JPH0375012B2 - - 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 tendency to 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 sufficiently 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, performs lining molding on the mold using a filler-containing resin, and when obtaining a molded product, the next layer of the gel coat is (a) glass. A woven or nonwoven fabric made of fibers, (b) has a (meth)acryloyl group in the side chain via a urethane bond or an ester bond, and the main chain is carbon-carbon.
By setting a layer impregnated or coated with a side chain unsaturated polymer having carbon bonds as an intermediate layer, the above-mentioned drawbacks are eliminated.
An object of the present invention is to provide a method for producing a molded article exhibiting excellent physical properties. [Function] To help understand the present invention, a cross section of a molded article according to the present invention is shown in FIG. The layer next to the gel coat is a filler-containing resin (a woven or non-woven fabric made of glass fibers is impregnated with a radical-curable polyester resin or vinyl ester resin, and is provided as an intermediate layer (surface reinforcing layer). A molded body (resin concrete) and a method for producing the same have already been proposed. The main purpose of the conventional method is to use filler-containing resin [resin concrete (abbreviated as resin concrete)] to
When used alone, it has the disadvantage of large shrinkage during curing and low tensile strength and bending strength, but by reinforcing one or both sides of the resin layer with fiber reinforced plastic (FRP), dimensional accuracy can be improved. It is an object of the present invention to provide a resin molded product having good quality and relatively light weight. However, the next layer after the gel coat, that is, the intermediate layer (surface reinforcing layer), is a woven fabric or nonwoven fabric made of glass fiber, and a radical curing type polyester resin or vinyl ester resin is applied to the woven fabric or nonwoven fabric made of glass fiber.
Because it is impregnated and painted, its water resistance and hot water resistance (boiling resistance) are insufficient, and after about 300 to 400 hours, yellowing, blistering, glass fiber fraying, and casting layer of the gel coat layer may occur. Whitening, etc. had occurred and the appearance had been significantly damaged. In the present invention, a side chain unsaturated polymer is used as the resin to be impregnated and applied to a woven fabric or nonwoven fabric made of glass fibers, so the main chain is a carbon-carbon bond,
Therefore, it has excellent hydrolysis resistance, and 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 high resistance to water after a boiling test. It is thought that the color tone and transparency will also be improved. Woven or non-woven fabrics made of glass fibers used in the present invention include glass cloth, chopped strands, glass mats, surfing mats, etc., and there are no particular restrictions on their density;
It is preferably 150 g/m ² or more, and preferably borane-treated or silane-treated. The side chain unsaturated polymer used in the present invention is a curable polymer having a (meth)acryloyl group in the side chain via a urethane bond or an ester bond, and the main chain is a carbon-carbon bond. A vinyl polymer having a functional group such as a hydroxyl group, a carboxyl group, or a glycidyl group is produced, and then the functional group is reacted with a compound that shares a reactive group that performs a urethanization or esterification reaction and a (meth)acryloyl group. Manufactured by Typical manufacturing methods and specific examples include the following. (1) A side chain unsaturated polymer having a (meth)acryloyl group via a side chain urethane bond (a) [A] side similar to those described in JP-A-59-230019 and JP-A-60-38403 A polymer containing a hydroxyl group in the chain and [B] an unsaturated isocyanate having a free isocyanate group which is an adduct of a polyvalent isocyanate and an unsaturated monoalcohol having a (meth)acryloyl group are polymerizable monomers. Examples include side-chain unsaturated polymers that can be cured by reacting the hydroxyl group of [A] and the isocyanate group of [B] in the body. Among them, polymers represented by the following general formula [] are preferably used in the present invention. [However, R ₁ and R ₂ are hydrogen or a methyl group, G represents a diisocyanate residue, M is 50 to 300, n is 70 to 99, and m is 1 to
30, l is an integer of 2 or 3. ] Specifically, a copolymer of 2-hydroxylethyl (meth)acrylate or 2-hydroxypropyl (meth)acrylate and styrene was used as a polymer containing a hydroxyl group in the side chain, and tolylene difluoride was used as an unsaturated isocyanate. Most suitable are those obtained by reacting a 1:1 molar adduct of isocyanate with 2-hydroxyethyl (meth)acrylate or 2-hydroxypropyl (meth)acrylate. (b) A curable side chain unsaturated polymer obtained by reacting the aforementioned polymer containing a hydroxyl group in the side chain with (meth)acryloyloxyethyl isocyanate can be mentioned. (c) A polymer containing isocyanate in the side chain obtained by copolymerizing (meth)acryloyloxyethyl isocyanate with other vinyl monomers such as styrene and methyl methacrylate, and an unsaturated polymer having a (meth)acryloyl group. Examples include side chain unsaturated polymers obtained by reacting with alcohol. (2) a side chain unsaturated polymer having a (meth)acryloyl group in the side chain via an ester bond; (d) a polymer having a glycidyl group in the side chain;
It is a side chain unsaturated polymer obtained by reacting with (meth)acrylic acid, and the polymer represented by the following general formula [] is typical. [However, the definitions of R ₁ , R ₂ , M, n and m are the same as above. ] Specifically, (meth) is added to a copolymer of styrene and glycidyl (meth)acrylate.
