,3 as an antioxidant.
50 parts of 5-di-t-butyl-4-hydroxyphenyl) propionate, 20 parts of tris (2,4-di-t-butylphenyl) phosphite and "APP-L grade" (product of Mitsui Toatsu Chemicals, Inc.) ) 628 parts were uniformly melted and kneaded and then completely defoamed under vacuum to obtain a black hot-melt type sealing material (2). 170 ℃ of this thing
Has a melt viscosity of 59,000 centipoise (B-type viscometer)
Met. Further, there was almost no fluidity at 80 ° C, and the softening point was 127 ° C (ring and ball method).

(Examples 1 to 4 and Comparative Examples 1 to 3) Table-
A liquid primer composition was prepared at the blending ratio (parts by weight) shown in Examples 1 to 3 described in 1 and used for the test.

[0040]

[Table 1]

Liquid primer compositions were prepared at the compounding ratios (parts by weight) shown in Comparative Examples 1 to 3 shown in Table 2.

[0042]

[Table 2]

(Description of symbols in Tables 1 and 2) M-1943: 3% maleic anhydride graft-modified styrene-ethylenebutylene-styrene resin "Asahi Kasei product:
Tuftec ", the weight average molecular weight was estimated to be 40,000 to 60,000 in terms of polystyrene by gel permeation chromatography measurement. G-1901X: Maleic anhydride 3% graft-modified styrene-ethylenebutylene-styrene resin "Shell Chemical Co. product: Kraton", the weight average molecular weight was estimated to be about 50,000 in terms of polystyrene by gel permeation chromatography measurement. . G-1650: Unmodified styrene-ethylene butylene-
The weight average molecular weight of the styrene resin "Shell Chemical Co., Ltd .: Clayton" was estimated to be about 10 to 130,000 in terms of polystyrene by gel permeation chromatography. Epoxy-modified block copolymer: partially hydrogenated styrene-
A butadiene block copolymer (styrene / butadiene weight ratio = 3/7, hydrogenation rate 30%) epoxidized with peracetic acid is used as an epoxy-modified block copolymer. The oxirane oxygen concentration of this epoxy-modified block copolymer was 4.15% by weight. Epoxy-modified block copolymer: partially hydrogenated styrene-
A butadiene block copolymer (styrene / butadiene weight ratio = 3/7, hydrogenation ratio 80%) epoxidized with peracetic acid is used as an epoxy-modified block copolymer. The oxirane oxygen concentration of this epoxy-modified block copolymer was 3.04% by weight.

Cellotape adhesion test results on polycarbonate resin and polyacrylic resin, which were carried out using the respective primer compositions obtained in Examples 1 to 4 and Comparative Examples 1 and 2, and adhesion using a hot melt sealing material. The test results are shown in Table 3.

[0045]

[Table 3]

(Symbols in Table 3) * 1: The adhesion test was based on a cross cut / cellophane tape peeling test. ⊚ indicates no peeling, and ◯ indicates peeling within 5%. * 2: The interfacial foamability test was carried out by bonding using the hot melt type sealing material (1). * 3: The interfacial foamability test was carried out by bonding using the hot melt type sealing material (2). The symbols for the interface foamability test are as follows: ◎ indicates no foaming, ○ indicates heating for 48H
After rs, a very slight interfacial bubbling phenomenon was observed, Δ indicates that the interfacial bubbling phenomenon was slightly observed from the initial stage, and x indicates that a large number of interfacial bubbling phenomena were observed from the initial stage of the test. PC: Polycarbonate resin, PP: Polypropylene resin, Acrylic: Polymethylmethacrylate resin, ABS:
Acrylonitrile-butadiene-styrene copolymer resin.

