JP2004123898A - Method for manufacturing coated molded subject - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-mold coating technique permitting stable uniform coating of a molded subject composed of a crosslinked norbornene polymer. <P>SOLUTION: A mixture comprising a norbornene monomer is injected into a mold comprised of a cavity mold and a core mold and subjected to crosslinking polymerization to give the molded subject and the molded subject is coated by an in-mold coating method, where a two-pack coating comprising a liquid X mainly composed of a colorant and a vehicle component and a liquid Y mainly composed of a curing agent is mixedly injected into the mold. <P>COPYRIGHT: (C)2004,JPO

Description

【００６９】
これらの結果から、本発明では、プライマー処理やサンディングなどの人手のかかる作業工程を省略でき、下塗り塗料の塗装に利用すれば成形後直ちにその上に塗装でき、また使用する塗装の種類も多様化できるインモールドコーティング法の特徴を活かしつつ、インモールドコーティングの制御条件範囲を広げることができ、これにより、均一な塗装を安定的に行うことができることが理解される。
【００７０】
【発明の効果】
本発明により、ノルボルネン系架橋重合体からなる成形物に均一な塗装を安定的に行うことができるインモールドコーティング技術が提供される。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a painted molded article of a norbornene-based crosslinked polymer which is lightweight and excellent in impact resistance.
[0002]
[Prior art]
BACKGROUND ART Norbornene-based crosslinked polymers are widely used in bumpers for automobiles, covers for construction equipment, exterior parts for medical equipment, etc. because of their light weight and high impact resistance. However, the norbornene-based crosslinked polymer has a double bond in the molecular structure, and is discolored with time because it is oxidized. Therefore, the norbornene-based crosslinked polymer is generally used by coating the surface of the polymer.
[0003]
For coating, the norbornene-based cross-linked polymer has a double bond in the molecule, and the coating does not adhere unless a part of it is oxidized and has a polar group. . However, even in such a case, the base of the crosslinked polymer is an olefin, and the coating often peels off when used for a long period of time.
[0004]
Therefore, before coating, a primer is applied, or pre-coating treatment such as sanding is performed. In particular, sanding can partially use a robot, but most of the sanding is manually performed, and fine powder is scattered. Therefore, improvement in economics and hygiene is desired.
[0005]
Therefore, an in-mold coating method has been proposed (for example, see Patent Documents 1 and 2). In this in-mold coating method, labor-intensive work steps such as primer treatment and sanding can be omitted, and if used for applying an undercoat, it can be applied immediately after molding, and the types of coating used can be diversified.
[0006]
[Patent Document 1]
JP 2001-71345 A (paragraph numbers 0017 to 0023)
[0007]
[Patent Document 2]
JP-A-11-300776 (paragraph number 0005)
[0008]
[Problems to be solved by the invention]
However, since the norbornene-based crosslinked polymer is usually molded in a cavity mold temperature range of about 65 ° C. to 95 ° C., the curing of the in-mold coating paint is completed within a few minutes at the above temperature. Is selected. Usually, under such conditions at which curing at a low temperature is possible, the pot life becomes extremely short, and the paint gels in the injection device, which is not preferable.
[0009]
In order to extend pot life and achieve fast curing at low temperatures, it is necessary to sharpen the temperature dependence of the curing speed, but such paints are difficult to obtain at low cost, and even if available, Uniform coating is difficult due to the temperature distribution in the mold.
[0010]
An object of the present invention is to solve the above problems and to provide a technique capable of stably performing uniform coating by expanding a control condition range of in-mold coating.
[0011]
Still other objects and advantages of the present invention will become apparent from the following description.
[0012]
[Means for Solving the Problems]
According to one aspect of the present invention, a mixture containing a norbornene-based monomer is injected into a mold composed of a cavity mold and a core mold, crosslinked and polymerized to form a molded article, and the molded article is subjected to an in-mold coating method. In a method for producing a coated molded product, a two-pack type paint, a liquid X mainly containing a colorant and a vehicle component and a liquid Y mainly containing a curing agent, is mixed and injected into a mold. The present invention also provides a method for producing a coated molded product.