Preferably, it is obtained by subjecting acrylic acid to an esterification reaction. Moreover, those using allyl glycidyl ether instead of glycidyl (meth)acrylate are also preferably used. (e) a polymer containing a carboxyl group in its side chain;
Examples include polymers represented by the above general formula [] obtained by reacting with an unsaturated epoxy compound. Specifically, a material obtained by reacting a copolymer of styrene and (meth)acrylic acid with glycidyl (meth)acrylate is suitable. (F) [A] For 1 mole of (meth)acrylic acid, as typified by JP-A No. 61-258817 "Curable resin and method for producing the same",
A component containing as at least one component an unsaturated epoxy resin having a (meth)acryloyl group and an epoxy group in the molecule obtained by reacting 1 mole or more of an epoxy resin with a vinyl monomer using a radical polymerization catalyst. By copolymerizing, a polymer-containing reaction mixture having an epoxy group in the side chain of the resulting polymer is created, and then [B] substantially equimolar amount of the epoxy group remaining in the reaction mixture obtained from step [A]. Examples include side-chain unsaturated polymers obtained by adding (meth)acrylic acid and reacting epoxy groups with carboxyl groups. Among these, polymers represented by the following general formula [] are preferred. [However, R ₁ , R ₂ , M, n, and m are the same as above. R ₃ and R ₄ are hydrogen or a methyl group, and p is an integer of 0 to 5. ] Similarly, in place of the bisphenol type epoxy resin, a novolac type epoxy resin or an alicyclic epoxy resin may also be suitably used. (g) Polymers containing carboxyl groups in their side chains,
Examples include side-chain unsaturated polymers represented by the general formula [] obtained by reacting the above-mentioned unsaturated epoxy resins. The epoxy resin used is the same as above. (H) A side chain unsaturated polymer obtained by reacting an unsaturated alcohol having a (meth)acryloyl group with a polymer having an acid anhydride group in the side chain can be mentioned. Among them, polymers represented by the following general formula [] are preferably used. [However, R ₁ , R ₂ , n, m and M are as described above. ] Specifically, a copolymer of styrene and maleic anhydride is used as a polymer having an acid anhydride group, and it is obtained by reacting it with 2-hydroxyethyl (meth)acrylate or 2-hydroxypropyl (meth)acrylate. The best option is the one that can be used. Furthermore, a polymer free of free carboxyl groups obtained by reacting the free carboxyl groups resulting from esterification with an epoxy group or a monomer sharing a hydroxyl group and a (meth)acryloyl group is also applicable to the method of the present invention. It can be used in The above side chain unsaturated polymers have a molecular weight of 5000 or more,
Desirably 10,000 or more and 100,000 or less. If the molecular weight is less than 5,000, the curing properties and physical properties are not necessarily sufficient, and if it is more than 100,000, the viscosity becomes high and workability becomes poor. The ratio of (meth)acryloyl groups in the side chain unsaturated polymer is preferably 1 mol% or more and 30 mol% or less. The most suitable range is 5 mol% or more and 20 mol% or less. 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 aforementioned side-chain unsaturated polymers of the present invention 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, glass fine powder, hydrated alumina (aluminum hydroxide), silica fine 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 help the understanding of the present invention, examples are shown below. Example 1 Production of side chain unsaturated polymer (a) having a (meth)acryloyl group in the side chain via a urethane bond In a No. 3 autoclave capable of heating and cooling,
Styrene, hydroxyethyl methacrylate, t
Predetermined amounts of -dodecylmercaptan and n-dodecylmercaptan were charged, and copolymerization was carried out at a predetermined temperature. Samples were taken periodically and the molecular weight was determined. When a predetermined molecular weight is reached, a predetermined amount of a diluent consisting of styrene as a diluent monomer, hydroquinone as a polymerization inhibitor, and dibutyltin dilaurate as a catalyst is poured into an autoclave and heated at 60°C.
