JPH09141718A - Production of reactive resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a reactive resin sheet capable of forming a coating layer high in hardness without using an org. solvent and deteriorating work environment by an inexpensive and simple process. SOLUTION: A vinyl monomer containing at least a (meth) acrylic monomer having at least one group among a hydroxyl group, an amide group and a carboxyl group, block isocyanate and a radical polymerization initiator are changed in a single or twin-screw extruder capable of continuously transferring content while renewing the surface thereof and having a temp. control mechanism in its transfer process. After the monomer is polymerized in the extruder, the obtained polymer is shaped into a sheet by the sheet mold provided to the extruder so that the concn. of the unreacted monomer component is set to 10000ppm or less.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a reactive resin sheet for forming a coating layer on the surface of an article, and more specifically, it is constituted by using a thermosetting reactive resin composition, The present invention relates to a method for producing a reactive resin sheet which forms a cured film by heat curing after being coated on the surface of an article.

[0002]

2. Description of the Related Art A paint is generally used to form a coating layer for the purpose of anticorrosion on the surface of various articles such as furniture, plastic moldings or steel plates, or to give decoration or various indications. ing. However, when the surface of an article is coated with a solvent-based paint, there are problems that it takes a long time to dry the paint and the working environment is deteriorated due to volatilization of the organic solvent during work. Therefore, in order to solve these problems, a method of using a sheet-shaped coating material instead of the paint has been proposed.

For example, when a coating layer or the like is formed on the surface of an article by using a sheet-shaped coating material mainly composed of polyvinyl chloride, the above-mentioned problems such as deterioration of working environment hardly occur and the sheet-shaped coating material is used. Therefore, it is not necessary to dry after attaching, and the work can be simplified. However, since the sheet-shaped coating material is mainly formed of soft polyvinyl chloride, the formed coating layer has a hardness,
There is a defect that the impact resistance and the abrasion resistance are not sufficient and that cracks are easily generated.

Therefore, for example, Japanese Patent Laid-Open No. 1-294723.
Japanese Patent Publication proposes a specific thermosetting reactive resin sheet obtained by polymerizing an acrylic monomer, and a coating layer obtained by curing the reactive resin sheet has a high hardness. Is listed.

[0005]

However, in producing the above-mentioned reactive resin sheet, a polymer solution is prepared by using an organic solvent, and the polymer solution is applied onto a substrate film, followed by drying, and thereafter. A method of peeling a thin reactive resin sheet from a base film is used. That is, in order to obtain a reactive resin sheet, it is necessary to use an organic solvent such as ethyl acetate or toluene, and it was essential to carry out a step of mixing these solvents with an acrylic polymer or various additives. . Furthermore, a drying step for volatilizing the solvent is also required. Further, in order to polymerize the acrylic polymer, an organic solvent is required, and further, in order to form a coating layer having a desired hardness,
In order to manufacture the reactive resin sheet, the polymerization conditions of the acrylic polymer had to be controlled with high precision, and a very complicated process had to be carried out.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to form a coating layer having high hardness without using an organic solvent and without deteriorating the working environment. It is an object of the present invention to provide a method capable of manufacturing a sheet at a low cost by a simple process.

[0007]

Means for Solving the Problems The inventors of the present invention have made earnest studies to achieve the above-mentioned object, and as a result, specified vinyl monomer composition, blocked isocyanate and radical initiator were identified as unreacted monomer component concentrations. The present invention has been completed by finding out what can be achieved by polymerizing in an extruder so that the concentration becomes equal to or lower than, and shaping into a sheet shape when extruding from the extruder.

That is, the method for producing a reactive resin sheet of the present invention comprises a vinyl monomer containing at least a (meth) acrylic monomer having at least one of a hydroxyl group, an amide group and a carboxyl group, a blocked isocyanate, and a radical. The polymerization initiator and the content can be continuously transferred while renewing the contents, and charged into a single-screw or twin-screw extruder equipped with a temperature control mechanism in the transfer process, and the monomer is charged in the extruder. After the polymerization, a method for producing a reactive resin sheet is characterized in that the unreacted monomer component concentration is adjusted to 10,000 ppm or less and the sheet is shaped into a sheet by a sheet mold equipped in an extruder. .

