JPS6129980B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to resin compositions, and in particular, unsaturated polyester resins, thermoplastic resins,
It consists of an aliphatic carboxylic acid with a total carbon number of 3 to 50 and a fine powder filler with a specific surface area of 15000 cm ² /g or more, and has excellent storage stability, filler sedimentation prevention properties, and resin separation prevention properties. The present invention relates to a resin composition that exhibits little volume change during curing and has excellent crack prevention properties. Generally, unsaturated polyester resins include fumaric acid,
α/β-unsaturated dibasic acids such as maleic anhydride, itaconic acid, etc. or mixtures thereof with saturated dibasic acids such as phthalic acid, phthalic anhydride, isophthalic acid, adipic acid, etc., and ethylene glycol, propylene glycol, etc. It is prepared by mutually dissolving an unsaturated polyester obtained by a dehydration condensation reaction with a polyhydric alcohol such as styrene, a polymerizable vinyl monomer as a crosslinking agent such as vinyltoluene, etc. By using an organic peroxide such as oxide as a polymerization catalyst and, if necessary, an organic metal salt such as cobalt octenoate or cobalt naphthenate as a polymerization accelerator, polymerization and curing can be carried out together with glass fibers, inorganic fillers, and pigments. The cured resin product has excellent mechanical strength, chemical resistance, and heat resistance, so it is used in a wide range of fields such as FRP, casting, painting, decorative boards, resin concrete, and resin mortar. being used effectively. And the demand for it is rapidly increasing. However, with general unsaturated polyester resin,
Shrinkage during curing is extremely high at 4-12% by volume.
When using styrene as a crosslinking agent, it is
It is difficult to reduce the shrinkage to less than % by volume, and this shrinkage has a serious drawback in that cracks and warpage occur in molded products in various molding methods. In order to solve these drawbacks, we have developed a composition that is soluble in the polymerizable vinyl monomer constituting a specific unsaturated polyester resin, but which is optically inhomogeneous if present during polymerization and curing of the resin. Resulting polymerizable reactive group
A low-shrinkage liquid resin composition has been proposed comprising a thermoplastic polymer derived from a substance having CH ₂ =C< or a mixture thereof. The proposed low-shrinkage liquid resin composition has low shrinkage upon curing and overcomes the above-mentioned drawbacks, and can be used in sheet molding compound (SMC) molding, bulk molding compound (BMC) molding, or resin composition. It is widely used in concrete compositions, etc. Recently, this low-shrinkage liquid resin composition has been used in pultrusion molding, filament winding (FW) molding,
Applications have come to be considered in molding fields such as preform matted die molding, matt matted die molding, cold press molding, casting, etc., that is, molding fields using molding materials with relatively low viscosity. However, in these molding methods, this low shrinkage liquid resin composition has several drawbacks.
For example, when performing pultrusion molding or filament winding (FW) molding using a low-shrinkage liquid resin composition or a resinous composition that combines the composition and a filler, the thermoplastic resin polymerizes in the impregnation bath. It has the disadvantage that it cannot always be molded with a uniform material composition because it separates from the vinyl monomer and floats out, or if it contains a filler, the filler settles.
Furthermore, they also have the disadvantage that the mold may be contaminated by the thermoplastic resin separated during the curing process, and the surface of the molded product may become rough. Furthermore, when performing cold press molding, preform matte die molding, or matte matte die molding, there are disadvantages such as non-uniformity due to separation of thermoplastic resin and contamination of the mold by separated thermoplastic resin. . In addition, when casting, a transparent or opaque layer consisting of a thermoplastic resin and a polymerizable vinyl monomer is formed on the surface, and the polymerization and curing of this layer is extremely slow, making it undesirable for work. . As a result of extensive research in order to overcome the serious drawbacks of resinous compositions as mentioned above, one of the present applicants found that the number of carbon atoms per carboxyl group is 2 to 25 and the total number of carbon atoms is Resin compositions containing 3 to 50 aliphatic carboxylic acids and having a viscosity of 2.0 poise or higher have excellent separation stability of thermoplastic resins and anti-sedimentation properties of fillers. Based on this knowledge, he filed a patent application (Japanese Patent Application Laid-open No. 54686/1986). However, as a result of further research, it was found that the technology of the above-mentioned application still had the following problems. That is, when a conventional filler is blended into the resin composition as described above, the volume content of the reinforcing material in the molded product obtained by impregnating the resin composition with a reinforcing fiber material or the like decreases, resulting