[0013]
More specifically, it is preferable that the liquid X and the liquid Y are supplied through separate lines, mixed by collision in a paint injection device attached to the mold, and injected into the mold at a pressure of 7 to 34 MPa.
[0014]
Further, as a vehicle component, an unsaturated polyester resin, an epoxy acrylate oligomer, at least one of a group consisting of a polyester acrylate oligomer and a urethane acrylate oligomer, and an ethylenically unsaturated monomer copolymerizable therewith,
As the curing agent, it is preferable to include a polymerization initiator and, in some cases, an accelerator for the polymerization initiator.
[0015]
In the following, "at least one selected from the group consisting of unsaturated polyester resins, epoxy acrylate oligomers, polyester acrylate oligomers and urethane acrylate oligomers" is abbreviated as component (a), and "ethylenic copolymerizable therewith" The vehicle component comprising the unsaturated monomer may be abbreviated as component (b), the polymerization initiator may be referred to as component (c), and the accelerator of the polymerization initiator may be referred to as component (d).
[0016]
Further features of the present invention will be apparent in the embodiments and drawings of the invention described below.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings, tables, examples, and the like. Note that these drawings, tables, examples, and the like, and the descriptions are merely illustrative of the present invention, and do not limit the scope of the present invention. It goes without saying that other embodiments can also belong to the category of the present invention as long as they conform to the gist of the present invention.
[0018]
The norbornene-based crosslinked polymer of the present invention is obtained by polymerizing a compound having at least one norbornene skeleton in a molecule with a catalyst. Then, it can be molded with high dimensional accuracy by reaction injection molding (RIM method, abbreviated to Reaction Injection Molding) or resin transfer molding (RTM, abbreviated as Resin Transfer Molding) in which polymerization and molding are performed simultaneously.
[0019]
As a catalyst, a catalyst based on a metal such as tungsten (W), molybdenum (Mo), or ruthenium (Ru) is known.
[0020]
Since this polymer is a liquid forming material, complicated shapes can be formed relatively inexpensively and easily by the RIM or RTM molding method. In addition, this resin can further improve the impact resistance by adding an elastomer such as styrene-butadiene and ethylene-propylene-diene, or can be reinforced by adding fiber reinforcement such as glass fiber and carbon fiber or glass fine particles. Can be used.
[0021]
The norbornene-based monomer of the present invention is a compound having at least one norbornene skeleton in a molecule. Specific examples include dicyclopentadiene, tricyclopentadiene, cyclopentadiene-methylcyclopentadiene co-dimer, 5-ethylidene norbornene, norbornene, norbornadiene, 5-cyclohexenylnorbornene, 1,4,5,8-dimetano-1,4. , 4a, 5,6,7,8,8a-octahydronaphthalene, 1,4-methano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-ethylidene-1,4 , 5,8-Dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-ethylidene-1,4-methano-1,4,4a, 5,6,7,8 , 8a-octahydronaphthalene, 1,4,5,8-dimetano-1,4,4a, 5,8,8a-hexahydronaphthalene, ethylenebis (5-norvol Emissions) and the like can be illustrated, may also be used a mixture thereof. In particular, dicyclopentadiene or a mixture containing 50 mol% or more, preferably 70 mol% or more thereof is suitably used.
[0022]
Further, if necessary, a metathesis polymerizable cyclic olefin having a polar group containing a different element such as oxygen or nitrogen can be used as a copolymer monomer. Such a copolymer monomer preferably has a norbornene structural unit, and the polar group is preferably an ester group, an ether group, a cyano group, an N-substituted imide group, a halogen group, or the like. Specific examples of such a copolymerized monomer include 5-methoxycarbonylnorbornene, 5- (2-ethylhexyloxy) carbonyl-5-methylnorbornene, 5-phenyloxymethylnorbornene, 5-cyanonorbornene, 6-cyano-1, 4,5,8-Dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, N-butylnadic imide, 5-chloronorbornene and the like can be mentioned.