Hereinafter, the present invention will be described in detail. Materials Used in the Present Invention In the present invention, a vinyl-based monomer containing at least a (meth) acrylic monomer having at least one of a hydroxyl group, an amide group and a carboxyl group, and a blocked isocyanate are uniaxially combined with a radical polymerization initiator. Alternatively, it is charged into a twin-screw extruder in various forms described below, and a reactive resin sheet containing an acrylic polyol obtained by radical polymerization of the vinyl-based monomer and a blocked isocyanate as a main component is manufactured. The acrylic polyol contained in this resin sheet is an acrylic polymer having a plurality of hydroxyl groups and is a solid or solid solution at room temperature.

In the present invention, the acrylic polyol is formed in the extruder. When the acrylic polyol is taken out from the extruder by itself, the weight average molecular weight thereof is 100,000 or more and 2,000,000 or less. preferable. When the weight average molecular weight is less than 100,000, it is difficult to retain the shape of the obtained reactive resin sheet, or sufficient elongation cannot be obtained during stretching during sticking work. May crack. On the other hand, when the weight average molecular weight is more than 2,000,000, extrusion becomes difficult and the smoothness of the resulting reactive resin sheet is greatly impaired. The glass transition temperature (Tg) of the acrylic polyol has a Tg of 20 to 20 when a particularly high hardness is required in view of the hardness after curing.
Those in the range of 80 ° C. are preferred.

The above-mentioned acrylic polyol comprises, for example, a (meth) acrylic acid ester monomer, a styrene derivative polymer, and a (meth) acrylic acid ester monomer having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, which is uniaxially or biaxially. It can be obtained by copolymerization in a shaft extruder.

Specific examples of the (meth) acrylic monomer having at least one of the above hydroxyl group, amide group and carboxyl group used in the present invention include methyl methacrylate, ethyl methacrylate and propyl methacrylate. , Butyl methacrylate, octyl methacrylate, stearyl methacrylate, glycidyl methacrylate, acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, -2 ethylhexyl acrylate, methacrylic acid, and N-methyl (meth) acrylamide, N-vinylacetamide, N, N-diethyl (meth) acrylamide, (meth) acrylonitrile, hydroxy (meth) acrylate and the like are preferable.

Further, in the present invention, a vinyl-based monomer containing the above-mentioned (meth) acrylic-based monomer is used, that is, a vinyl-based monomer other than the (meth) acrylic-based monomer having one of the above-mentioned hydroxyl group, amide group or carboxyl group. Examples of the monomer include alkylstyrene such as o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, ethylstyrene, dimethylstyrene and butylstyrene, styrene derivative such as chlorostyrene, vinyl acetate and N-vinyl. Pyrrolidone, maleic anhydride and the like are preferred.

Further, as the polymerization initiator for obtaining the above-mentioned acrylic polyol, a general radical polymerization initiator used for ordinary solution polymerization of an acrylic polymer can be used. However, preferably, it is soluble in vinyl monomers including (meth) acrylic monomers,
It is desirable that the half-life temperature of time is in the range of 60 to 200 ° C. If an initiator having a one-hour half-life temperature of less than 60 ° C. is used, the polymerization reaction may be too fast, and a runaway reaction may occur. On the other hand, if a half-life temperature of more than 200 ° C. is used, the polymerization reaction rate becomes too slow, and it becomes difficult to complete the polymerization reaction in the extruder. Further, if the temperature of the reaction system is raised to complete the polymerization reaction, problems such as volatilization and decomposition of the monomer or decomposition of the polymer are likely to occur.

The half-life temperature of 1 hour means a temperature at which the half-life of a substance dissolved in benzene or toluene shows 1 hour. The half-life of the above-mentioned polymerization initiator is, for example, diphenyl-1-, which is one of the polymerization inhibitors.
It can be determined by using picrylhydrazyl and measuring its disappearance rate by an ultraviolet absorption spectrum.