in a considerable decrease in strength. Moreover, in order to effectively utilize the same amount of reinforcing material, it is necessary to use a larger amount of resin/filler composition than in the conventional example, and as a result, the cost reduction effect, which is one of the purposes of using filler material, cannot be expected to be very effective. This was confirmed. Based on the above-mentioned knowledge, the present inventors have developed a technology that can prevent a decrease in the strength of the final molded product and an increase in the amount of resin/filler composition used, and can maximize the effect of adding the filler. Further studies have been carried out in an attempt to develop this. As a result, it was found that the above-mentioned defects are significantly affected not only by the viscosity of the resin/filler composition or the molding method, which have been pointed out in the past, but also by the specific surface area of the filler used. In other words, even if the resin used is the same, if the specific surface area of the filler is about the same as that of the conventional example, the above-mentioned drawbacks will clearly appear, but if the specific surface area of the filler is 15000 cm 2 /g or more, extremely fine fillers with a specific surface area of 15,000 cm ² /g or more It has been confirmed that the above-mentioned drawbacks can be almost completely eliminated by using the present invention, and the present invention has finally been completed. That is, the composition of the resinous composition according to the present invention is (A) an unsaturated polyester, (B) a monomer having an unsaturated group (B), and (C) a thermoplastic that is compatible with the above (B). resin (hereinafter simply referred to as thermoplastic resin (C)), (D) aliphatic carboxylic acid having 2 to 25 carbon atoms per carboxyl group and 3 to 50 carbon atoms in total ( (E) An inorganic or organic fine powder filler having a specific surface area of 15,000 cm ² /g or more is added to 100 parts by weight of a liquid unsaturated polyester resin composition consisting of an aliphatic carboxylic acid (D). It is formulated in a proportion of 10 parts by weight or more, and has excellent properties in preventing sedimentation of fillers, preventing separation of thermoplastic resins, and storage stability, and is particularly effective in various types of reinforcement. When manufacturing molded products by using it in combination with reinforcing materials, it is possible to prevent the volume content of reinforcing materials from decreasing, resulting in molded products with excellent strength, and to minimize the amount of resin and filler composition used. A resinous composition that can reduce the amount of water and provide molded products at low cost has now been obtained. Unsaturated polyester (A) used in the present invention
For example, a polyhydric alcohol is mixed with an α/β-unsaturated dibasic acid or a mixture thereof with a saturated dibasic acid in a stream of an inert gas such as carbon dioxide or nitrogen gas. A method in which the condensation reaction is carried out by heating to 140 to 250°C, and the temperature is gradually raised according to the degree of reaction progress while distilling the produced water out of the reaction system, α / β-unsaturated dibasic acid anhydride or the like A method in which a mixture of saturated dibasic acid anhydride and oxide is heated to 50 to 250°C in an inert gas stream without or in the presence of a catalyst to react with α/β-
Some or all of the unsaturated dibasic acids or their mixtures with saturated dibasic acids may be replaced by esters of lower alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, etc. of these acids and/or by the substitution of polyhydric alcohols. Part or all of the polyhydric alcohol is replaced with an ester of lower fatty acids such as acetic acid or propionic acid, and the resulting water is heated to 140 to 250°C in the presence of a transesterification catalyst in an inert gas stream to undergo a condensation reaction. It is an unsaturated polyester having an acid value of 60 or less and a molecular weight of 1000 or more, which is obtained according to a method such as a method in which the temperature is gradually increased depending on the degree of reaction progress while distilling alcohol etc. out of the reaction system. In this case, the α/β-unsaturated dibasic acids used include maleic acid, halogenated maleic acid, fumaric acid, citraconic acid, itaconic acid, halogenated itaconic acid, and acid anhydrides of these acids. Dibasic acids include phthalic acid, halogenated phthalic acid, phthalic anhydride, halogenated phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, 3,6-endomethylenetetrahydrophthalic acid, succinic acid, adipic acid, and glutaric acid. acid, pimelic acid, corkic acid, azelaic acid, sebacic acid, etc. In addition, if necessary, monobasic acids such as acrylic acid, methacrylic acid, propionic acid, butyric acid, valeric acid, higher fatty acids, benzoic acid, octylic acid, etc., tetracarboxylic acids such as trimellitic acid, hemimelittic acid, trimesic acid, benzene, etc. It is also possible to use a polybasic acid such as the above-mentioned α/β-unsaturated dibasic acid or a mixture thereof with a saturated dibasic acid as a modifying agent. Polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1.