The mixture was stirred for 0.5 hour while maintaining the temperature. Next, an equivalent amount of an unsaturated isocyanate sharing a methacryloyl group and an isocyanate group was added to the molecule obtained by reacting 130 parts of tolylene diisocyanate and 150 parts of 2-hydroxypropyl methacrylate, and the mixture was heated to 60°C. Urethane formation was carried out until the isocyanate groups disappeared. The reaction time was approximately 6 hours. 1.5 parts of peroxide catalyst (manufactured by NOF Corporation, Percure SA) and 0.5 parts of cobalt naphthenate (containing 6% cobalt) were added to 100 parts of the obtained curable resin, and the mixture was cured at room temperature and the physical properties were measured. did.

[Table] Manufacture of gel coat 100 parts of side chain unsaturated polymer (a), Erosyl R _x −
4 parts of 200 and 0.02 part of phthalocyanine blue were roll-kneaded to obtain gel coat (A). Preparation of test piece (a) Gel coat on glass plate treated with mold release agent.
Add 1.5 parts of Parkadox+16 to 100 copies, 0.6
Paint with a bar coater so that the ratio is m/m, and heat at 60℃30
After heating for a few minutes to gel, the side chain unsaturated polymer
(a) With a resin liquid prepared by adding 1.5 parts of Erosil R _x -200 and 1 part of Parkadox #16 to 100 parts,
Glass Surf Esmat 30p was impregnated, applied next to the gel coat layer, and heated at 60°C for 30 minutes to 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. Heat it at 80℃ for 2 hours to a thickness of about 10m/m,
A test piece (A) of 300 x 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 In the same polymer as in Example 1 having a hydroxyl group in the side chain, 116 was added as an unsaturated isocyanate instead of the reaction product of tolylene diisocyanate and 2-hydroxypropyl methacrylate.
A side chain unsaturated polymer (b) was synthesized by carrying out the same reaction as in Example 1 except for using isocyanatoethyl methacrylate. Thereafter, a test piece was prepared in the same manner as in Example 1, and a boiling test was conducted. Example 3 Production of side chain unsaturated polymer (c) Toluene was placed in a two-separable flask equipped with a stirrer, reflux condenser, thermometer, and gas inlet tube.
1000 g of styrene, 400 g of styrene, 60 g of isocyanate ethyl methacrylate, 5 g of styrene dimer, and 1 g of azobisisobutyronitrile were charged, and the mixture was replaced with _N2 for 30 minutes. During this time, the temperature of the liquid was raised to 90°C, and polymerization was carried out at this temperature for 4 hours. The polymerization rates of styrene and isocyanatoethyl methacrylate by gas chromatography were 63% and 73%, respectively.
%, and the weight average molecular weight by liquid chromatography is 5.3
It was ×10 ⁴ . Lower the liquid temperature to 60°C, add 130 parts of hydroxyethyl methacrylate, 1 part of dibutyltin dilaurate, and 0.1 g of phenothiazine.
The urethanization reaction was carried out at ℃ for 5 hours until the isocyanate group disappeared. An additional 60 parts of styrene was added, and toluene was distilled off under reduced pressure to obtain a side chain unsaturated polymer (iii). Hereinafter, a boiling test was conducted in the same manner as in Example 1. Example 4 Production of side chain unsaturated polymer (2) having (meth)acryloyl group via side chain ester bond Production of unsaturated epoxy resin (a) Stirrer, thermometer with gas inlet tube, reflux condenser, dropping In a separable flask equipped with a funnel, 360 g (1 mol) of Mitsubishi Yuka-Ciel's Epicote 827 as an epoxy resin and 43 g of methacrylic acid.