[0023]
As a catalyst for obtaining the crosslinked polymer of the present invention, a catalyst well-known as a metathesis catalyst system is used, and as a catalyst component, a salt such as a halide or an ammonium salt of a metal such as tungsten, rhenium, tantalum or molybdenum and an activity thereof are used. As an agent component, there can be mentioned a composite catalyst comprising an organometallic compound mainly composed of an alkylated metal of Group I to Group III of the periodic table, in particular, a tetraalkyltin, an alkylaluminum compound, an alkylaluminum halide compound, Alternatively, a catalyst comprising a ruthenium carbene complex may be used.
[0024]
In the former, polymerization is generally performed in a short time by mixing two liquids, a monomer liquid A containing a catalyst component and a monomer liquid B containing an activator component. The latter is generally polymerized by mixing or heating the monomer solution and the catalyst component.
[0025]
In the present invention, when two liquids are mixed and polymerized, the monomer liquid A (solution A) contains a catalyst component of a metathesis polymerization catalyst system. As such a catalyst component, halides or ammonium salts of metals such as tungsten, rhenium, tantalum and molybdenum are used, and a tungsten compound is particularly preferable.
[0026]
As such a tungsten compound, tungsten hexahalide, tungsten oxyhalide and the like are preferable, and more specifically, tungsten hexachloride, tungsten oxychloride and the like are preferable.
[0027]
It has been found that such a tungsten compound immediately starts cationic polymerization when added directly to a monomer, which is not preferable. Therefore, it is preferable that the tungsten compound is used by suspending it in an inert solvent such as benzene, toluene, chlorobenzene or the like in advance and solubilizing by adding a small amount of an alcohol compound and / or a phenol compound.
[0028]
Further, as described above, it is preferable to add about 1 to 5 mol of a Lewis base or a chelating agent to 1 mol of the tungsten compound in order to prevent undesired polymerization. Examples of such additives include acetylacetone, alkyl acetoacetates, tetrahydrofuran, benzonitrile and the like. When a polar monomer is used, as described above, the polar monomer itself may be a Lewis base, and the compound may have the action even without adding the compound as described above. As described above, the monomer liquid A containing the catalyst component (solution A) has substantially sufficient stability.
[0029]
On the other hand, the monomer solution B (solution B) of the present invention contains an activator component of a metathesis polymerization catalyst system. The activator component is preferably an organometallic compound centered on an alkylated metal of Group I to Group III of the periodic table, particularly a tetraalkyltin, alkylaluminum compound or alkylaluminum halide compound. Examples thereof include diethylaluminum, ethylaluminum dichloride, trioctylaluminum, dioctylaluminum iodide, and tetrabutyltin. A monomer liquid B (solution B) is formed by dissolving the organometallic compound as an activator component in a monomer.
[0030]
Basically, by mixing the solution A and the solution B and injecting them into a mold, a crosslinked polymer molded product can be obtained. However, if the above composition is maintained, the polymerization reaction starts very quickly. Therefore, curing may occur while not sufficiently flowing into the mold, which may be a problem. In such a case, it is preferable to use an activity regulator. As such a regulator, Lewis bases are generally used, and above all, ethers, esters, nitriles and the like are used. Specific examples include ethyl benzoate, butyl ether, diglyme and the like. Such a regulator is generally used by adding it to the solution (solution B) of the component of the activator of the organometallic compound. When a monomer having a Lewis base is used as described above, it can also serve as a regulator.
[0031]
The amount of the metathesis polymerization catalyst system used is, for example, when a tungsten compound is used as a catalyst component, the ratio of the tungsten compound to the raw material monomer is about 1,000 to 1 to 15,000 to 1, preferably 2, In the case where alkyl aluminums are used as the activator component, the ratio of the aluminum compound to the raw material monomer is about 100: 1 to 10,000: 1, preferably on a molar basis. A neighborhood of 200: 1 to 1,000: 1 is used. Further, the above-mentioned chelating agent and regulator can be appropriately adjusted and used according to the amount of the catalyst system to be used by experiments.
