JP2551540B2 - Unsaturated polyester curable resin composition - Google Patents

Description

The present invention relates to an unsaturated polyester curable resin composition.

Fiber reinforced plastic (FRP) using unsaturated polyester resin has excellent strength, heat resistance, water resistance, chemical resistance, and high productivity, and is widely used in bathtubs, water tank panels, wash bowls, etc. There is. In recent years, unsaturated polyester-based sheet molding compounds (SM
C) and bulk molding compound (BMC) have been spotlighted as plastic materials for automobile exterior panels, and are used as main exterior panels such as engine hoods, roofs and trunk lids, as well as exterior parts such as spoilers, air intakes, and rocker panels. ing.

By the way, it is known that the thermosetting unsaturated polyester resin has a large shrinkage at the time of curing. Therefore, a molded article obtained from the thermosetting unsaturated polyester resin is apt to cause cracks and warps, and is used for reinforcement. The surface appearance and paintability are impaired due to the emergence of glass fibers and the occurrence of pinholes (porosity), and the dimensional stability is also poor.

The present invention relates to an unsaturated polyester curable resin composition capable of improving such drawbacks.

<Conventional technology and its problems> Conventionally, in order to make up for the above-mentioned drawbacks, a block copolymer of polystyrene, polyvinyl acetate, polymethylmethacrylate, a conjugated diene compound and an aromatic vinyl compound is added to an unsaturated polyester resin. (29th National SAMPE Symp
osium April 3-5, 1984) and the like are mixed as a shrinkage reducing agent.

However, these thermoplastic resins have compatibility or dispersibility when mixed with an unsaturated polyester resin, low shrinkage ability,
The fact is that there is nothing that comprehensively satisfies the surface smoothness of the molded product, and therefore it is merely used by making the best use of some of its properties. Particularly, for a molding material used as an outer panel of an automobile, a surface quality equivalent to that of a steel sheet is required as a property thereof, and therefore, an unsaturated polyester resin composition using the above-mentioned known thermoplastic resin as a shrinkage reducing agent is used. In the case of products, there is a problem that the required quality cannot be satisfied at all.

<Problems to be Solved by the Invention and Means for Solving the Problems> The present invention provides a new unsaturated polyester curable resin composition that solves the above-mentioned conventional problems.

However, the inventors of the present invention have earnestly studied a molding material having characteristics such as excellent surface smoothness and paintability which are particularly required as an outer panel of an automobile. As a result, the thermosetting unsaturated polyester resin has a polyisoprene segment. And a composition containing a specific block copolymer that shares a polyester segment with excellent mechanical strength, heat resistance, water resistance,
It has been found that in addition to chemical resistance, it has surface smoothness and paintability required for application to automobile outer panels.

That is, the present invention is obtained by alternately reacting an organic dicarboxylic acid anhydride and a 1,2-epoxide in the presence of a catalyst with a polyisoprene compound having a hydroxyl group or a carboxyl group in the molecule and having a viscosity average molecular weight of 10,000 or more. In the block copolymer, a polyester segment formed from the organic dicarboxylic acid anhydride and the 1,2-epoxide via an ester bond to one polyisoprene segment formed from the polyisoprene compound is The unsaturated polyester curable resin composition is characterized by containing a block copolymer having two or more bonded thereto, an unsaturated polyester, an olefinic unsaturated monomer, a filler, a curing catalyst and a reinforcing fiber.

In the present invention, the block copolymer is prepared by using a polyisoprene compound having a hydroxyl group or a carboxyl group in the molecule and having a viscosity average molecular weight of 10,000 or more as a starting material, and adding an organic dicarboxylic acid anhydride and 1,2 in the presence of a catalyst. Obtained by alternating reaction with epoxide. For more details,
The block copolymer of the present invention uses a hydroxyl group or a carboxyl group present in the molecule of the polyisoprene compound as a starting substrate, and an organic dicarboxylic acid anhydride and 1,2-epoxide are alternately present in the presence of a catalyst. In the reaction, a polyisoprene segment formed from the polyisoprene-based compound is bound to a polyester segment condensed from the organic dicarboxylic acid anhydride and the 1,2-epoxide via an ester bond, Two or more polyester segments are bonded to one polyisoprene segment through an ester bond.

