JPH0375010B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for manufacturing molded products such as bathtubs, washstands, system kitchen worktops, tiles, etc., which are required to have both aesthetic appearance and water resistance. [Conventional technology] Taking a bathtub as an example, the traditional method was to apply a colored gel coat and then line it with polyester resin and glass fiber to produce a single-colored, non-transparent bathtub. It was done in a different way. However, as the required appearance and performance have become more sophisticated, the manufacturing method has also changed. For example, transparent marble-like bathtubs are manufactured by applying a transparent gel coat, then lining and laminating with glass fiber and resin, and then casting with resin mixed with filler. There is a trend. In some cases, gel coating is followed by casting without using glass fiber, which is spurring product diversification. The problem is that such molded products have insufficient hardness and boiling resistance at the level of conventionally used gel coats. That is, when hydrated alumina is used as a filler for a casting resin, the casting layer becomes white due to the action of hot water passing through the gel coat layer, which significantly impairs the appearance. Although vitreous fine powder fillers tend to be less prone to such whitening phenomenon, they often cause blisters in the gel coat layer, which has the disadvantage of completely detracting from the commercial value. [Problems to be Solved by the Invention] Other than the above-mentioned drawbacks, the present invention can be fully satisfied even in a single-sided boiling test, which is considered to be the most severe test, that is, a continuous boiling test in which only the gel coated surface is brought into contact with boiling water. The present invention relates to a method for manufacturing a molded article exhibiting physical properties. [Means for Solving the Problems] That is, the present invention applies a gel coat to a mold, and performs lining molding on the mold using a filler-containing resin to obtain a molded product. (b) A woven or nonwoven fabric made of fibers is impregnated with an unsaturated urethane resin side chain unsaturated polymer containing at least two unsaturated urethane structures having at least two terminal unsaturated groups via urethane bonds, or The object of the present invention is to provide a method for producing a molded article exhibiting excellent physical properties that eliminates the above-mentioned drawbacks by setting the coated layer as an intermediate layer. [Function] To aid in understanding the present invention, a cross section of a molded article according to the present invention is shown in FIG. The next layer of the gel coat is a filler-containing resin (resin) that is provided as an intermediate layer (surface reinforcing layer) by impregnating and coating a woven or nonwoven fabric made of glass fiber with radical-curable polyester resin or vinyl ester resin. Concrete) molded bodies and methods for producing the same have already been proposed. The main purpose of the conventional method is to eliminate the disadvantages of filler-containing resin (resin concrete (abbreviated as resin concrete)), which alone has large shrinkage during curing and low tensile strength and bending strength. The object of the present invention is to provide a relatively light-weight plastic molded product with good dimensional accuracy by reinforcing one or both sides with fiber reinforced plastic (FRP). However, since the next layer after the gel coat, that is, the intermediate layer (surface reinforcing layer), is a woven or nonwoven fabric made of glass fiber impregnated and coated with radical curing polyester resin or vinyl ester resin,
Water resistance and hot water resistance (boiling resistance) are insufficient,
After about 300 to 400 hours, yellowing and blistering of the glass fibers in the gel coat layer and whitening of the casting layer occurred, significantly deteriorating the appearance. In the present invention, an unsaturated urethane resin containing at least two special unsaturated urethane structures is used as the resin impregnated and applied to a woven or nonwoven fabric made of glass fibers, so it has excellent hydrolysis resistance. Therefore, if the gel coat layer has a certain degree of water resistance, the obtained molded product will have significantly improved boiling resistance, will not yellow or whiten, and will have a good color tone after a boiling test.