Specific examples of the above-mentioned polymerization initiator that can be used in the present invention include, for example, benzoyl peroxide,
Diacyl peroxides such as 2,4-dichlorobenzoyl peroxide, p-chlorobenzoyl peroxide, o-methylbenzoyl peroxide and bis-3,5,5-trimethylhexanol peroxide; dicumyl peroxide, 2,5- Dimethyl-2,5- (t
-Butylperoxy) -hexane, t-butylcumyl peroxide, di-t-butylperoxide, 1,3
-Bis- (t-butylperoxyisopropyl) -benzene and other dialkyl peroxides; 1,1-di-t-
Peroxyketals such as butylperoxycyclohexane; alkylperesters such as t-butylperoxybenzoate; organic peroxides such as percarbonates such as diisopropylperoxycarbonate; 2,2'-azobis (2,4-dimethylvalero) Nitrile), 2,2 '
Examples thereof include azonitrile compounds such as azobisisobutyronitrile and 2,2′-azobiscyclohexylnitrile.

The addition amount of the above-mentioned polymerization initiator is the above-mentioned (meth).
Total amount of vinyl monomers including acrylic monomers 10
The amount is preferably 0.02 to 2 parts by weight with respect to 0 parts by weight. If the amount of the polymerization initiator added is less than 0.02 parts by weight, it may be difficult to complete the reaction in the extruder. If it exceeds 2 parts by weight, the polymerization reaction rate becomes too fast, resulting in a runaway reaction. The risk increases.

The blocked isocyanate used in the present invention is used as a heat-reactive type curing agent for curing the acrylic polyol when the reactive resin sheet is used and then thermally cured when used.

In the present specification, blocked isocyanate means that the isocyanate group of an isocyanate compound having two or more isocyanate groups in the molecule is blocked with a blocking agent such as phenol, oxime, ε-caprolactam or malonic acid ester. It means a compound. Here, examples of the above-mentioned isocyanate compound include monomers such as tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, or trimethylolpropane adducts thereof, isocyanurate modified products, and carbodiimide modified products. be able to.

In the above-mentioned blocked isocyanate, the blocking agent is desorbed by heating, and the resulting isocyanate group cross-links with the hydroxyl group of the acrylic polyol. The content of the blocked isocyanate is, for example, in the case of acrylic polyol, the ratio (OH value / NCO value) of the number of hydroxyl groups contained in the acrylic polyol to the number of isocyanate groups contained in the blocked isocyanate is 0.5 to It is preferably selected to be in the range of 2.0, and more preferably in the range of 0.8 to 1.2. If the ratio of the number of hydroxyl groups to the number of isocyanate groups is less than 0.5, the cured film strength at the time of heat curing may not be a sufficient strength that is desired, and if it exceeds 2.0, the strength may not be sufficient. The isocyanate groups in the reaction may remain, and the physical properties such as weather resistance of the coating film may be deteriorated.

In the present invention, other colorants such as pigments and dyes may be added to the extruder as needed, as long as the object of the present invention is not impaired. As the colorant, pigments and dyes used in ordinary paints can be appropriately used. For example, pigments include titanium oxide, iron oxide, carbon black, cyanine pigments, quinacridone pigments, etc., and dyes include azo dyes, anthraquinone dyes, indigoid dyes, stilbene dyes, etc. In addition, aluminum flakes, metal powder such as nickel powder, gold powder, and silver powder may be used as the coloring agent.

When a colorant having a high hiding power is used, the total amount of the colorant is preferably in the range of 2 to 100 parts with respect to 100 parts by weight of the solid content of the resin. When the amount is less than 2 parts by weight, the desired hiding property cannot be realized, and when the amount is more than 100 parts by weight, it may be difficult to uniformly disperse the colorant on the sheet. .

Further, if necessary, a filler such as glass fiber, mica, talc, an antiaging agent, an ultraviolet absorber or the like may be used. In addition, the ultraviolet absorber,
Since some act as a polymerization inhibitor, when the ultraviolet absorbent is contained in the reactive resin sheet, it is necessary to take a method of supplying the composition to the extruder or compounding it after the acrylic monomer is sufficiently polymerized. is there.