The essential point in the block copolymer of the present invention is that one polyisoprene segment and two or more polyester segments formed by condensation with an organic dicarboxylic acid anhydride 1,2-epoxide are shared, and both are used as segments. However, the present invention does not particularly limit other structures of the block copolymer. For example, the hydroxyl group or carboxyl group present in the polyisoprene compound may be in the chain of the polyisoprene compound or may be less than the chain, or may be directly linked to the chain or through any atomic group. May be indirectly connected. In addition, the polyiprene-based compound that will form the segment is
Stereoisomerism and structural isomerism due to different polymerization methods such as radical polymerization, ionic polymerization, and living polymerization do not pose a problem.

Examples of the polyisoprene-based compound that can be advantageously used in the present invention include Claprene LIR-503 (hydroxyl group-modified polyisoprene, viscosity average molecular weight 25000, hydroxyl group number 2.5 / molecule), Claprene LIR-506 (hydroxyl group-modified polyisoprene, viscosity average). Molecular weight 25,000, number of hydroxyl groups 5.9 / molecule, Claprene LIR-403 (carboxyl modified polyisoprene,
Viscosity average molecular weight 25,000, carboxyl group number 3 / molecule), Klaprene LIR-410 (carboxyl modified polyisoprene, viscosity average molecular weight 25000, carboxyl group number 10 / molecule, the above four points are manufactured by Kuraray Co., Ltd.) and the like.

Examples of the organic dicarboxylic acid anhydride that can be used in the present invention include succinic acid anhydride, maleic acid anhydride, aliphatic dicarboxylic acid anhydride such as alkenylsuccinic acid anhydride, phthalic acid anhydride, and naphthalenedicarboxylic acid anhydride. Aromatic dicarboxylic acid anhydrides, cyclohexanedicarboxylic acid anhydrides, cyclohexene dicarboxylic acid anhydrides, aliphatic dicarboxylic acid anhydrides such as endomethylene cyclohexene dicarboxylic acid anhydride, and the like, but among these, succinic anhydride, phthalic acid Acid anhydrides are preferred.

Further, as the 1,2-epoxide that can be used in the present invention,
Examples thereof include ethylene oxide, propylene oxide, and 1,2-butylene oxide.

And as a catalyst that can be used when alternately reacting the organic dicarboxylic acid anhydride and the 1,2-epoxide as exemplified in the present invention, lithium halides such as lithium chloride and lithium bromide, tetramethylammonium bromide. , Tetraalkyl quaternary ammonium salts such as totibutylmethyl ammonium bromide and tetrapropyl ammonium chloride.

Needless to say, the present invention is not limited to any of the above examples.

The basic idea of the present invention is to improve the surface quality of the obtained molded product by controlling the compatibility or dispersibility with the thermosetting unsaturated polyester resin while utilizing the intrinsic properties of the polyisoprene compound. Therefore, a block copolymer in which a polyester segment is bonded to the isoprene-based compound is used.

In the above block copolymer, the content of the polyester segment can be appropriately selected in relation to the content of the thermosetting unsaturated polyester resin used together.
Generally, as the polyester segment, poly (propylene glycol phthalate), poly (propylene glycol phthalate succinate), poly (butylene glycol succinate), etc. are relatively wide and suitable for various thermosetting unsaturated polyester resins. Good. In some cases, it is also effective to allow an unsaturated group based on α, β-ethylenically unsaturated dicarboxylic acid to be present in the polyester segment.