It is thought that transparency will also be improved. The woven fabric or nonwoven fabric made of glass fiber used in the present invention includes:
There are glass fiber cloths, chopped strands, glass mats, surfacing mats, etc., and their density is not particularly limited, but is 150 g/m ²
The above are preferred, and those that have been treated with borane or silane are preferred. The unsaturated urethane resin used in the present invention is a curable resin containing at least two unsaturated urethane structures having at least two terminal unsaturated groups via urethane bonds, and is represented by the following general formula []. shown. [．． However, R represents a substituent having a terminal unsaturated group via an ether bond or an ester bond, G represents a polyvalent isocyanate residue, A represents a polyhydric alcohol residue, n is 2 to 3, and m is 1 to 2, l is an integer of 1 or 0]. Such an unsaturated urethane resin has the following properties: (1) an unsaturated alcohol having one hydroxyl group and two unsaturated groups in one molecule and a polyhydric isocyanate, in which the isocyanate group and the hydroxyl group are substantially (2) producing an isocyanate adduct by reacting 1 mole of a polyhydric alcohol with a polyhydric isocyanate so that the amount is substantially 2 moles, and then It can be produced by reacting it with 2 moles of the unsaturated alcohol. As a representative example of the unsaturated urethane resin of the present invention obtained by the first method, for example, one of the unsaturated urethane resins obtained by adding diisocyanate to the reaction product of glycidyl methacrylate and methacrylic acid. Give an example. Furthermore, representative examples of unsaturated urethane resins obtained by the second method will be listed. Polyhydric alcohol (A) having two or more hydroxyl groups in one molecule Vinyl ester resin (B) that shares two or more (meth)acryloyl groups and hydroxyl groups in each molecule (iv) (B)+Isocyanate adduct (C)→ An example of the curable resin structure of the present invention is shown. The most preferred unsaturated alcohol having one hydroxyl group and two unsaturated groups in the molecule that can be used in the present invention is a reaction product of glycidyl methacrylate and (meth)acrylic acid. Examples include glycerin di(meth)acrylate. Similar compounds include trimethylolpropane di(meth)acrylate and trimethylolethane di(meth)acrylate. However, these do not have a single composition, but contain several percent of mono(meth)acrylate and tri(meth)acrylate.
It is a mixture containing acrylate. Furthermore, there is glycerin allyl ether (meth)acrylate obtained by reacting allyl glycidyl ether with (meth)acrylic acid. Further, a compound obtained by reacting an epoxy resin having two or more epoxy groups in one molecule with (meth)acrylic acid, each of which shares two or more (meth)acryloyl groups and hydroxyl groups in one molecule. There is a built-in ester resin. Vinyl ester resin is produced by reacting (meth)acrylic acid with an epoxy resin having two or more epoxy groups in one molecule so that the epoxy groups and carboxyl groups are substantially equimolar. Manufactured. As an example of the epoxy resin used in the production of vinyl ester resin, it is desirable to use a type that does not have many free hydroxyl groups. For example, as a diglycidyl ether type of bisphenol A, Epicote 827 of Yuka Shell Co., Ltd.
828, 834, 1001, Dow DER-330, 331,
332, GY-257 from Ciba, Epicron #840, 850, 810 from Dainippon Ink Chemical Co., Epotote VD-115, -127 from Toto Kasei, AER330 from Asahi Kasei,
Examples include 331. Typical examples of Novolac's glycidyl ether type epoxy resins include DEN-431 and DEN-438 from Dow. Although there are many types of cycloaliphatic epoxy resins in the literature, in practice only ERL-4221 from Union Carbide is commercially available, and this can also be used in the present invention. In addition, as a special epoxy resin, a biphenyl type resin called YX-4000 manufactured by Yuka Shell Co., Ltd. can also be used. A diglycidyl ether type epoxy resin using bisphenol F and bisphenol S instead of bisphenol A, such as Epicote 807 type manufactured by Yuka Shell Co., Ltd., can also be used. There is also a type in which alkylene oxide is added to bisphenol A and the terminal hydroxyl group is epoxidized with epichlorohydrin. The reaction between the epoxy resin and (meth)acrylic acid is carried out at a temperature of 100 to 140°C, using catalysts such as tertiary amines and quaternary ammonium salts, and polyhydric phenols,
It is carried out in the presence of air using a quinone stabilizer. The diisocyanates used in the present invention are not particularly limited, and include, for example, the following types. 2,4-tolylene diisocyanate, 2,4-
Mixture of tolylene diisocyanate and 2,6-tolylene diisocyanate, tolydine diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate Isocyanate, 1,5-naphthylene diisocyanate. The polyhydric alcohol used in the present invention includes:
A prepolymer having an aromatic nucleus in the molecule is preferable, and specifically, it is obtained by reacting a monoepoxy compound with a polyhydric phenol or novolak, or by reacting an epoxy resin with a phenol.