[0032]
The molded product of the crosslinked polymer in the present invention may further contain various additives according to the purpose in order to improve or maintain its properties in practical use. Such additives include fillers, pigments, antioxidants, light stabilizers, flame retardants, polymer improvers, and the like. Such an additive cannot be added after the crosslinked polymer of the present invention has been formed, and therefore must be added to the above-described raw material solution beforehand.
[0033]
As the easiest method, a method of adding in advance to one or both of the solution A and the solution B can be mentioned. In this case, a strongly reactive catalyst component or an activator in the solution is used. It must not react to some extent with the components in practical use and must not inhibit polymerization. Inevitably, even if the reaction is unavoidable, if it does not substantially inhibit polymerization or does not inhibit polymerization in a short period of time, it is mixed with a monomer to prepare a third liquid, and immediately before polymerization, They can be mixed and used. Alternatively, a method may be considered in which the polymerization catalyst or the activator is used as the third liquid, and the above-described additive is added to the solution A or the solution B containing no third liquid. Further, in the case of a solid filler, both components are mixed, and immediately before the start of the polymerization reaction or during polymerization, a material having a shape capable of sufficiently filling the voids is filled in a mold. It is also possible to put. Further, the molded article according to the present invention is preferably added with an antioxidant, and it is therefore desirable to add a phenolic or amino antioxidant to the solution in advance. Specific examples of these antioxidants include 2,6-di-t-butyl-p-cresol, N, N′-diphenyl-p-phenylenediamine, tetrakis [methylene (3,5-di-t-butyl- 4-hydroxycinnamate)] methane and the like.
[0034]
In the molded article of the present invention, another polymer may be added as an additive in a monomer solution state. As such an additive, an elastomer is effective in increasing the impact resistance of a molded product and adjusting the viscosity of a solution. Examples of the elastomer used for this purpose include a wide range of elastomers such as styrene-butadiene-styrene triblock rubber, styrene-isoprene-styrene triblock rubber, polybutadiene, polyisoprene, butyl rubber, ethylene propylene-diene terpolymer, and nitrile rubber. Can be.
[0035]
In the molding method of the present invention, a mixture of a norbornene-based monomer component and a catalyst-based component (including an activator, if present) is injected into a mold composed of a cavity mold and a core mold, and polymerized. Let me know. Usually, a temperature difference is provided between the two molds. This is because the molded product adheres to the high-temperature mold side, and the sink marks caused by shrinkage concentrate on the low-temperature mold side and do not appear on the high-temperature mold side. Plays a role in forming the design surface (the surface that requires aesthetics). The mold temperature is 25 to 120 ° C., and the temperature difference between the molds is generally 5 to 100 ° C., but the mold temperature on the side to be the design surface of the molded article is 40 to 120 ° C., while the molded article is The mold temperature on the back side of the mold is preferably 25 to 85 ° C, and the temperature difference between the molds is preferably 20 to 85 ° C.
[0036]
Examples of the material of the mold include casting or thermal spraying of steel, cast or forged aluminum or zinc alloy, electroforming of nickel or copper, and resin.
[0037]
In the in-mold coating method of the present invention, at the stage where the cross-linking of the molded product has sufficiently proceeded, that is, at the stage when the surface of the molded product can withstand the injection pressure of the paint and the flow pressure, the paint provided on the mold by the injector From the inlet, paint is poured into the mold. Usually, the design surface of the molded product is a mold on the high-temperature side and is a painted surface.
[0038]
The injection pressure of the paint is 3-44 MPa, preferably 7-34 MPa. If it is less than 3 MPa, the paint does not sufficiently penetrate and flow between the mold and the surface of the molded product. Conversely, if it exceeds 44 MPa, it is necessary to strengthen the paint injection equipment and increase the strength of the mold.