Examples include 3-butylene glycol, tetramethylene glycol, 1,6-hexanediol, neopentyl glycol, hydrogenated bisphenol A, and ethylene oxide and/or propylene oxide adducts of bisphenol A. It is used in a substantially equivalent amount to an excess amount of about 5 to 20 mol%. Further, if necessary, higher aliphatic alcohols such as amyl alcohol, hexyl alcohol, benzyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, etc., monohydric alcohols such as tetrahydrofurfuryl alcohol, glycerin, pentaerythritol, trimethylol ethane, etc. Polyhydric alcohols such as trimethylolpropane, trimethylolbutane, sorbitol, erythritol, mesoerythritol, etc. can also be used in combination with the above polyhydric alcohols as a denaturing agent. Examples of oxides include alkylene oxides such as ethylene oxide, 1,2-propylene oxide, and epichlorohydrin, glycidyl ethers such as methyl glycidyl ether, ethyl glycidyl ether, allyl glycidyl ether, methyl glycidyl ester, ethyl glycidyl ester, and allyl oxide. Glycidyl esters such as glycidyl esters and the like can be mentioned. In preparing the unsaturated polyester (A), α・
When adopting a method of reacting a β-unsaturated dibasic acid anhydride or a mixture thereof with a saturated dibasic acid anhydride with an oxide, the catalysts used are lithium, sodium, potassium, magnesium, calcium, and strontium. , barium, aluminum, thallium, lead, titanium, zirconium, antimony, zinc, cadmium, tin,
Examples include organic or inorganic salts of metals such as mercury, and esters of these metal acids with alcohols, and one or more of these may be used.
It can be effectively used in amounts of 5.0-0.01%, preferably 1.0-0.03%. In addition, when a method of transesterification is adopted, the transesterification catalyst used can be any of the catalysts used in the above method, and compounds of zinc, tin, antimony, and titanium have particularly high catalytic activity. preferable. The monomer (B) having an unsaturated group used in the present invention is one that is copolymerized with an unsaturated polyester and acts as a crosslinking agent, such as styrene, halogenated styrene, α-methylstyrene, vinyltoluene, divinylbenzene, Esters of vinyl acetate, acrylic acid or methacrylic acid with aliphatic alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, octyl alcohol, hexanol, tetrahydrofurfuryl alcohol, ethylene glycol, propylene glycol, etc., diallyl phthalate, etc. may be mentioned. I can,
One or a mixture of two or more of these monomers can be used in an amount of 20 to 300 parts by weight per 100 parts by weight of the unsaturated polyester. The thermoplastic resin (C) is compatible with the monomer (B) having an unsaturated group, and is uniformly present and dispersed in the cured resin composition. Examples of such thermoplastic resins (C) include polymerizable reactive groups such as styrene, vinyl chloride, vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, _acrylamide , etc. A homopolymer or copolymer of a monomer having , hydroxyethyl methacrylate, hydroxypropyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, methylol acrylamide, copolymers with methylol methacrylamide, etc. Among these, unsaturated polyester (A) and unsaturated group Thermoplastic resins that become optically non-uniform when mixed with monomer (B) having the following or when (A) and (B) undergo a curing reaction can be particularly effectively used. In addition to this, styrene/
Acrylonitrile copolymers, butadiene/acrylonitrile copolymers, saturated polyesters, and the like can also be used effectively. The molecular weight of thermoplastic resin (C) ranges over a wide range,
4,000 to 1,000,000, and the amount used is 1 to 40 parts by weight based on 100 parts by weight of the total amount of unsaturated polyester (A) and monomer having an unsaturated group (B). be able to. Aliphatic carboxylic acid (D) used in the present invention
is a monomer or di-trimer having 2 to 25 carbon atoms per carboxyl group and 3 to 50 carbon atoms in total, regardless of whether it is a naturally occurring acid or a synthesized acid. All can be used. Such acids include, for example, propionic acid, butyric acid, valeric acid, caproic acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, behenic acid. acids, saturated aliphatic monocarboxylic acids such as serotenic acid, acrylic acid,
Unsaturated aliphatic monocarboxylic acids, such as methacrylic acid, penteitic acid, hexonoic acid, tuccinic acid, linderic acid, lauroyl acid, oleic acid, elaidic acid, linoleic acid, linoleic acid, eleostearic acid, arachidonic acid, etc., adipine acids, saturated aliphatic dicarboxylic acids such as succinic acid, glutaric acid, pimelic acid, corkic acid, azelaic acid, sebacic acid, etc., olefins and maleic anhydrides such as dodecylsuccinic acid, pentadodecylsuccinic acid, octylsuccinic acid, etc. Examples include alkenylsuccinic acid derived from One type or a mixture of two or more types can be effectively used. Since mixtures of two or more acids can be effectively used, fatty acids obtained by hydrolyzing natural oils, dimers of the acids, hydrogenated products of the acids, alkenylsuccinic acids, etc. can be used as single acids. There is no need to take it out and purify it, and the reaction product mixture can be used as it is. The filler (E) used in the present invention is an inorganic or organic fine powder filler, such as calcium carbonate, magnesium carbonate, barium sulfate,
Calcium sulfate, alumina, clay, kaolin,
Talc, diatomaceous earth, silica gel, mica powder,
Examples include glass fiber powder, asbestos powder, Rockwell powder, silica powder, etc. These can be used alone or in combination of two or more, but in any case, the specific surface area is 15000 cm ² /g or more. Mr,
It must be used in extremely fine powder form. However, if a relatively coarse filler with a specific surface area of less than 15,000 cm ² /g is used, as mentioned above, when used in combination with a reinforcing material such as glass fiber, the volume content of the reinforcing material in the molded product The strength of the molded product decreases significantly. Moreover, in order to effectively use the same amount of reinforcing material, it is necessary to use a considerably larger amount of the resin/filler composition than in the case of using only the resin, which causes an economic disadvantage.