Included are prepolymers containing two or more alcoholic hydroxyl groups in the molecule and water additives thereof. Examples of the polyhydric phenols used in the present invention include the following types. Bisphenol A, bisphenol F, bisphenol S, catechol, resorcinol, hydroquinone. Phenols used in so-called novolacs obtained by reacting phenol and formaldehyde with an acid catalyst include phenol, o-cresol, m-cresol, p-cresol, 3,
Xylenol represented by 5-xylenol,
Examples of para-substituted phenols include para-tertiary butylphenol, para-octylphenol, paraphenylphenol, and paracumylphenol. Monoepoxy compounds for converting phenolic hydroxyl groups into hydroxyl groups by reacting with the above polyhydric phenols or novolaks include, for example, ethylene oxide, propylene oxide, phenyl glycidyl ether, epichlorohydrin, styrene oxide, butyl glycidyl ether. , is typical. Furthermore, the prepolymer of the present invention can also be obtained by reacting an epoxy resin with a phenol. The epoxy resins and phenols that can be used here are those mentioned above. It is desirable that the reaction ratio between the epoxy group and the phenolic hydroxyl group is substantially 1:1. As the gel coat resin and the backing casting resin used in the present invention, radical curable resins such as unsaturated polyester resins, vinyl ester resins, and acrylic urethane resins can be used. Of course, the unsaturated urethane resin of the present invention described above can also be used. Various types of fillers are used depending on the required physical properties as the filler to be mixed with the backing casting resin. When transparency is required, fine glass powder, hydrated alumina (aluminum hydroxide), fine silica powder, etc. are useful. This is especially true when a thick FRP layer is laminated next to the surface gel coat layer, such as when hydrated alumina is mixed with a resin to make a casting resin, and the hardened cast product immediately whitens when boiled. As a result, it is also possible to utilize fillers that have not been used until now. If transparency is not required, calcium carbonate,
clay, alumina, mica, barite, gypsum,
Micro balloons etc. are selected as necessary. The coloring can be done freely, and the molding method can be carried out in a conventional manner. [Example] Next, in order to assist in understanding the present invention, examples are shown below. Example 1 Synthesis of glycidyl methacrylate-methacrylic acid adduct [a] 1 equipped with a stirrer, reflux condenser, and thermometer
Glycidyl methacrylate in a three-necked flask
280g (1.97mol), methacrylic acid 165g
(1.91 mol), 1.8 g of trimethylbenzylammonium chloride, and 0.2 g of methylparabenzoquinone were reacted at 100 to 105°C for 12 hours, and the acid value was
8.9, so I stopped and added 155g of styrene.
A styrene solution of glycidyl methacrylate and methacrylic acid adduct [a] (hereinafter abbreviated as adduct [a]) was obtained in the form of a light reddish brown liquid. Synthesis of unsaturated urethane resin [A] Styrene was added to a two-separable flask equipped with a stirrer, gas inlet tube, thermometer, and reflux condenser.
250g, diphenylmethane diisocyanate 220
g, 600 g of styrene solution of adduct [a] and 1.2 g of dibutyltin dilaurate were added and heated to 60°C for 4 hours.
When the reaction was carried out in a stream of dry air, infrared analysis confirmed that the absorption of isocyanate groups completely disappeared. The obtained unsaturated urethane resin [A] is reddish brown,
It was slightly cloudy and thixotropic with a viscosity of about 40 poise. A system containing 100 parts of resin [A], 1.5 parts of #328E from Kayaku Nouri Co., Ltd. as a hardening agent, and 1 part of cobalt naphthenate rapidly generated heat after gelling in 13 minutes, reaching a maximum temperature of 179°C. did. Add 1.5 parts of 328E and 0.2 parts of cobalt naphthenate to 100 parts of resin [A], and leave it to harden overnight.
The physical properties of the casting resin cured after 2 hours at °C are as shown in Table 1, showing excellent heat resistance and good hardness and strength. Table 1 Bending strength 13.9Kg/mm ^2Bending modulus of elasticity 490Kg/mm ^2Sharpy impact value 2.2Kg・cm/cm ^2Heat distortion temperature 187℃ Rotsuwell hardness (M scale) M-120 Manufacture of gel coat Unsaturated urethane resin ( A) 100 copies of Erosil R _x −
200 and 0.02 part of Phthalocyanine Blue were roll kneaded to form a gel coat. Creating a test piece Gel coat on a glass plate treated with a mold release agent.