(Example 5) A hemispherical convex lens type PC lens material having a thickness of 3 mm and a diameter of 200 mm and a dedicated housing material made of PP having a U-shaped adhesive seal structure, which is used as a vehicle lamp. Was prepared, and the primer B composition of Example 2 was spray-applied to the PC seal foot portion, and a PC member was prepared in advance so that a dried / cured film thickness of 130 ° C./20 minutes was 5 μm. After that,
Hot-melt type sealing material (1) heat-melted at 190 ° C
Was discharged to the U-shaped seal portion of the PP housing member, and the PC seal foot portion was inserted and joined at an oven time of 1 minute and a set time of 30 seconds. As a result, the U-shaped tensile shear strength in an inch width normally obtained a value of 25 kg / cm ² ,
After heat curing test after heating at 130 ° C for 2 hours, the strength is 2
It showed ² kg / cm ² . It was also confirmed that problems such as the PC interface foaming phenomenon did not occur even in a continuous environment test at 115 ° C / 1 day and night, and it was confirmed that the lamp has excellent heat-resistant seal reliability characteristics. The lamp of the present embodiment is water resistant, 100
No water leakage at all in tests such as thermocycles at ℃ / 1,000 hours, -40 ℃ / 4 hours, 80 ℃ / 4 hours.
It had excellent adhesive seal reliability.

Comparative Example 3 A lamp obtained in the same manner as in Example 5 except that the primer E of Comparative Example 2 was used in place of the primer B, or any lamp obtained without application of a primer was 115 ° C. 1 hour heat resistance test and 130 ℃
It was observed that the PC interface foaming occurred in the heat resistance test for / 10 minutes, and further foaming further grew when the test was continued. The adhesion reliability value obtained in the same manner as in Example 1 was reduced to -45% or more of the normal state in terms of the strength change rate, and the reliability of shear peel strength was also decreased.

(Embodiment 6) A 0.5 mm thick 5 mm square stainless steel plate and the primer A of Embodiment 1 were further used as a 0.5% glycidoxysilane coupling material in terms of solid content, and a silane coupler manufactured by Shin-Etsu Chemical Co., Ltd. Brush the primer composition to which KBM-403 was added, and apply 180 ° C /
It was dried by heating for 15 minutes to form a thermosetting film. The primer-treated steel sheet was set in a mold, and the following injection / extrusion molding was carried out so that the primer surface could be coated with a thermoplastic PP molding resin (Mitsui Noblene) having a thickness of 3 mm. Injection pressure is 5-8kg / cm ² and gate opening diameter is 5m
It was carried out at a PP resin discharge temperature of 230 ° C. by using an apparatus and a mold capable of composite-forming a coating film on a metal surface having three m diameters within 15 seconds. As the compound for PP molding resin, a resin pellet containing 55% of trade name: Mitsui Lebren and 45% in total of other components such as calcium carbonate, 1 mm long mineral fiber, and titanium white was used. After injection molding, it was taken out of the mold and the cross section was cut with a grinder at room temperature.As a result, no peeling phenomenon was observed, and the solid microscope observation showed that the cured primer film was firmly bonded to the interface between the metal and the molding resin. Was done.

Comparative Example 4 A metal complex was prepared in the same manner except that the primer F used in Comparative Example 2 was used instead of the primer composition used in Example 6. As a result, the interfacial peeling phenomenon was observed as a result of cutting the composite with a grinder at room temperature. In addition, in the observation with a stereomicroscope, no primer was present near the metal interface. It seems that almost all of the discharged resin exhibited a melt flow, and there was no primer at the local site centering on the gate, and the composite adhesion reliability could not be secured.

(Example 7) In place of the PP molding resin used in Example 6, talc and colloidal silica, carbon black, etc. containing 30% or less in total of the molding thermoplastic resin "Santac" of Mitsui Toatsu products were used. A composite material was obtained in the same manner except that the pellets were mixed with the filler. As a result of cutting the composite material with a grinder at room temperature, no peeling phenomenon was observed at all, and as a result of observation with a stereoscopic microscope, a state in which a hardened primer film was firmly bonded to the interface between the metal and the molding resin was observed.