However, if a fine powder filler with a specific surface area of 15,000 cm ² /g or more is used, a strong molded product can be obtained without reducing the volume content of the reinforcing material.
and a resin/filler composition (resin composition of the present invention)
The amount of resin used can be reduced to approximately the same level as when resin is used alone. Although it is not necessarily clear why such an extreme difference appears due only to the difference in the specific surface area of the filler, the fine filler with an extremely large specific surface area is almost colloidal in the liquid unsaturated polyester resin composition. It is dispersed in
This is thought to be because the filler can freely move through the gaps within the reinforcing material together with the resin liquid. However, coarse fillers with a small specific surface area are dispersed in the resin liquid in a suspension-like manner, and because of their large particle size, they cannot move freely through the gaps within the reinforcing material. It is thought that the volume content of the reinforcing material decreases as a result of the reinforcing material entering and fixing the reinforcing material and expanding the gap between the reinforcing materials. For this reason, in the present invention, it is essential to use a filler having a specific surface area of 15,000 cm ² /g or more. Aliphatic carboxylic acid (D) used in the present invention
The amount used is the total amount of unsaturated polyester (A), monomer with unsaturated group (B) and thermoplastic resin (C) 100
It can range from 0.1 to 15 parts by weight, preferably from 0.5 to 10 parts by weight. In this case, if the amount is as small as 0.1 parts by weight or less, separation of the thermoplastic resin in the resinous composition will occur, making it impossible to achieve the purpose of the present invention, and even if the amount is as large as 15 parts by weight or more, it will be proportional to the amount. This is undesirable because the desired effect cannot be expected, and the effect of reducing shrinkage tends to decrease, and performance in terms of strength and water resistance tends to deteriorate. In addition, the amount of filler (E) used is as follows: (A), (B),
(C) and (D) should be blended in an amount of 10 parts by weight or more per 100 parts by weight of the liquid unsaturated polyester resin composition, and the optimum blending ratio may vary depending on the type of filler. Although it varies, it is generally advantageous to select from the range 20 to 80 parts by weight. However, the amount of filler is determined as appropriate depending on the purpose of reducing raw material costs, adjusting viscosity, and improving the physical properties required for cured products (molded products), but if it is less than 10 parts by weight, the effect of its addition will be negligible. However, if it is blended in an extremely large amount (for example, an amount equal to or more than the liquid unsaturated polyester resin composition), the viscosity of the entire composition will become too high to be used in practical use, and the impact strength of the molded product will be significantly reduced. This is not desirable as it will decrease. The resin composition of the present invention is used in combination with a reinforcing material such as glass fiber, and in consideration of convenience in use, it is preferable to adjust the viscosity to a range of 2.0 to 50 poise. . The resinous composition of the present invention is an unsaturated polyester.