Add 1.5 parts of Parkadox #16 to 100 parts and add 0.6m/
It was coated with a bar coater so that it had a coating thickness of m, and heated at 60℃ for 30 minutes to gel, and then prepared by adding 1.5 parts of Erosil R _x -200 and 1 part of Parkadox #16 to 100 parts of resin (A). Impregnate Glass Surf Esmat 30P with resin liquid and apply it next to the gel coat layer.
It was heated at 60°C for 30 minutes to form a gel. The thickness of the intermediate layer was approximately 0.8 mm. Use this as one side, and the other side with a thickness of 1 to 1.5 m/
m FRP board so that the thickness is about 8m/m,
2156 manufactured by Showa Kobunshi Co., Ltd. was used as the isophthalic acid polyester resin, and cast in a system containing 100 parts of this resin, 1.5 parts of Parkadox #16, and 200 parts of Frit manufactured by Nippon Ferro Co., Ltd. as a filler, and cast at 60°C for 2 hours. , heated at 80℃ for 2 hours to a thickness of about 10m/m,
A test piece of 300×300 m/m was obtained. The gel coated surface was brought into close contact with a boiling test container having holes of 100 m/m in diameter through silicone rubber packing, and a continuous boiling test was conducted in boiling water at 98 to 100°C. Example 2 Production of unsaturated urethane resin (B) Production of hydroxyl group-containing prepolymer [b] 2 equipped with a stirrer, reflux condenser, and thermometer
In a three-necked flask, add 260 g of Union Carbide's ERL-4221 as an epoxy resin, α-
Naphthol 280g, triphenylphosphine 2g
was charged, heated to 150 to 160°C, cooled if necessary, and reacted at 160°C for 8 hours. As a result of infrared analysis, it was confirmed that free epoxy groups had disappeared. Next, p-methylstyrene 460 at a temperature of around 120℃
g was added, and a prepolymer (epoxy resin-α naphthol adduct) [b] was obtained in the form of a pale reddish brown liquid. Production of isocyanate adduct [c] Add 440 g of isophorone diisocyanate and 260 g of p-methylstyrene to the total amount of prepolymer [b].
g and heated to 60℃, then added 3g of dibutyltin dilaurate and reacted at 60℃ for 6 hours.
As a result of infrared analysis, it appeared that the free isocyanate groups were reduced by almost half. Isocyanate adduct [c] was obtained in a pale reddish brown liquid state. Production of vinyl ester resin [d] 2 equipped with a stirrer, reflux condenser, and thermometer
ERL as epoxy resin in a three-necked flask
520g of -4221, 344g of methacrylic acid, 0.5g of hydroquinone, and 2.5g of triphenylphosphine were charged and reacted at 120 to 125℃ for 5 hours.The acid value was 7.4, so 740g of p-methylstyrene was added.
In addition, vinyl ester resin [d] was obtained in the form of a reddish brown liquid. Production of unsaturated urethane resin [B] 700 g of vinyl ester [d], 850 g of isocyanate adduct [c], 0.15 g of parabenzoquinone,
Add 2g of dibutyltin dilaurate and heat to 8 at 60℃.
After reacting for a period of time, infrared analysis confirmed that free isocyanate groups disappeared. The obtained unsaturated urethane resin [B] had a light reddish brown color and a viscosity of 39 poise. Hereinafter, a boiling test was conducted using the unsaturated urethane resin [B] in the same manner as in Example 1. Example 3 Production of unsaturated urethane resin [C] Synthesis of isocyanate adduct (e) 2 equipped with a stirrer, reflux condenser, and thermometer
An addition product obtained by adding 1 mole of propylene oxide to bisphenol A in a separable flask (represented by the following formula, abbreviated as BPA-11) 370g of dibutyltin dilaurate, 254g of styrene, 376g of hexamethylene diisocyanate, and 0.1g of parabenzoquinone were charged and reacted in dry air at 60°C for 3 hours, then 3g of dibutyltin dilaurate was added and reacted at 65 to 70°C for 3 hours. As a result of infrared analysis, it was assumed that 57% of the isocyanate groups had reacted. A pale yellow-brown isocyanate (e) was obtained. Production of vinyl ester resin (h) In a separable flask equipped with a stirrer, reflux condenser, thermometer, and gas inlet tube, the Dow Chemical Co., Ltd.