The terminal group of the polyester segment in the block copolymer used in the present invention is usually a hydroxyl group or a carboxyl group or a mixture thereof, but SMC such as adding magnesium oxide or magnesium hydroxide as a thickener.
Alternatively, in the case of BMC compositions, those in which 50% or more of the terminal groups of the polyester segment are carboxyl groups are extremely effective in improving the stability of these compositions and the physical properties of the resulting molded articles.

The content of the polyester segment in the block copolymer also affects the compatibility or dispersibility with the thermosetting unsaturated polyester resin. Generally, if the content of the polyester segment is increased, the compatibility or dispersibility is increased,
On the contrary, if it is lowered, the compatibility or dispersibility is reduced.

As described above, the main object of the present invention is to improve the surface characteristics of the obtained molded product, and in order to achieve the object, a polyisoprene compound that forms a polyisoprene segment in a block copolymer is used. Has a viscosity average molecular weight of 10,000 or more.
It is preferable to use one having 20,000 to 50,000, and the polyisoprene compound having two or more hydroxyl groups or carboxyl groups in the molecule is used, but one having 2.5 to 10 on average, particularly 2.5 to 6 on average. It is preferable to use the one having a number. In this case, the polyisoprene segment content in the block copolymer is preferably as high as possible in consideration of compatibility or dispersibility with the thermosetting unsaturated polyester resin.

Generally, the polyisoprene segment content in the block copolymer used in the composition according to the present invention is 95-40% by weight.
Is preferable, and 90 to 70% by weight is more preferable.

In the present invention, the block copolymer is usually a solution of 25 to 40% of an olefinic unsaturated monomer such as a styrene monomer, and 20 to 50% of the solution is mixed with a thermosetting unsaturated polyester resin. It is usually used. However, depending on the type of block copolymer, it is not necessary to dissolve it in an olefinic unsaturated monomer such as a styrene monomer before adding it to the thermosetting unsaturated polyester resin. A predetermined amount of olefinic unsaturated monomer may be added to the resin, and the block copolymer may be added thereto.

The unsaturated polyester used in the present invention is synthesized by condensing an α, β-olefinic unsaturated dicarboxylic acid and a divalent glycol. Saturated dicarboxylic acid or aromatic dicarboxylic acid may be supplementarily used as the dibasic carboxylic acid. Further, dicyclopentadiene or the like which reacts with carboxylic acid may be used in combination with glycol. As the α, β-olefinic unsaturated dicarboxylic acid, maleic acid, fumaric acid,
Examples thereof include itaconic acid, citraconic acid and anhydrides of these dicarboxylic acids. Examples of the auxiliary dicarboxylic acid include adipic acid, sebacic acid, succinic acid, glutanoic acid, phthalic anhydride, o-phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid and tetrachlorophthalic acid. .

As the divalent glycol, alkanediol, oxaalkanediol, diol obtained by adding ethylene oxide or propylene oxide to bisphenol A, and the like are used. In addition, monool or triol may be used supplementarily. The alkane diols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6 -Hexanediol, cyclohexanediol, etc. are mentioned. Examples of the oxaalkane diol include dioxyethylene glycol and totioxyethylene glycol. Examples of auxiliary monools and triols include octyl alcohol, oleyl alcohol, and trimethylolpropane.

The synthesis of unsaturated polyester is generally carried out under heating, and the reaction proceeds while removing by-product water, but the average molecular weight is usually 800 to 4000 and the acid value is 20 to 60.

Examples of the olefinic unsaturated monomer used in the present invention include styrene, p-chlorostyrene, vinyltoluene,
Esters of divinylbenzene, acrylic acid or methacrylic acid with alcohols having 1 to 18 carbon atoms, for example,
Examples thereof include methyl methacrylate, butyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, and totimethylol propane trimethacrylate.

Examples of the filler used in the present invention include calcium carbonate, talc, silica, clay, glass powder and glass balloons.