Manufacturing Process In the present invention, the above materials are charged into a single-screw or twin-screw extruder, and after the monomers are polymerized in the extruder, the unreacted monomer component concentration is 10,000 pp as described above.
A thermosetting resin composition containing an acrylic polyol and a blocked isocyanate is shaped into a sheet by a sheet mold provided in an extruder so as to have a thickness of m or less.

The concentration of the unreacted monomer component contained in the above-mentioned reactive resin sheet is 10,000 ppm or less,
If it exceeds 10000 ppm, not only the odor becomes extremely strong during sheet formation, but also when the sheet is attached to an adherend after sheet formation and cured by heating, the reactive resin sheet foams to form a uniform film. Because it will not be possible. The residual monomer component concentration is preferably 1000 ppm or less, more preferably 50 ppm or less.
It is 0 ppm or less.

By the way, the residual monomer component concentration is set to 1
In order to reduce the amount to 0000 ppm or less, it is preferable that the extruder is equipped with a device for recovering the residual monomer.
This recovery device is not particularly limited, but, for example, a structure in which one or more vent ports for vacuum degassing are provided in the extruder barrel and vacuum suction is performed from the vent port is preferably used. To be In this case, the vacuum type vent device that can be used is usually composed of a vent port, a vacuum pump, a drain trap and a hose connecting them, and a vacuum gauge is provided near the vent port. , It is also possible to know the vacuum degree of the system.

The vacuum degree of the system suitable for the production method of the present invention is
200 mmHg or less, more preferably 100 m
mHg or less. If the degree of vacuum is higher than 200 mmHg, the recovery of the residual monomer component tends to be insufficient.

The residual monomer component concentration can be measured by, for example, cutting the obtained reactive resin sheet into fine pieces,
It can be performed by immersing in an organic solvent such as tetrahydrofuran, incubating for half a day, and quantifying the monomer component eluted in the organic solvent by gas chromatography.

Various methods can be adopted for the position where each component of the above composition is charged into the extruder, but it is preferable to use one of the following three methods (a) to (c). .

In the method (a), the above components are simultaneously added to
It is a method of charging from the hopper part or its vicinity. In this case, the extruder is preferably equipped with some cooling equipment such as a screw cooling equipment.
If the cooling system is not provided, the temperature of the reaction system may rise excessively, causing a runaway reaction, or the blocked isocyanate may decompose.

In the method (b), the blocked isocyanate is dissolved in advance in one of the vinyl monomers including the (meth) acrylic monomer, and this solution is simultaneously added to the extruder as in the method (a). It is a method of throwing in. Even in this case, for the same reason as in the case of the method (a),
The extruder is preferably equipped with cooling equipment.

In the method (c), first, several kinds of (meta)
A vinyl monomer including an acrylic monomer and a polymerization initiator are charged from a hopper of an extruder or a charging port provided near the hopper. Next, a blocked isocyanate and other additives typified by pigments are charged through a charging port provided in an extruder designed in consideration of a position where the polymerization reaction has progressed to some extent. In the method of (c),
It is preferable to introduce each component into the extruder in the above-described procedure, whereby the following problems can be avoided. That is, the blocked isocyanate is activated in the extruder, and a partial crosslinking reaction with the acrylic polyol causes an extremely high viscosity, making it impossible to extrude, or a reactive resin sheet with low uniformity. The inconvenience of becoming less likely to occur. However, since there is a risk that the temperature of the reaction system rises too much and a runaway reaction occurs, it is preferable that the extruder be equipped with some cooling equipment such as a screw cooling equipment.

In any of the above methods, the specific method of charging each component into the extruder is arbitrary, but preferably a quantitative charging device, a press-fitting device, for example, In the case of a liquid, it is desirable to feed it through a metering pump, and in the case of a solid, it is fed through a feeder. This is because when the charging method or charging device lacks quantitativeness, the obtained resin sheet may become non-uniform, and it is preferable to suppress the entrainment of air into the extruder.