360 g of DEN-431, 172 g of methacrylic acid, and 1.5 g of trimethylbenzylammonium chloride were charged, and the reaction was carried out at 130 to 135° C. with vigorous stirring in an air stream. After 3 hours, the acid value reached 7.1, so the process was stopped, and 468 g of styrene and 0.25 g of hydroquinone were added to obtain vinyl ester resin (h) with a Hazen color number of 300 and a viscosity of 3.1 poise. Production of unsaturated urethane resin [C] 500 g of isocyanate adduct (e), 500 g of vinyl ester resin (h), 200 g of styrene, a stirrer,
The mixture was placed in a two-separable flask equipped with a reflux condenser, a gas inlet tube, and a thermometer, and reacted at 65 to 70°C for 6 hours. As a result of infrared analysis, it was confirmed that free isocyanate groups had disappeared. The obtained unsaturated urethane resin [C] had a Hazen color number of 350 and a viscosity of 11.4 poise. Hereinafter, a boiling test was conducted in the same manner as in Example 1 above. Example 4 Production of unsaturated urethane resin [D] Production of glycidyl methacrylate-methacrylic acid adduct (j) 317 g of glycidyl methacrylate was placed in a two-separable flask equipped with a stirrer, a reflux condenser, a thermometer, and a gas inlet tube. , methacrylic acid 183g,
Trimethylbenzylammonium chloride 4.2
g and 0.05 g of tolquinone were charged, and the reaction was carried out at 120 to 125° C. in an air stream with vigorous stirring.
The acid value reached 2 in 2 hours, so the reaction was stopped, 500 g of styrene was added, and the adduct (j) had a Hazen color number of 200.
Obtained with. Synthesis of isocyanate adduct (k) 2 equipped with a stirrer, reflux condenser, and thermometer
− Hydrogenated bisphenol in a separable flask
A590g, Isophorone diisocyanate 835g, styrene 500
g was charged, reacted in dry air at 60°C for 2 hours, further added 3 g of dibutyltin dilaurate, and reacted at 65-70°C.
The reaction was carried out at ℃ for 2 hours. As a result of infrared analysis, it was assumed that 60% of the isocyanate groups had reacted. A light yellowish brown isocyanate adduct (k) was obtained. Production of unsaturated urethane resin [D] Isocyanate adduct (K) 1928g, styrene
1000g, glycidyl methacrylate-methacrylic acid adduct (j) 1004g, dibutyltin dilaurate 9g
into a 5-separable flask equipped with a stirrer, a reflux condenser, a gas inlet tube, and a thermometer.
After reacting at 70°C for 6 hours, infrared analysis confirmed that free isocyanate groups had disappeared. The obtained unsaturated urethane resin [D] had a Hazen color number of 300 and a viscosity of 18 poise. Below, a boiling test was conducted in the same manner. Comparative Example A polyester resin (4) having the following formulation was produced. Weigh out 240 g (1 mol) of hydrogenated bisphenol A, 125 g (1.2 mol) of neopentyl glycol, and 166 g (1 mol) of isophthalic acid into a reaction vessel.
After esterification at 210℃ in a nitrogen stream to give an acid value of 30.1, 116g (1 mol) of fumaric acid was added, further esterification was carried out under the same conditions, and when the acid value was 34.7, 0.15g of hydroquinone was added, and styrene was added at a temperature of 155℃. 525g
was dissolved in water to obtain polyester resin (4). It had a viscosity of 4.7 poise and a Hazen color number of 350. Hereinafter, a boiling test was conducted in the same manner as in Example 1. The above results are summarized in Table 2.

〔Effect of the invention〕

According to the method of the present invention, it is possible to produce molded products that exhibit excellent boiling resistance at low cost, and are extremely useful for applications that require aesthetic appeal and water resistance, such as bathtubs, washstands, and tiles. .

[Brief explanation of drawings]

FIG. 1 is a drawing showing the cross-sectional structure of a cast product obtained by the method of the present invention.

Claims (1)

[Scope of Claims] 1. When a mold is coated with a gel coat and a molded product is obtained by lining the mold with a filler-containing resin, the next layer of the gel coat is (a) a woven fabric or non-woven fabric made of glass fiber, (b) A layer impregnated or coated with an unsaturated urethane resin containing at least two unsaturated urethane structures having at least two terminal unsaturated groups via urethane bonds is set as an intermediate layer. Characteristic method for manufacturing molded products.