The curing catalyst used in the present invention is not particularly limited as long as it decomposes at 80 to 200 ° C. to generate radicals and initiates the polymerization of unsaturated polyesters and olefinic unsaturated monomers. Is t-butylperoxyoctoate, t-butylperoxybenzoate,
1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, t-butylperoxy 2-ethylhexyl carbonate, dicumyl peroxide and the like can be mentioned.

Examples of the auxiliary fiber used in the present invention include glass fiber, carbon fiber, polyamide fiber, vinylon fiber, polyester fiber, boron fiber and the like.

If necessary, titanium oxide, carbon black,
Rouge, pigments such as phthalocyanine blue, release agents such as zinc stearate and calcium stearate, thickening agents such as magnesium oxide, magnesium hydroxide, calcium oxide and calcium hydroxide, curing accelerators, curing retarders, You may add a heat resistance stabilizer, a weather resistance stabilizer, etc.

Hereinafter, in order to make the present invention more specific, production examples of block copolymers, examples, and the like will be described.

<Example> ・ Production Reference Example 1 (corresponding to F in Table 1) Carboxyl-modified polyisoprene having a viscosity average molecular weight of 25,000 (Klaprene LIR-403, average of 3 COOH groups / molecule, manufactured by Kuraray Co., Ltd., actual acid value 8.3) 480g, phthalic anhydride 148g (1
Mol), xylene 300 g, and lithium chloride 0.5 g as a catalyst were charged in an autoclave, the reaction system was purged with nitrogen gas, and then heated to 140 ° C. with stirring. Then, 61 g (1.05 mol) of propylene oxide was injected under pressure at 140 ° C. over 1 hour. Aging was carried out at this temperature for 3 hours to complete the reaction, and dexylene was performed to obtain 684 g of a light brown transparent liquid product. The polyisoprene-polyester block copolymer obtained here has a polyisoprene segment ratio of 70% by weight, an acid value of 1.6 and a hydroxyl value.
It was 4.3.

-Production Reference Example 2 (example in which the polyester portion is modified with a terminal carboxyl group, corresponding to E in Table 1) 300 g of the block copolymer obtained in Production Reference Example 1, 2.1 g of succinic anhydride, and 120 g of xylene were added to a Dimroth condenser, thermometer,
The flask was equipped with a stirrer and heated to 140 ° C while stirring under a nitrogen stream. After aging at this temperature for 2 hours to complete the reaction, dexylene was carried out to obtain a light brown transparent liquid product. The polyisoprene-polyester block copolymer obtained here has a polyisoprene segment ratio of 69.5% by weight and an acid value of 4.
7, the hydroxyl value was 1.1.

Block copolymers A to D shown in Table 1 were obtained in the same manner as in Production Reference Examples 1 and 2. As is clear from Table 1, all of the block copolymers A to D are the same as those of E, which have been subjected to terminal carboxyl modification.

For comparison, block copolymers G and H not according to the present invention were synthesized according to Production Reference Examples 1 and 2. The contents are shown in Table 2.

-Examples 1 to 6, Comparative Examples 1 and 2 Block copolymers A to F shown in Table 1 and block copolymers G and H not shown in Table 2 not according to the present invention were used to make a third group. An SMC having the composition shown in the table was prepared.

The unsaturated polyester X was synthesized from 0.8 mol of maleic anhydride, 0.2 mol of isophthalic acid and 1.0 mol of propylene glycol, and contained 40% by weight of styrene and had an acid value of
The viscosities at 18.0 and 25 ° C were 1210 cps. Obtained S
A molded plate was obtained from MC under the following conditions.

Mold temperature 145 ℃ SMC charge rate 40% Pressure 100Kg / cm ² Pressurization time 180 seconds Molded plate dimensions 500 × 1000 × 2mm (wall thickness 2mm) Obtained molded plate on lines 1 to 4 shown in FIG. The surface smoothness was measured. 1mm for each line
The surface of 300 points was measured at a pitch, and the fifth-order regression line calculated from these points and the average deviation (μ) of each measurement point were obtained. The average value of the average deviation of each of the lines 1 to 4 was used as a measure of the surface smoothness. Table 4 shows the surface smoothness of the SMC molded plate containing each block copolymer. From the results shown in Table 4, it is clear that the molded plates obtained from the composition of the present invention all have good surface smoothness.