The barrel temperature of the above-mentioned single-screw or twin-screw extruder is appropriately set, but the temperature profile in a plurality of barrels and each barrel is determined by the type of (meth) acrylic monomer and polymerization initiator used, and the average retention. It depends on the time. However, essentially, in the former part of the extruder, the vinyl monomer component including the (meth) acrylic monomer is transferred while raising the temperature within the range that does not cause boiling or runaway reaction, and the polymerization reaction proceeds sufficiently in the central part. Then
It is preferable that the temperature of each stage is set so that the polymer viscosity is such that screw pumping is possible in the latter stage.

Further, in the entire system, specifically, it is necessary to control so that the resin temperature does not exceed the decomposition temperature of the blocked isocyanate (desorption temperature of the block portion).
This is because when the decomposition temperature is exceeded, the acrylic polyol and the blocked isocyanate are crosslinked in the extruder, the viscosity of the thermosetting resin composition becomes extremely high, and extrusion becomes impossible. On the other hand, since the polymerization reaction from the monomer is carried out in the extruder, it is possible to easily change the molecular weight of the resulting thermosetting resin composition by simply changing the conditions such as the temperature setting and the screw rotation speed. Therefore, the hardness of the reactive resin sheet can be easily adjusted.

The vinyl-based monomer including the (meth) acrylic-based monomer charged into the extruder has a dissolved oxygen concentration of 2 p.
It is preferably pm or less. If the dissolved oxygen concentration exceeds 2 ppm, the polymerization reaction will not be completed in the extruder,
This is because problems such as generation of oligomers may occur. Specifically, it is preferable to employ a technique such as degassing or replacement with an inert gas. The dissolved oxygen concentration can be directly measured by, for example, a polarographic dissolved oxygen meter using platinum / silver as an electrode.

The single-screw extruder used in the present invention includes:
In addition to those with general full flight type screws,
A screw having a discontinuous flight type screw, a pin barrel, a mixing head, or the like can be used. As the twin-screw extruder, any of a meshing same-direction rotating type, a meshing different-direction rotating type, and a non-meshing different-direction rotating type may be used.

It is preferable to use an intermeshing (self-wiping) co-rotating twin-screw extruder partially having a kneading disc element. Whichever screw extruder is selected, it is preferable that the extruder barrel is provided with one or more vent ports for vacuum degassing. This is because the monomer component of the reaction can be easily removed and it can be effectively used in reducing oxygen in the extruder.

In the production method of the present invention, two or more thermosetting resin compositions are produced in the above-described manner by individual uniaxial or biaxial extruders, and a plurality of extruded resin compositions are obtained. A method (that is, a co-extrusion method) in which the resin sheets having a multi-layered structure are obtained by joining them into one can be adopted. The merging by co-extrusion can be performed in a feed block or a sheet mold provided in the extruder.

In the method using a feed block, a special block attached immediately before entering a die (die) is used for joining, and is also called a black box method. The latter method, that is, the method of merging in the sheet mold includes a multi-manifold method, a multi-throttle die method, and the like. In the multi-manifold method, as many manifolds as the number of layers are provided in the die. In the multi-throttle die method, separate streams flow in the die, and the layers are bonded immediately after leaving the die. Even when any of the above joining methods is adopted, the laminated body of the reactive resin sheet of the present invention can be manufactured. However, in order to improve the thickness accuracy of each layer and the adhesiveness between the layers, it is preferable to adopt the multi-manifold method, among others. Further, different coextrusion methods such as the feed block method and the multi-manifold method may be used in combination.

Application The reactive resin sheet obtained by the present invention can be used in place of conventional coating of various articles, and is a transparent sheet or a colored sheet of each color depending on the presence or type of the colorant contained. Can be configured as. Further, by adopting the above-mentioned co-extrusion method, for example, a reactive resin sheet having a two-layer structure such as a transparent layer / colored layer can be formed, and thereby a coating layer having various structures can be formed.

The reactive resin sheet obtained by the present invention is in an uncured state before heating and is excellent in malleability and flexibility. Therefore, it is excellent along the surface of an article having irregularities or curved surfaces. It is possible to form a different coating layer.

