JPH0114255B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to an unsaturated polyester curable resin composition.

SMC (plate molding material) and BMC (bulk molding material)
In addition, there are wet molding methods such as the so-called mated die method, and resin injection methods.
Unsaturated polyester curable resin compositions are widely used in RIM methods and the like.

By the way, it is known that unsaturated polyester has a large mold shrinkage during mold curing, and in order to improve the dimensional accuracy of the molded product and to improve other physical properties such as impact resistance, unsaturated polyester is used. It is widely practiced to add other thermoplastic polymer compounds to the polymer. However, if the composition is simply a mixture of the two, the surface of the molded product will be extremely poor, and the degree of reduction in shrinkage and improvement in impact resistance will be very poor. Moreover, since such compositions generally do not have sufficient compatibility or dispersion stability, they are also poor in molding workability.

Therefore, an unsaturated polyester curable resin that has sufficient compatibility or dispersion stability, has good molding workability, and can provide clearly superior physical properties such as surface properties, low shrinkage, and impact resistance to the molded product. The emergence of compositions is strongly required.

The present invention relates to an unsaturated polyester curable resin composition that meets such demands.

<Conventional technology and its problems> Conventionally, a carboxylic acid group is present in the molecule of a polymer compound added to an unsaturated polyester, and the gap between the carboxylic acid group and the terminal free carboxylic acid group of the unsaturated polyester is oxidized. Bonding via an alkaline earth metal oxide such as magnesium or its hydroxide is widely practiced. In this case, if the polymer compound added is a copolymer of methacrylic acid or acrylic acid and methyl methacrylate, vinyl acetate, styrene, etc., a partial effect can be observed. However, compositions produced by this type of means are far from being able to improve the physical properties of the molded products as described above.

On the other hand, for the purpose of improving the impact resistance etc. of molded products,
It is also possible to target a diene polymer as the polymer compound to be added and use it by the same conventional means as above, but the surface of the molded product obtained from such a composition will have significant gloss spots and other problems. The various physical properties of the diene polymer are also poor, and the presence of carboxylic acid groups in the diene polymer has no effect. The diene polymer itself having a carboxylic acid group is dissolved in the styrene monomer, which is a monomer component used in the unsaturated polyester curable resin composition, but when α,β-ethylenically unsaturated polyester, etc. When they coexist, they separate into layers very quickly. Diene-based polymers having carboxylic acid groups have too poor compatibility or dispersibility with unsaturated polyesters, and even when something like magnesium oxide is added to them,
Through this, there is a considerable amount of separation between the two before they form a salt-forming bond, and this is presumed to be the reason why the physical properties of molded products obtained from such compositions are not improved in the end.

Therefore, compositions containing block copolymers of styrene polymers have been proposed in the past to improve the compatibility or dispersibility with unsaturated polyesters (JP-A-53-74592, JP-A-60
-99158), although the compatibility and dispersibility have been improved to some extent, the molded product obtained from this composition uses a block copolymer with a styrenic polymer skeleton that essentially has poor toughness. It is significantly inferior in terms of low shrinkage and especially impact resistance.

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

As a result of intensive research from the above viewpoint, the present inventors have found that it is correct and preferable to use an unsaturated polyester containing a specific block copolymer that shares a polyester segment and a polydiene segment as a block. They discovered this and completed the present invention.

That is, the present invention provides a block copolymer in which one or more polyester segments are ester bonded to one polydiene segment, the polydiene segment having a number average molecular weight of 1000 to 5000, and the polyester segment having a number average molecular weight of 1000 to 5000. The segment is one or more organic dicarboxylic anhydrides selected from saturated aliphatic dicarboxylic anhydrides, saturated alicyclic dicarboxylic anhydrides, and aromatic dicarboxylic anhydrides, and 1,2-
The present invention relates to an unsaturated polyester curable resin composition characterized by containing both a block copolymer formed by condensation formation of epoxides and an unsaturated polyester.

In the present invention, the block copolymer is produced using a modified polydiene having one or more hydroxyl or carboxylic acid groups in the molecule as a starting material, and a predetermined organic dicarboxylic anhydride and 1,2- By alternately reacting with epoxides and condensing polyester chains via the hydroxyl or carboxylic acid groups of the modified polydiene, it can be obtained stably and industrially advantageously.

The important point of the block copolymer of the present invention is that it has a structure in which one or more polyester segments are bonded to one polydiene segment. There are no particular limitations on the bonding positions of the polyester segments in the combination. The hydroxyl group or carboxylic acid group of the modified polydiene to which the polyester segment is bonded may be in the chain or at the end of the modified polydiene. Furthermore, the polydiene constituting the segment does not suffer from stereoisomerism or structural isomerism due to differences in polymerization methods such as radical polymerization, ionic polymerization, living polymerization, etc.