[0039]
After injecting the paint, the mold may be kept in the state at the time of molding, or the mold clamping pressure may be increased, in order to allow the paint to sufficiently adhere to the molded product and cure. The curing time of the paint is usually 20 seconds to 10 minutes, preferably 60 seconds to 4 minutes. If the time is shorter than 20 seconds, the coating is insufficiently cured, and if the time is longer than 10 minutes, the productivity is poor.
[0040]
The paint used in the present invention is a two-pack type paint comprising a liquid X containing a coloring agent and a vehicle component as main components and a liquid Y containing a curing agent as a main component.
[0041]
The vehicle component preferably contains component (a) and component (b). The curing agent is an agent for crosslinking and polymerizing the vehicle, and preferably contains the component (c) and, if necessary, the component (d).
[0042]
The two liquids are supplied to the paint injection device attached to the mold on separate lines, are impact-mixed in the injection device, and are injected from the injection port between the cavity mold and the molded product.
[0043]
Note that the liquid X and the liquid Y may contain other chemicals as long as they do not contradict the purpose of the present invention. For example, a modifying resin may be added as a bulking agent or a viscosity adjusting agent in order to increase the compatibility between the liquid X and the liquid Y. Examples of the modified resin include polymethyl methacrylate, polyvinyl acetate, saturated polyester, and chlorinated polyolefin.
[0044]
Using a paint injection device having the same function as the injection device used for injection mixing of the monomer liquids A and B, the liquid X and the liquid Y are coated as if they were the same as the monomer liquids A and B for forming the molded article. By adjusting the mixing ratio in the injection device and mixing, the curing speed can be selected regardless of the pot live of the paint, so that the productivity and the uniformity can be improved. However, the injection amount ratio between the liquid X and the liquid Y does not need to be the same.
[0045]
Each of the components (a) has an unsaturated double bond in the molecule, and starts a curing reaction with the component (b) due to active radicals generated by thermal decomposition of, for example, an organic peroxide as a polymerization initiator. However, as a result of this active radical reacting with the unsaturated bond remaining in the norbornene-based crosslinked polymer (molded product), the molded product and the paint are chemically bonded, and it is supposed that strong adhesion of the paint is exhibited. .
[0046]
Particularly preferred component (a) comprises an epoxy acrylate oligomer or a urethane acrylate oligomer or an unsaturated polyester resin.
[0047]
Examples of the ethylenically unsaturated monomer as the component (b) include styrene, α-methylstyrene, chlorostyrene, vinyltoluene, divinylbenzene, methyl (meth) acrylate, 1,6-hexanediol diacrylate, and tripropylene glycol diacrylate. Acrylate, trimethylolpropane tri (meth) acrylate, silicon acrylate, silicon diacrylate and the like can be mentioned. The amount of the ethylenically unsaturated monomer is preferably 20 to 200 parts by weight, more preferably 40 to 160 parts by weight, per 100 parts by weight of the component (a).
[0048]
As the polymerization initiator (component (c)) for crosslinking and polymerizing the vehicle component, an organic peroxide is preferable. Specific examples thereof include bis (4-t-butylcyclohexyl) peroxydicarbonate, lauroyl peroxide, t-amylperoxy-2-ethylhexanoate, benzoyl peroxide, and t-butylperoxy-2-ethyl. Hexanoate and the like can be mentioned.
[0049]
The compounding amount of the component (c) to be impact-mixed in the paint injection device is preferably 0.1 to 15 parts by weight based on 100 parts by weight of the total of the component (a) and the component (b).
[0050]
The polymerization initiator accelerator (component (d)) is used to promote rapid activation of component (c). Examples of the promoter include, but are not limited to, cobalt naphthenate, cobalt octylate, zinc naphthenate, zinc octylate, manganese naphthenate, lead naphthenate, or a mixture thereof. . Sometimes not used.
[0051]
The addition amount of the component (d) is preferably 0.01 to 20 parts by weight based on 100 parts by weight of the total of the component (a) and the component (b).