Further, a hard coating can be formed by coating the surface of the article with the reactive resin sheet and then heating the article at a temperature higher than a predetermined temperature. Incidentally, when the reactive resin sheet does not have a sufficient adhesive force to the article to be coated, an adhesive layer may be further laminated on the surface, and the article surface may be attached via the adhesive layer. A reactive resin sheet may be attached. Lamination of the adhesive layer may be carried out by adopting a coextrusion method at the time of producing the reactive resin sheet, or after obtaining the reactive resin sheet by the method for producing a reactive resin sheet according to the present invention. Alternatively, the adhesive layer may be laminated by secondary processing.

Examples of the adhesive layer include vinyl acetate emulsion hot melt adhesives, styrene-isoprene-styrene (SIS) hot melt adhesives, acrylic hot melt adhesives, unsaturated polyester uncrosslinked materials, Examples thereof include acrylic pressure-sensitive adhesives and post-cured acrylic adhesives, and blended products or laminates thereof may be used as the adhesive layer.

Action In the present invention, the above-mentioned components are fed into the single-screw or twin-screw extruder for polymerization and kneading, and the reactive resin sheet having a residual monomer component concentration of 10,000 ppm or less is extruded from the extruder. Therefore, in the process of polymerizing the acrylic polyol and the process of kneading with the blocked isocyanate and other additives, the reactive resin having the desired characteristics can be obtained by selecting a specific temperature range and conditions for charging the raw materials into the extruder. The sheet can be easily obtained. That is, it is possible to avoid problems such as decomposition of the blocked isocyanate in the extruder during polymerization and kneading, an inconvenience caused by an extreme increase in viscosity, and conversely, an inconvenience caused by residual monomer components due to insufficient polymerization.

Furthermore, it becomes possible to uniformly and quickly knead the blocked isocyanate and the pigment into the acrylic polyol.

[0047]

Embodiments of the present invention will be described below in detail. In the following, "part" means "part by weight"
Shall mean.

Example 1 A self-wiping type double-threaded screw element and a kneading disc element, having a diameter of 39 m.
Width 500 mm at the tip of a meshing type co-rotating twin-screw extruder (Plastic Engineering Laboratory Co., Ltd., trade name: BT-40) equipped with a screw of m, L / D ratio = 42,
A sheet-shaped T-die having a slit width of 350 μm was attached. The preset temperature is 60 ° C. at the inlet (first to second barrel section), 100 ° C. at the center (third to sixth barrel section),
The outlet (the seventh barrel and the die section) was heated to 110 ° C., the screw rotation speed was set to 50 rotations / minute, and the barrel cooling device provided in the extruder was driven.

Methyl methacrylate (hereinafter abbreviated as MMA), butyl methacrylate (hereinafter abbreviated as BMA) and 2-hydroxyethyl methacrylate (hereinafter 2-H)
(Abbreviated as EMA), each weighing 80 kg in a tank having a capacity of 100 liters, nitrogen gas (purity 99.9%) is blown at a flow rate of 5 liters / minute while keeping the temperature at 25 ° C. or lower, and nitrogen of dissolved oxygen is discharged. Substitution was made. At this time,
The oxygen concentration of the solution in the tank was measured by a dissolved oxygen meter (Central Chemical Co., trade name: UC-12-SOL),
Nitrogen substitution was stopped when the oxygen concentration reached 0.1 ppm.

By the chemical gear pump, MMA35
Part, BMA 35 parts and 2-HEMA 30 parts and 2,2-azobisisobutyronitrile as a polymerization initiator (hereinafter,
0.1 part (abbreviated as AIBN) was individually supplied from a charging port provided near the hopper of the extruder to perform bulk polymerization. The total supply rate of the above-mentioned three kinds of monomers is 50 g.
/ Min. Further, the pressure was reduced from two vent ports provided in the seventh barrel near the exit of the extruder to deaerate volatile components.