Monomeric diene compounds constituting the polydiene segment include butadiene, isoprene, chloroprene, 1,3-pentadiene, etc., but examples of polydienes having hydroxyl or carboxylic acid groups that can be advantageously used in the present invention include: ,α,ω−
1,2-Polybutadiene glycol (Nisso PB
-G series, number average molecular weight 1000-3000), α,
ω-1,2-polybutadiene dicarboxylic acid (Nisso PB-C series, number average molecular weight 1000~
3000), α,ω-1,2-polybutadiene-terminated maleic acid half ester (Nisso PB-GM series,
Number average molecular weight 1000-3000, the above three items are manufactured by Nippon Soda Co., Ltd.), terminal carboxyl-modified 1,4-polybutadiene (Hycar CTB series, number average molecular weight 3500)
~4800, manufactured by Ube Industries or BF Gutsudoritsu), terminal hydroxyl group-modified 1,4-polybutadiene (Poly-bd R-45M, number average molecular weight 2500, or
Examples include Poly-bd R-45HT, number average molecular weight 4000, manufactured by Idemitsu Petrochemical Co., Ltd. or Arco Chemical Co., Ltd.).

In the present invention, organic dicarboxylic anhydrides include saturated aliphatic dicarboxylic anhydrides such as succinic anhydride, aromatic dicarboxylic anhydrides such as phthalic anhydride and naphthalic anhydride, and cyclohexanedicarboxylic anhydride. and saturated alicyclic dicarboxylic acid anhydrides such as endomethylene cyclohexane dicarboxylic anhydride.

In the present invention, examples of the 1,2-epoxide include ethylene oxide, propylene oxide, and 1,2-butylene oxide.

Furthermore, the catalysts used in producing the block copolymer of the present invention include lithium halides such as lithium chloride and lithium bromide, tetramethylammonium bromide, tributylmethylammonium bromide, and tetrapropylammonium chloride. Alkyl quaternary ammonium salts are mentioned.

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

The basic idea of the present invention is to use a block copolymer in which polyester is bonded to polydiene as a segment in order to improve compatibility or dispersibility with unsaturated polyester while utilizing the inherent properties of polydiene. It is in.

In the above block copolymer, the content of the polyester segment can be appropriately selected in relation to the content of the unsaturated polyester used together. Generally, polyester segments include poly(propylene glycol phthalate),
Poly(ethylene glycol phthalate/succinate), poly(butylene glycol succinate)
It has good compatibility and dispersibility with a wide variety of unsaturated polyesters.

Tests regarding compatibility and dispersibility with unsaturated polyester will be described later, but even if the compatibility and dispersibility between unsaturated polyester and block copolymer are somewhat insufficient, it is possible to acid groups, preferably 50 mol% or more of the terminal groups are carboxylic acid groups,
By adding magnesium oxide or magnesium hydroxide as a thickener, sufficient compatibility or dispersibility can be obtained. The content of polyester segments in the block copolymer also affects the compatibility and dispersibility with the unsaturated polyester. Generally, increasing the content of polyester segments increases compatibility or dispersibility, and conversely, decreasing the content decreases compatibility or dispersibility.

When the main purpose of coexisting a block copolymer with an unsaturated polyester is to improve the impact resistance and surface properties of a molded product, the polydiene segment in the block copolymer may be a polybutadiene segment. is preferable; in this case,
The polyester segment content in the block copolymer is made as low as possible while taking into consideration compatibility and dispersibility with the unsaturated polyester. In addition, when the main purpose is to improve the hot strength of the molded product, that is, to reduce the temperature dependence of the bending and tensile strength of the molded product, and to maintain the surface properties of the molded product, it is possible to improve the hot strength of the molded product. It is preferable to make the polyester segment content slightly higher.

The number average molecular weight of the polydiene segment in the block copolymer used in the composition according to the present invention is 1000.
~5000, preferably 1000-3000,
Generally, the content of polyester segments in the block copolymer is preferably 10 to 60% by weight.

In the present invention, the block copolymer is usually 25 to
It is common to use a 40% by weight solution of a polymerizable monomer, such as styrene monomer, and to mix 20 to 50% by weight of the solution with respect to the unsaturated polyester. However, depending on the type of block copolymer, it is not necessary to dissolve it in a polymerizable monomer such as styrene monomer before adding it to the unsaturated polyester; The monomer may be added and then the block copolymer may be added thereto.