[0052]
The colorant used in the present invention includes pigments and / or dyes, and may further contain a releasing agent, a polymerization inhibitor, an ultraviolet absorber, a light stabilizer, a surface conditioner, and the like, if necessary. Is also good. These chemicals may be directly contained in the liquid X or the liquid Y instead of the coloring agent, as long as they do not contradict the spirit of the present invention.
[0053]
【Example】
Next, examples and comparative examples of the present invention will be described in detail. The evaluation was based on the following method.
[0054]
(Painting durability test)
According to the method described in JIS K5400, a grid test of 1 mm square was performed. Cut lines at 1 mm intervals were provided on the surface by 10 lines in the vertical and horizontal directions to prepare 100 grids, and when the adhesive tape was peeled off, the number of grids not peeled was shown. The primary adhesion indicates the initial characteristics, and the secondary adhesion indicates the characteristics after immersion in 50 ° C. hot water for 7 days.
[0055]
[Reference Example 1]
(Preparation of solution A)
28 parts by weight of tungsten hexachloride were added to 80 parts by weight of dry toluene under a nitrogen stream, then a solution of 1.3 parts by weight of t-butanol dissolved in 1 part by weight of dry toluene was added and stirred for 1 hour. A solution consisting of 14 parts by weight of toluene and 14 parts by weight of toluene was added, and the mixture was stirred for 5 hours under a nitrogen purge. Further, 14 parts by weight of acetylacetone was added. Stirring was continued overnight under a nitrogen purge while purging out the by-produced hydrogen chloride gas to prepare a polymerization catalyst solution.
[0056]
Next, based on a monomer mixture consisting of 95 parts by weight of purified dicyclopentadiene (purity: 99.7% by weight, the same applies hereinafter) and 5 parts by weight of purified ethylidene norbornene (purity: 99.5% by weight, the same applies hereinafter), 70% by mole of ethylene was contained. To a solution obtained by adding 3 parts by weight of an ethylene-propylene-ethylidene norbornene copolymer rubber and 2 parts by weight of Ethanox 702 manufactured by Ethyl Corporation as an oxidation stabilizer, the above-mentioned catalyst solution for polymerization has a tungsten content of 0.01 M (mol) / L. To prepare a solution A containing a catalyst component.
[0057]
[Reference Example 2]
(Preparation of solution B)
Trioctyl aluminum 85, a solution obtained by dissolving 3 parts by weight of an ethylene-propylene-ethylidene norbornene copolymer rubber containing 70 mol% of ethylene in a monomer mixture consisting of 83 parts by weight of purified dicyclopentadiene and 5 parts by weight of purified ethylidene norbornene, A mixture of activators for polymerization prepared by mixing and preparing dioctyl aluminum iodide 15 and diglyme at a molar ratio of 100 was added at a ratio such that the aluminum content became 0.03 M / L to prepare a solution B containing an activator component. .
[0058]
[Example 1]
(Molding and in-mold coating)
An injection port for paint injection was provided in a cavity mold of a mold for molding an outboard motor cover having a length of 800 mm, a width of 600 mm, and a depth of 600 mm (made of a nickel mold of a cavity mold and an aluminum mold of a core mold). .
[0059]
The cavity mold temperature was 90 ° C., the core mold temperature was 60 ° C., and the mold was clamped at a pressure of 1.5 MPa.
[0060]
Using a RIM molding machine, equal amounts of the solution A and the solution B described in Reference Examples 1 and 2 were impact-mixed in a mixing head, and the obtained mixture was injected into a mold and held for 60 seconds.
[0061]
Subsequently, the undercoat paint was applied in a two-liquid system according to the present invention by an in-mold coating method. Liquid X and liquid Y were separately supplied to a paint injection device connected to a paint inlet attached to a mold. As the liquid X, a mixed solution of 100 parts by weight of an unsaturated polyester resin (Epolac SD4000 manufactured by Nippon Shokubai Co., Ltd.), 20 parts by weight of titanium oxide, and 45 parts by weight of talc is used. As the liquid Y, bis (4-t-butylcyclohexyl) is used. A mixture of 3.0 parts by weight of peroxycarbonate, 1.0 part by weight of cobalt octylate as an accelerator, and 40 parts by weight of a saturated polyester resin as a modifying resin was used. Both liquids were impact-mixed at a pressure of 15 MPa in an injection device at a weight ratio of 4: 1 and injected into a mold. The mixed coating liquid showed a characteristic of a gelation time of 6 seconds at 90 ° C.