From a charging port provided in the vicinity of the fifth barrel, a blocked isocyanate (manufactured by Takeda Pharmaceutical Co., Ltd., trade name: Takenate B-815N, oxime block of hydrogenated diphenylmethane diisocyanate, NCO content of 7.3% by weight,
Decomposition temperature = 140 ° C. to 150 ° C.) in a ratio of 76 parts (this is a ratio having 1.0 equivalent of isocyanate groups with respect to hydroxyl groups of the acrylic polyol after the monomer polymerization) with respect to 100 parts of the total amount of the above three kinds of monomers. Was supplied.

A part of the resin sheet discharged from the evaluation die and made of the thermosetting resin composition composed of the above components was sampled to obtain an evaluation sample.

The appearance of the sample was visually judged. Also,
The thickness was measured at arbitrary 10 points of the sample, and the average value was used as the sheet thickness. Furthermore, the sample is 20 × 100m
A m-thick strip-shaped test piece was subjected to a tensile test in the longitudinal direction at 80 ° C.

Further, 20 is formed on the convex surface of a steel plate (radius of curvature 50 cm, bottom diameter 30 cm) curved like a convex lens.
A × 20 cm sample was vacuum-pressed at 80 ° C. Then, the steel plate to which the sample was attached was heated at 160 ° C. for 30 minutes to be cured, and the pencil hardness was measured.

On the other hand, in the above example, the sheet obtained by extruding without supplying the blocked isocyanate was cut into small pieces, immersed in THF and incubated for half a day, and the monomer eluted in the organic solvent was used. The components were quantified by gas chromatography.

The evaluation results are summarized in Table 1. Meanings of monomer abbreviations and raw material charging methods in Table 1 and Tables 2 and 3 described later are as follows. Monomer abbreviation; MMA (methyl methacrylate), BM
A (butyl methacrylate) 2-HEMA (2-hydroxyethyl methacrylate), HPMA (hydroxypropyl methacrylate), HMA (hydroxyl methacrylate), iP
MA (isopropyl methacrylate), i-BMA (isobutyl methacrylate), 2-EHA (2-hydroxyethyl acrylate), N-VAA (N-vinyl acetamide)

Raw material charging method: 1: After supplying each monomer component individually, supply the components other than the monomer component from another supply port. 2: (MMA + blocked isocyanate) + BMA + A
IBN. That is, the blocked isocyanate is previously added to MM.
After dissolving in A, this solution, BMA and AIBN are separately fed from the same input port. 3: Blocked isocyanate, MMA, BMA and AI
Each BN is supplied separately, but from the same input port.

Example 2 A sample was obtained in the same manner as in Example 1 except that 10 parts of the green pigment was charged together with the blocked isocyanate from the charging port for supplying the blocked isocyanate. It evaluated similarly to.

Example 3 Two twin-screw extruders shown in Example 1 were prepared and connected through a die of the multi-manifold method, and coextrusion was performed. However, the lip portion of the die was 500 mm × 0.5 mm.
One extruder was extruded under the same conditions as in Example 1, and the other extruder was extruded under the same conditions as in Example 2. Using the obtained two-layer resin sheet, evaluation was performed in the same manner as in Example 1.

Example 4 In Example 1, the extruder set barrel temperature was 60 ° C. at the inlet (first to second barrel sections), 90 ° C. at the center (third to sixth barrel sections), and the outlet. (7th barrel and die section) 100 ℃, screw rotation speed 30 rotations /
Set to minutes. Further, the blocked isocyanate is previously dissolved in MMA, which is one of the three monomer components for forming the acrylic polyol, and BMA and 2-HE are added.
The three types of MA and AIBN were separately supplied from the input ports provided near the hopper of the extruder, and bulk polymerization was performed. Except that the above conditions and the supply rate of each monomer and blocked isocyanate, that is, the total flow rate was 30 g / min, extrusion was performed in the same manner as in Example 1 to obtain a sample of the thermosetting resin sheet. Evaluation was made in the same manner as 1.