The unsaturated polyester that can be advantageously used in the composition of the present invention is a condensed polyester of α,β-ethylenically unsaturated dicarboxylic acid and glycols, or a condensed polyester containing a conjugated diene compound in an unsaturated group. In addition to the added modified unsaturated polyesters, there are novolak type unsaturated polyesters and vinyl ester type unsaturated polyesters, but the present invention does not impose any restrictions on the content of the unsaturated polyesters. The solvents contained in these unsaturated polyesters include polymerizable monomers such as styrene, methacrylic acid ester, and diallyl phthalate, but styrene is usually used and the solid content is adjusted to 60 to 65% by weight. Things are easy to use.

As explained above, the solvent in the composition according to the present invention is usually a styrene monomer, but in order to impart flame retardance to the molded article, a part or all of it can be a chlorostyrene monomer. Furthermore, in order to improve the weather resistance and gloss of the molded product, methyl methacrylate may be used as part of the styrene monomer. In addition, various polymerizable monomers may be present in the composition depending on the purpose.

The simplest composition of the composition according to the invention is, as mentioned above, a mixture of a block copolymer and an unsaturated polyester. The molding method is Matsushido die method.
In the case of resin press-in method (RIM method), hand lay-up method, filament winding method, etc.
The simplest composition is used by adding trace amounts of additives such as curing catalysts and mold release agents as appropriate.
At this time, a conventionally known polymer compound may be added if necessary. For premix molding materials such as SMC and BMC, fillers such as calcium carbonate, if necessary, thickeners such as alkaline earth metal oxides, hydroxides, or diisocyanates, and reinforcing agents such as glass fiber, etc., are used as a molding guide. Although various substances are added depending on the composition, the mixing ratio and mixing method are not particularly different from those of conventionally known compositions.

Hereinafter, in order to make the present invention more specific, reference examples and examples for producing block copolymers will be given.
The present invention is not limited to these examples.

<Examples, etc.> Production Reference Example 1 Phthalic anhydride 52.3g (0.35 mol), succinic anhydride 82.5g (0.825 mol), lithium chloride 0.7g and α,ω-1,2-polybutadiene glycol (NissoPB) as a catalyst. −G1000, number average molecular weight
1430, manufactured by Nippon Soda Co., Ltd.) was charged into an autoclave, the reaction system was purged with nitrogen gas, and then heated to 130° C. with stirring. Then,
42.7 g (0.74 mol) of propylene oxide was press-injected over 1 hour. Aging at 130℃ for 2 hours,
When the reaction is completed, a pale yellow transparent viscous product 890
I got g. The molecular weight of the polybutadiene-polyester block copolymer obtained here was 1786 (calculated value), the proportion of polyester segments was 20.0% by weight, the acid value was 27, the hydroxyl value was 38, and the end groups of the polyester segments were 41.5 mol%. was a carboxylic acid group.

Production reference example 2 Block copolymer 800 obtained in production reference example 1
g (0.448 mol) and 54.2 g (0.54 mol) of succinic anhydride
mol) was charged into a flask and reacted for 2 hours at a temperature of 120 to 125°C in a nitrogen stream. After the contents were cooled to 50° C., 214 g of styrene monomer was added to prepare a styrene solution containing 80% by weight of the block copolymer. The styrene solution containing this block copolymer had an acid value of 50.7 and a hydroxyl value of 1.9, and 96.4 mol% of the terminal groups of the polyester segments were carboxylic acid groups.

Example 1 A 33% by weight styrene solution of the two block copolymers obtained in Production Reference Examples 1 and 2 was prepared. 40 parts by weight of each solution and 60 parts by weight of the following unsaturated polyesters were mixed and compatibility and dispersibility were tested.
The unsaturated polyesters used were U-Pica 7507 (manufactured by Japan U-Pica), Polyset 9120, Polyset 9107,
There are five types: Polyset 2212 and Polyset 6200 (the above four items are manufactured by Hitachi Chemical). Approximately 10% phase separation was observed in 24 hours only in the case of the combination of block copolymer and Polyset 9107 in Production Reference Example 2, but phase separation was observed in all other combinations even without a thickener. I couldn't help it.

Therefore, it was expected that all of the above combinations of compositions would give beautiful molded products with uniform surface gloss by various molding methods.