(A), monomer with unsaturated group (B), thermoplastic resin
(C), an aliphatic carboxylic acid (D) and a filler (E), and can be easily prepared according to known procedures in synthetic resin manufacturing technology. For example, an unsaturated polyester (A) and a monomer (B) having an unsaturated group are dissolved in a resin liquid () and a thermoplastic resin (C) is mixed with a monomer (B) having an unsaturated group. Dissolved resin liquid () is prepared in advance, and at the stage of actual use, the resin liquid (2), aliphatic carboxylic acid (D), and filler (E) are uniformly mixed in a powerful mixer. It can be easily obtained by mixing it with The resinous composition according to the invention can be cured using organic peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, kyumene hydroperoxide, cyclohexanone peroxide, lauroyl peroxide, etc. or radicals such as azobisisobutyronitrile. If necessary, organic metal salts such as cobalt naphthenate, cobalt octenoate, aliphatic amines, aromatic amines,
It can be carried out by adding a polymerization accelerator such as mercaptans and following a conventionally known procedure. At this time, there is almost no volumetric contraction, and depending on the case, there may be expansion. The polymerization catalyst and accelerator may be added directly to the unsaturated polyester resin composition, or may be added to either the resin solution () or the resin solution () above together with the aliphatic carboxylic acid and filler. Both resin liquids can also be mixed and incorporated into the resin composition by transfer of the polymerization catalyst or accelerator, in an amount such that the resin liquid remains fluid for the duration required for the curing operation, e.g. can be in the range of 0.1 to 5% by weight based on the total amount of the resin liquid () and the resin liquid (). The present invention is constructed and used as described above, but the key points are an unsaturated polyester (A), a monomer having an unsaturated group (B), a thermoplastic resin (C), and an aliphatic carboxylic acid (D). A liquid resin composition with a specific surface area of 15,000
By uniformly mixing fine fillers with a particle size of cm ² /g or more, the overall separation stability and storage stability are excellent, and the volume change during curing is small, resulting in high crack prevention. When used together with a reinforcing material such as glass fiber, a strong molded product can be obtained with a relatively small amount of reinforcing material without reducing the volume content of the reinforcing material. The structure and effects of the present invention will be specifically explained below by referring to reference examples, working examples, and comparative examples, but these are not intended to limit the present invention, and may be used as appropriate in keeping with the spirit of the above explanation. Of course, it is also possible to implement with modifications. Note that "parts" in the examples indicate parts by weight unless otherwise specified. Reference Example 1 74 g of phthalic anhydride, 49 g of maleic anhydride, and 80 g of propylene glycol were placed in a four-necked flask equipped with a thermometer, partial condenser, total condenser, inert gas inlet tube, and stirrer, and placed in an inert gas atmosphere. A dehydration condensation reaction was carried out at 200°C to obtain an unsaturated polyester with an acid value of 40. 60 parts of this polyester was mutually dissolved with 0.01 part of hydroquinone and 40 parts of styrene to obtain a resin (). Reference Example 2 40 parts of polystyrene having a molecular weight of 200,000 was dissolved in 60 parts of styrene along with 0.01 part of hydroquinone to obtain a resin (). Examples and Comparative Examples 100 parts of the resin obtained in Reference Example 1, 25 parts of the resin obtained in Reference Example 2, and 1.5 parts of dimer acid were mixed to obtain a liquid unsaturated polyester resin composition.
To 100 parts of this liquid composition, 50 parts of calcium carbonate (filler) having different specific surface areas were added and thoroughly mixed to obtain a uniform resinous composition (Table 1). 0.1 part of cobalt octenoate and tert-butyl peroxyoctoate to 100 parts of this resinous composition.
Add 0.5 parts and mix uniformly as an impregnating agent, and use glass roving as a reinforcing material.
FRP molded products were molded using the flyment winding method. The results of measuring the volume content of the reinforcing material, wall thickness, bending strength, presence of cracks, and presence of color unevenness in the obtained molded products are also listed in Table 1.

[Table] As is clear from the results in Table 1, even when using the same resins (), () and dimer acid, and using the same amount of filler (calcium carbonate), The physical properties of the molded article obtained by the specific surface area of the filler are significantly improved. In other words, when a filler with a specific surface area of 10,800 cm ² /g is used (Comparative Example 2), the volume content of the reinforcing material in the molded product is significantly lower than when the resin is used alone (Comparative Example 1). If ^a reinforcing material of
If fillers of cm ² /g (Example 2) and 21000 cm ² /g (Example 3) are used, excellent molded products can be produced without decreasing volume content, increasing wall thickness, or decreasing strength. Obtainable.

Claims (1)

[Claims] 1 (A) unsaturated polyester, (B) monomer having an unsaturated group, (C) thermoplastic resin compatible with the above monomer, and (D) carbon number per carboxyl group is 2
-25 and the total number of carbon atoms is 3 to 50. For 100 parts by weight of a liquid unsaturated polyester resin composition consisting of an aliphatic carboxylic acid having a total carbon number of 3 to 50, (E) a specific surface area of 15000
A resin composition characterized in that it contains an inorganic or organic fine powder filler of cm ² /g or more in an amount of 10 parts by weight or more.