(0.5 mol), benzyldimethylamine 1.2 g, and parabenzoquinone 0.08 g are reacted for 3 hours at 120-130°C under nitrogen blowing conditions. The acid value becomes almost zero and the unsaturated epoxy resin (a) turns into a light reddish brown syrup. Obtained as follows. For resin (a), the following formula [] is calculated as 223g, It is a mixture with 180 g of free epoxy resin. Synthesis of side chain epoxy resin (b) Into the same apparatus as above, 250 g of methyl ethyl ketone,
173 g (0.2 mol) of unsaturated epoxy resin (a), 100 g of styrene, and 3.5 g of azobisisobutyronitrile were charged, and 87 g of styrene (total amount of styrene: 1.8 mol) was added dropwise at 75°C in a nitrogen stream. After 6 hours, add 2 more azobisisobutyronitrile
g was added, and the polymerization was further continued for 10 hours. When the polymerization rate reaches 96%, hydroquinone
Polymerization was stopped by adding 0.2 g. A solution of side chain epoxy resin (b) in methyl ethyl ketone (solid content 40%) was obtained in the form of a pale yellowish brown liquid. G.P.C.
As a result of the analysis, it was confirmed that it was a mixture of a polymer having a peak at a molecular weight of about 50,000 and an unreacted epoxy resin. Synthesis of side chain unsaturated polymer (d) Add 52 g (0.60 mol) of methacrylic acid to the entire methyl ethyl ketone solution of the side chain epoxy resin (b) described above.
When 0.8 g of triphenylphosphine is charged and reacted for 16 hours at the boiling point of methyl ethyl ketone, the acid value is
10.4, 420 g of styrene monomer was added and heated under reduced pressure of 400 to 450 mmHg to remove methyl ethyl ketone. After about 6 hours, gas chromatographic analysis showed that methyl ethyl ketone was 0.3%, so heating was discontinued, and side chain unsaturated polymer (d) was obtained with a yellowish brown color and a viscosity of 1.9 poise. Side chain unsaturated polymer (d) 100 parts Perkyure SA (manufactured by NOF Corporation) (peroxide catalyst)
A mixture of 1 part cobalt naphthenate (6% Co) and 0.5 parts was gelled at room temperature for 11 minutes, with a minimum cure time of 11.4 minutes and a maximum exotherm temperature of 157°C. The cured resin had the following excellent physical properties: Tensile strength (Kg/mm ² ) 6.9-7.4 Bending strength (Kg/mm ² ) 13.7-15.9 Bending modulus of elasticity (Kg/mm ² ) 322-369 Heat distortion temperature (°C) 124 A test piece was prepared in the same manner as in Example 1 and a boiling test was conducted. Example 5 Production of a side chain unsaturated polymer (e) having a (meth)acryloyl group via an ester bond in the side chain [Production of styrene-glycidyl methacrylate copolymer] Equipped with a pressure regulator, a pressure gauge, and a safety valve. Inner diameter 4
Styrene (76% by weight) and glycidyl methacrylate (23% by weight) were placed in a stainless steel reactor with mmφ and length of 1.5m.
wt%), n-dodecyl mercaptan (1 wt%)
A mixture of
The reaction was carried out under conditions of 7 Kg/cm ² . As a result, the reaction rate of styrene was 58%, the reaction rate of glycidyl methacrylate was 73%, and a colorless and transparent sticky copolymer composition was obtained. [Production of side chain unsaturated polymer (e)] In a separable flask (1000 ml) equipped with a stirrer, thermometer, and reflux condenser, add the above copolymer composition (200 g), styrene (200 g), and methacrylic acid (27.9 g). g, 0.32 mol) and hydroquinone (0.2 g), and the mixture was reacted at 100°C for 5 hours. As a result, the reaction rate of methacrylic acid was 95%, and the resulting solution of the side chain unsaturated polymer (e) was pale yellow and transparent, and the viscosity at 25°C was 15 poise. 1 part of "Permec N" (trade name, peroxide catalyst manufactured by NOF Corporation) per 100 parts of the above polymer solution,
When 0.5 part of cobalt naphthenate (6% Co) was added and a room temperature gelling test was performed, gelation time was 12 minutes,
The shortest curing time was 14.3 minutes, and the maximum exothermic temperature was 140°C. Further, the cured resin had the following physical properties and was excellent in transparency. Tensile strength 7.4Kg/mm ² Bending strength 15.9Kg/mm ² Bending modulus of elasticity 369Kg/mm ² Heat distortion temperature 125° Hereinafter, the same method as in Example 1 was performed using the solution of the above side chain unsaturated polymer (e). A boiling test was conducted. Example 6 Production of side chain unsaturated polymer (f) having (meth)acryloyl group via side chain ester bond [Production of styrene-methacrylic acid copolymer] Inner diameter equipped with pressure regulator, pressure gauge, and safety valve 4