Therefore, for each of the two types of block copolymers,
For 40 parts by weight of 33% styrene solution,
Prepare a solution containing 60 parts by weight of 7507, 1.5 parts by weight of tertiary butyl perbenzoate and 3.0 parts by weight of zinc stearate in a Banbury mixer, and add
After adding 200 parts by weight of calcium carbonate powder and making it well homogeneous, 60 parts by weight of 1/2 inch long glass fibers were added, and after 1 minute, the Banbury mixer was stopped to prepare a premix. This premix was based on the composition of the present invention, and when it was molded at a mold temperature of 145°C, molded products with uniform surface gloss were obtained. The molding shrinkage rate was 0.004% when the block copolymer of Sanzo Reference Example 1 was used, and 0.005% when the block copolymer of Production Reference Example 2 was used. ) was 17.0 foot-pounds/inch when the block copolymer of Production Reference Example 1 was used, and 17.4 foot-pounds/inch when the block copolymer of Production Reference Example 2 was used.

On the other hand, instead of a block copolymer, α, ω
A premix made under the same conditions except for using -1,2-polybutadiene glycol (as described in Production Reference Example 1) is known, but the surface of the molded product has significant gloss spots and Izotsu impact strength (with notch) is 11.8 ft.
It was in pounds per inch.

Example 2 Polylite PC- as an unsaturated polyester was added to 500 parts by weight of a 33% by weight styrene solution of the two block copolymers obtained in Production Reference Examples 1 and 2.
Add 500 parts by weight of 670 (manufactured by Dainippon Ink Co., Ltd.) and further dissolve 60 parts by weight of cobalt naphthenate to obtain a viscosity of 830.
Centipoise of liquid was obtained. When this liquid is fed into a resin injection mold (commonly known as RIM or RTM) in which a glass mat has been set in advance, acetylacetone peroxide is mixed in at a concentration of 1% by weight with respect to the fed liquid. It was pumped into the mold. At that time, the liquid receiving port of the mold had a diameter of 20 mm, and the mold temperature at the time of feeding was 25°C. After 2 hours, the mold temperature began to rise due to polymerization heat, and reached a maximum temperature of 70°C within 3 hours. After a further 3 hours had passed, the mold was opened and the molded product was taken out. The appearance of the molded product was uniform and there were no particular gloss spots, and compared to a molded product obtained without using the block copolymer but with all other things being the same, the surface was smoother and there was almost no visible protrusion of glass fibers. Nakatsuta.

<Effects of the Invention> As is clear from each example, the present invention described above has sufficient compatibility or dispersion stability,
The molding workability is good, and the molded product has the advantage of being able to have excellent physical properties improved in terms of surface properties, low shrinkage, and impact resistance.

Claims (1)

[Claims] 1. A block copolymer in which one or more polyester segments are ester bonded to one polydiene segment, and the polydiene segment has a number average molecular weight of 1000 to 5000,
The polyester segment contains one or more organic dicarboxylic anhydrides selected from saturated aliphatic dicarboxylic anhydrides, saturated alicyclic dicarboxylic anhydrides, and aromatic dicarboxylic anhydrides;
- An unsaturated polyester curable resin composition characterized by containing both a block copolymer obtained by alternately condensing epoxides and an unsaturated polyester. 2. The unsaturated polyester curable resin composition for SMC or BMC as set forth in claim 1, further comprising a polymerizable monomer, a filler, a curing catalyst, a mold release agent, and a reinforcing fiber. 3. The unsaturated polyester curable resin composition according to claim 1 or 2, which further contains a thickener. 4. The unsaturated polyester curable resin composition according to any one of claims 1 to 3, wherein the organic dicarboxylic anhydride is succinic anhydride and/or phthalic anhydride. 5. In any one of claims 1 to 4, the 1,2-epoxide is one or more selected from ethylene oxide, propylene oxide, and butylene oxide. Saturated polyester curable resin composition. 6. The unsaturated polyester curable resin composition according to any one of claims 1 to 5, wherein 50 mol% or more of the terminal groups of the polyester segments are carboxylic acid groups. 7. An unsaturated polyester curable resin composition as set forth in claim 6, wherein the carboxylic acid group is obtained by reacting a terminal hydroxyl group of a polyester segment with succinic anhydride and/or phthalic anhydride. thing. 8. In the statement of any one of claims 1 to 7, 10 in the block copolymer
An unsaturated polyester curable resin composition in which ~60% by weight is polyester segments. 9. In the statement of any one of claims 1 to 8, the unsaturated polyester is selected from α,β-ethylenically unsaturated polyester, novolak type unsaturated polyester, and vinyl ester type unsaturated polyester. type 1 or 2
An unsaturated polyester curable resin composition that is more than a species.