Example 5 In Example 1, the extruder barrel temperature was set at 60 ° C. at the inlet (first and second barrel sections), 90 ° C. at the center (third to sixth barrel sections), and outlet. (Seventh barrel and die section) at 100 ° C, screw rotation speed 20 rotations /
Set to minutes. Block isocyanate, MMA, BMA, and 2-HEMA, and AIBN were separately supplied from the charging ports provided near the hopper of the extruder to carry out bulk polymerization. Extrusion was performed in the same manner as in Example 1 except that the above conditions and the supply rate of each monomer, that is, the total flow rate was set to 20 g / min, to obtain a thermosetting resin sheet sample. And evaluated.

Examples 6 to 13 Monomer composition, total feed monomer flow rate, blending ratio, type of polymerization initiator, extrusion conditions, raw material charging method, etc. are as shown in Tables 2 to 3, and the thermosetting resins are respectively prepared. A sheet sample was obtained and evaluated in the same manner as in Example 1.

Comparative Examples 1 to 3 Monomer composition, total feed monomer flow rate, blending ratio, type of polymerization initiator, extrusion conditions, raw material charging method, etc. are as shown in Tables 2 and 3, and each is a thermosetting resin. A sheet sample was obtained and evaluated in the same manner as in Example 1.

[0064]

[Table 1]

[0065]

[Table 2]

[0066]

[Table 3]

In Tables 1 to 3, 80 ° C. 1
The meanings of the evaluation symbols for 00% stretching, 80 ° C. vacuum compression bonding and hardness of the cured coating are as follows. 80 ° C. 100% stretching test result ◯: When the stretching is good. ×: Broken during stretching.

Results of 80 ° C. vacuum compression test ◯: When the sample is sufficiently adhered to the convex surface. ×: When the sample does not adhere sufficiently to the convex surface.

Curing, hardness of coating ∘: No breaks or wrinkles occur on the sheet during curing. Hardness is measured by pencil hardness.

In Comparative Example 3, the sheet could not be formed. This is because in Comparative Example 3, during extrusion,
It is considered that the set temperature was as low as 60 ° C. even at the outlet, and the polymerization reaction was not completed sufficiently.

In Comparative Example 1, vacuum suction was not carried out from the degassing vent section, and the amount of residual monomer was high.
Probably, a strong irritating odor was generated at the time of sheet extrusion, and the residual monomer component concentration was as high as 20000 ppm, so wrinkles were generated in the 80 ° C. vacuum pressure bonding test, and large wrinkles were also generated in the cured film.

In Comparative Example 2, since the dissolved oxygen of the monomer was not sufficiently removed, the polymerization reaction in the extruder was nonuniform and difficult to proceed, and a sheet having a uniform thickness could not be obtained.

On the other hand, in Examples 1 to 13, Table 1
As is clear from ~ 3, by changing the blending of the raw materials, the extrusion conditions, and other conditions, it is possible to reasonably stretch under the conditions of 80 ° C and 100%, and also in the 80 ° C vacuum pressure bonding test. It can be seen that it is possible to surely form a coating film which is deposited on the surface of the article and has high hardness.

[0074]

According to the present invention, since the thermosetting resin sheet is manufactured by using the extruder, the production cost can be greatly reduced as compared with the conventional manufacturing method by the casting method. Also, since no organic solvent is used,
Environmental deterioration is unlikely to occur. Furthermore, the polymerization time of acrylic polyol and the kneading time of additives such as blocked isocyanate or pigment can be greatly shortened, and the molecular weight of acrylic polyol can be easily and quickly changed depending on the polymerization conditions in an extruder. It is possible to provide the thermosetting resin sheet for forming the coating layer, which can easily adjust the physical properties of the functional resin sheet and can exhibit desired physical properties.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area // B29L 9:00

Claims (1)

[Claims] 1. A content of a vinyl-based monomer containing at least a (meth) acrylic-based monomer having at least one of a hydroxyl group, an amide group and a carboxyl group, a blocked isocyanate, and a radical polymerization initiator is renewed on the surface. While continuously transferable, and charged into a single-screw or twin-screw extruder equipped with a temperature control mechanism in the transfer process, after polymerizing the monomer in the extruder, the unreacted monomer component concentration A method for producing a reactive resin sheet, which comprises shaping the sheet into a sheet shape by a sheet mold provided in an extruder so that the content becomes 10000 ppm or less.