-Examples 7-10, Comparative Examples 3 and 4 SMCs were prepared using the block copolymers A, B, D and E and the block copolymers G and H for comparison, with the compositions shown in Table 5.

Unsaturated polyester Y is propylene glycol 0.7 mol, dicyclopentadiene 0.3 mol, maleic anhydride 1.0
Synthesized from mol, containing 35% by weight of styrene, having an acid value of 21.0 and a viscosity at 25 ° C. of 950 cps. Got
A molded plate was prepared from SMC by the same method as in Example 1, and the surface smoothness was measured. Further, a two-component acrylic urethane primer was applied to the molded plate, cured at 120 ° C. for 30 minutes, and the adhesiveness was examined by a goose stitch test. The results are shown in Table 6. From the results in Table 6 as well, it is clear that all the molded plates obtained from the composition of the present invention have good surface smoothness and paintability.

<Effect of the Invention> <Effects of the Invention> As is apparent, in the present invention described above, a molded product obtained from the unsaturated polyester curable resin composition is provided with excellent physical property improvements in terms of surface smoothness and paintability. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a plan view showing a line for measuring surface smoothness of a molded plate obtained from the composition of the present invention. 1-4 ... Line

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisayuki Iwai 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Kenichi Nishino 3-13-67 Shimohozumi, Ibaraki City, Osaka Prefecture (72) Inventor Mitsugu Aoki 311-6 Ryofukuji, Kashiba-cho, Kitakatsuragi-gun, Nara Prefecture (72) Inventor Mitsuo Kinoshita 8 (5) No. 8 Nishihama, Mitsu-cho, Takai-gun, Aichi (72) Inventor Tatsuhiko Ozaki 6 Eiraku-cho, Nishio-shi, Aichi No. 74 (56) Reference JP-A-58-206616 (JP, A) JP-A-55-135120 (JP, A) JP-A-54-137090 (JP, A)

Claims (6)

(57) [Claims] 1. A polyisoprene compound having a hydroxyl group or a carboxyl group in the molecule and having a viscosity average molecular weight of 10,000 or more is obtained by alternately reacting an organic dicarboxylic acid anhydride and a 1,2-epoxide in the presence of a catalyst. In the block copolymer, a polyester segment formed from the organic dicarboxylic acid anhydride and the 1,2-epoxide via an ester bond to one polyisoprene segment formed from the polyisoprene compound is An unsaturated polyester curable resin composition comprising a block copolymer in which two or more are bonded, an unsaturated polyester, an olefinic unsaturated monomer, a filler, a curing catalyst and a reinforcing fiber. 2. The unsaturated polyester curable resin composition according to claim 1, wherein the organic dicarboxylic acid anhydride is succinic acid anhydride and / or phthalic acid anhydride. 3. The 1,2-epoxide is ethylene oxide,
Claims 1 or 2 selected from propylene oxide and 1,2-butylene oxide.
Item 2. The unsaturated polyester curable resin composition according to Item 2. 4. A polyester segment in which 50% or more of the terminal groups are carboxyl groups.
The unsaturated polyester curable resin composition according to any one of items. 5. A modified polyisoprene having a viscosity average molecular weight of 20,000 to 50,000 and having an average of 2.5 to 10 hydroxyl groups or carboxyl groups in the molecule, wherein the polyisoprene compound is a modified polyisoprene compound. The unsaturated polyester curable resin composition according to any one of items. 6. The unsaturated polyester curable resin composition according to any one of claims 1 to 5, wherein 95 to 40% by weight of the block copolymer is a polyisoprene segment.