Styrene (76% by weight), methacrylic acid (23% by weight), n-
A mixture of dodecyl mercaptan (1% by weight) was supplied at a rate of 2.0 g/min, and the reaction was carried out at 200° C. and 5 to 7 kg/cm ² . As a result, the reaction rate of styrene was 57% and the reaction rate of methacrylic acid was 72%, and a colorless and transparent sticky copolymer composition was obtained. [Production of side chain unsaturated polymer (F)] The above copolymer composition (200 g), styrene (200 g), and glycidyl methacrylate (76.0 ) and hydroquinone (0.2 g) were added and reacted at 100°C for 5 hours. As a result, the reaction rate of glycidyl methacrylate was 93%, and the resulting solution of the side chain unsaturated polymer (f) was pale yellow and transparent, and the viscosity at 25°C was 9 poise. 1 part of "Permec N" (trade name, peroxide catalyst manufactured by NOF Corporation) per 100 parts of the above polymer solution,
When 0.5 part of cobalt naphthenate (6% Co) was added and a room temperature gelling test was performed, gelation time was 11 minutes,
The shortest curing time was 11.4 minutes, and the maximum exothermic temperature was 156°C. Furthermore, the cured resin had the following physical properties and was excellent in transparency. Tensile strength 7.0Kg/mm ^2Bending strength 13.8Kg/mm ^2Bending modulus of elasticity 323Kg/mm ^2Heat distortion temperature 125°C Below, using the solution of the side chain unsaturated polymer (f) above, the same procedure as in Example 1 was carried out. A boiling test was conducted using the method. Example 7 Synthesis of side chain unsaturated polymer (g) having methacryloyl group in side chain via ester bond, stirrer,
In a two-separable flask equipped with a reflux condenser, a gas inlet tube with a thermometer, and a dropping funnel, add 728 g of styrene, 10 g of t-butyldodecyl mercaptan,
A mixture of 200 g of methyl methacrylate and 98 g of maleic anhydride was added dropwise at a temperature of 100° C. in a nitrogen stream. After the dropwise addition was started, the temperature was raised to 120°C, and the dropwise addition was completed at the same temperature for 4 hours. After finishing dropping,
If you continue heating at the same temperature for another hour, the solid content will be 45
(%) In molecular weight measurement by GPC
The peak was at 28,000. Lower the temperature to 100℃, add 0.2 g of hydroquinone, 130 g of 2-hydroxyethyl methacrylate, and 2 g of p-toluenesulfonic acid, and react at the same temperature for 6 hours. As a result of infrared analysis, the absorption of acid anhydride in the polymer was approximately 70
(%) was judged to have disappeared. A side chain unsaturated polymer (T) was obtained with a viscosity of 5.4 poise and a Hazen color number of 300. Hereinafter, a boiling test was conducted in the same manner as in Example 1. Comparative Example A polyester resin (H) having the following formulation was produced. Weigh out 240 g (1 mol) of hydrogenated bisphenol A, 125 g (1.2 mol) of neobentyl 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
It was dissolved in to form a polyester resin (H). It had a viscosity of 4.7 poise and a Hazen color number of 350. A boiling test similar to that in the example was conducted. The above results are summarized in Table 2.

[Table] [Effects of the Invention] According to the method of the present invention, it is possible to manufacture molded products exhibiting extremely excellent boiling resistance at low cost, and is suitable for use in bathtubs, washstands, tiles, etc. that require aesthetic appeal and water resistance. It is extremely useful for many applications.

[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)

[Claims] 1. Gel coat is applied to the mold, backing molding is performed using resin mixed with filler to obtain a molded product, and the next layer of gel coat is (a) a woven fabric or non-woven fabric made of glass fiber. (b) has a (meth)acryloyl group in the side chain via a urethane bond or an ester bond, and the main chain is carbon-carbon.
A method for manufacturing a molded article, characterized in that a layer impregnated or coated with a side chain unsaturated polymer having carbon bonds is set as an intermediate layer.