[0062]
After the paint was injected, it was kept in the mold for 3 minutes, and then the mold was opened and the molded product was taken out. The coating material spread evenly over the entire circumference of the molded product, and a good product having no unpainted portions was obtained.
[0063]
Thirty minutes after removing the molded product from the mold, a paint (green color) of POINAL 800N manufactured by Ohashi Chemical Co., Ltd. was applied and baked through a dryer at 80 ° C. Table 1 shows the results of the durability test of this coating.
[0064]
[Comparative Example 1]
With respect to the coating material for in-line coating used in Example 1, Liquid X and Liquid Y were mixed at the same compounding ratio as in Example 1 to prepare a one-liquid coating material. After mixing and producing this coating material, it was kept in a room at 30 ° C. close to the molding atmosphere for one day, and was then subjected to in-mold coating on an outboard motor cover molded with the same mold as in Example 1 by a one-liquid system. The paint viscosity at the time of in-mold coating was 20% higher than immediately after mixing. The coating material injected by the one-pack system could not cover the entire surface of the molded product, and an unpainted portion was generated.
[0065]
As described above, it was confirmed that the pot life was shortened with the paint in which the liquid X and the liquid Y were mixed in advance, so that the entire area of the molded product could not be painted.
[0066]
[Comparative Example 2]
Using the mold of the outboard motor cover of Example 1, a crosslinked polymer was molded from the solution A and the solution B in the same manner as in Example 1, and was taken out as it was without performing in-mold coating. Thirty minutes after the removal, a polynal primer manufactured by Ohashi Chemical Co., Ltd. was applied, and after drying, 800 N of polynal was applied and baked through a dryer at 80 ° C. Table 1 shows the results of the durability test of this coating.
[0067]
[Comparative Example 3]
A molded product without in-mold coating was used in the same manner as in Comparative Example 2, and after taking out from the mold, the surface was immediately sanded with # 320 sandpaper. 800N was applied and baked. Table 1 shows the results of the durability test of this coating.
[0068]
[Table 1]

[0069]
From these results, in the present invention, labor-intensive work steps such as primer treatment and sanding can be omitted, and if applied to the application of an undercoat paint, it can be applied immediately after molding, and the type of paint used is diversified. It is understood that the range of control conditions for in-mold coating can be expanded while taking advantage of the features of the in-mold coating method that can be performed, and thereby uniform coating can be stably performed.
[0070]
【The invention's effect】
According to the present invention, there is provided an in-mold coating technique capable of stably applying a uniform coating to a molded product made of a norbornene-based crosslinked polymer.

Claims (3)

A mixture containing a norbornene-based monomer is injected into a mold composed of a cavity mold and a core mold, crosslinked and polymerized to form a molded article, and the molded article is coated by an in-mold coating method to produce a painted molded article. A method for producing a coated molded product, comprising: mixing and injecting into a mold a two-pack type paint of a liquid X containing a colorant and a vehicle component as main components and a liquid Y containing a curing agent as a main component. The coating molding according to claim 1, wherein the liquid X and the liquid Y are supplied through separate lines, mixed by collision in a paint injection device attached to the mold, and injected into the mold at a pressure of 7 to 34 MPa. Method of manufacturing a product. As the vehicle component, an unsaturated polyester resin, an epoxy acrylate oligomer, a polyester acrylate oligomer and at least one of a group consisting of urethane acrylate oligomer and an ethylenically unsaturated monomer copolymerizable therewith,
3. The method for producing a coated molded product according to claim 1, wherein the curing agent contains a polymerization initiator and, in some cases, an accelerator for the polymerization initiator.