[0052]

EFFECT OF THE INVENTION The primer composition of the present invention can form a strong thermosetting film while exhibiting excellent adhesion properties especially to polycarbonate resin and polyacrylic resin material, which are said to be difficult to adhere to. The effect of forming the primer coating is 1 as shown in Examples 1 to 4.
It has been found that even in an environment of 00 ° C. or higher, there is no interfacial bubbling phenomenon, and the primer has a long-term heat-resistant adhesive reliability. Further, as revealed in Examples 5 and 6, in the field of processing methods of automobile lamps and the field of composite processing with metal, which have been practically problematic in the past, they exhibit excellent effects that have not been achieved in the past. It has been found that a secondary processing method using the primer composition of the present invention is achieved. Particularly in the production of automotive lamps, there is a great practical feature that the already known butyl rubber-based hot melt sealing material having excellent weather resistance, heat aging resistance, toughness, heat resistance and the like can be used as it is as a sealing material. Therefore, the significance of the present invention is great. Further, the present invention can be widely applied not only to the sealing processing of the above-described plastic lamp for a vehicle, but also to the field of composite bonding of a polycarbonate disk substrate or an acrylic optical disk substrate, and can be used in a wide range of bonding processing fields. It is a thing.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C09J 5/02 JGP C09J 5/02 JGP

Claims (7)

[Claims] 1. An acid-modified styrene block resin (a) having a weight average molecular weight in the range of 3,000 to 100,000, and an oxirane oxygen concentration of 0.1% in one molecule having a weight average molecular weight in the range of 3,000 to 100,000. An epoxy-modified styrene block resin (b) having 5 to 7% by weight of an epoxy group and a carboxyl group or an acid anhydride group having a mixing ratio of (a) and (b), respectively.
In molar equivalent mixing ratio with the epoxy group of 1: 0.5-0.
A primer composition, characterized in that it is blended in a ratio of 5: 1 and is made liquid at room temperature with a good solvent (c) of (a) and (b). 2. An acid-modified styrene block polymer (a)
Is an acid-modified hydrogenated styrene-butadiene resin, an acid-modified hydrogenated styrene-butadiene-styrene resin, an acid-modified styrene-ethylene-butylene-styrene resin, an acid-modified hydrogenated styrene-isoprene resin, an acid-modified hydrogenated styrene-isoprene- The primer composition according to claim 1, which is one kind or a mixture of two or more kinds selected from styrene resin and acid-modified styrene-ethylene-propylene-styrene resin. 3. An oxirane oxygen concentration of 0.5 to 1 molecule.
The epoxy-modified styrene block resin (b) having 7% by weight of epoxy group is (partially hydrogenated) styrene-butadiene resin, (partially hydrogenated) styrene-butadiene-styrene resin, (partially hydrogenated) styrene-isoprene resin, ( (Partially hydrogenated) The primer composition according to claim 1, which is obtained by epoxidizing a two-bond bond derived from a conjugated diene compound of one kind or a mixture of two or more kinds selected from styrene-isoprene-styrene resin. 4. The primer composition according to claim 1 is applied to the surface of a difficult-to-adhesive plastic material or a metal surface in advance so as to have a dry film thickness of 1 to 50 μm, and the primer is dried and cured to obtain the primer. Through the cured coating,
A method for processing a hard-to-bond material, which comprises subjecting it to a process of bonding, painting, lamination or compounding. 5. The method for processing a difficult-to-bond material according to claim 4, wherein the hard-to-bond plastic material is one selected from a polycarbonate resin, a polypropylene resin and a polyacrylic resin. 6. The primer composition according to claim 1 is applied to the surface of a polycarbonate lens material sealing portion,
After forming the primer cured coating film at the same time as drying in an atmosphere of 100 to 150 ° C., the lens member and the lamp housing member are adhesively sealed with a butyl rubber main component-based hot melt sealing agent to obtain a vehicle mounted lamp. The method for processing a poorly-adhesive material according to claim 5, which is manufactured. 7. The primer composition according to claim 1 is applied to a metal surface, dried under an atmosphere of 100 to 150 ° C. to form the primer cured coating film, and then insert-molded to form a composite material. 5. The method according to claim 4, wherein
The method for processing the difficult-to-adhere materials described.