JPS5947710B2 - Unsaturated polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an unsaturated polyester resin composition that has good moldability and rigidity and forms molded articles with excellent impact resistance.

In general, unsaturated polyester resin is a typical thermosetting resin that is used in a wide range of fields due to its good physical properties and good moldability, but its application is limited due to its insufficient impact resistance. It is inevitable that there will be restrictions on the field.

In order to improve the impact resistance of unsaturated polyester resin,
Plasticization is carried out by adding saturated polyester or modifying acids or alcohols with long alkyl chains as one component, but although this method improves impact resistance, it does not improve bending strength. etc., the rigidity is significantly impaired.

It is also possible to add polybutadiene rubber as a component for the purpose of improving impact resistance, but this method has poor compatibility and may cause the premix to separate into upper and lower layers in a short period of time, or increase It becomes viscous, significantly impairing molding workability, and even if a molded product can be formed, the appearance is impaired and the reinforcing effect is low. Various other methods have been proposed for the purpose of improving impact resistance, but although they may improve impact resistance, they significantly reduce some of the excellent performance originally possessed by unsaturated polyester resins. This results in damage and has little practical value. As a result of intensive research aimed at improving the impact resistance without impairing the excellent properties originally possessed by unsaturated polyester resins, the present inventors found that acrylic resins with polymerizable unsaturated groups in their premixes It was discovered that by adding an acid ester polymer as one component, molding workability is good, the resulting molded product has excellent impact resistance, and furthermore, bending strength etc. are improved, and the present invention has been achieved. I've reached it. 20 to 80 parts by weight of the unsaturated polyester of the present invention (hereinafter referred to as
B) Vinyl having 20 to 80 parts of a vinyl monomer and an unsaturated group active in O polymerization, and containing no acrylic acid alkyl ester having 1 to 4 carbon atoms in an alkyl group and no other functional group. 80 to 100% by weight of the former in total with monomers
and the latter 0-20 weight? An object of the present invention is to provide an unsaturated polyester resin composition comprising an acrylic acid alkyl ester polymer (hereinafter simply referred to as an unsaturated acrylic polymer) containing the following.

The composition of the present invention has good molding workability, and the molded product obtained by molding has excellent impact strength, and surprisingly, not only impact strength but also rigidity such as bending strength is excellent at the same time. It is something that can be obtained.

Furthermore, the molded product thus obtained has an extremely excellent appearance. Although the theoretical details behind the recognition of such excellent characteristics are not clear,
It can be thought of as follows. Generally, when different types of polymers are mixed with unsaturated polyester and low molecular weight vinyl monomer, due to poor compatibility, they may separate into upper and lower layers immediately or within a relatively short time, or the miscibility may be poor. A very high shearing force is required for mixing, and the viscosity of the system obtained in this way is too high, which significantly reduces molding workability. A certain unsaturated acrylic polymer has moderate compatibility with the other two components of the present invention, so in the system of the present invention, separation of the upper and lower layers does not occur over time, and the miscibility is good and the system It is thought that the viscosity is also relatively low, and therefore a product with good molding workability can be obtained.

In addition, when a catalyst or a catalyst and an accelerator are added and the curing reaction is allowed to proceed by heating or standing at room temperature, the unsaturated acrylic polymer that is one component of the present invention can be obtained from the other two components of the present invention. Due to its moderate incompatibility with the hard unsaturated polyester resin continuous phase, microscopic phase separation occurs and the unsaturated acrylic polymer becomes dispersed in the form of fine particles. The polymerization-active unsaturated groups react with the unsaturated polyester and vinyl monomer to form a solid bond with the hard unsaturated polyester resin continuous phase. It is believed that the impact energy is transmitted to the acrylic polymer particles dispersed in the acrylic polymer particles, and the impact energy is absorbed by the acrylic polymer particles, resulting in the unsaturated polyester resin obtained in the present invention having excellent impact strength. Furthermore, because of this morphology, what imparts bending strength is a hard unsaturated polyester resin continuous phase, and despite the addition of a soft material (acrylic polymer), the bending strength does not decrease; rather, the soft material It is thought that it exhibits a stronger crosslinked structure due to the unsaturated groups that have polymerization activity and improves bending strength and bending absorption energy. Furthermore, as expected from this configuration, the appearance of the molded product obtained by the present invention is good. This morphology is also supported by microscopic observation results. (See Figure 1)
As described above, for the composition of the present invention, appropriate compatibility before curing and appropriate incompatibility after curing are essential conditions for the effects of the present invention, and therefore, the acrylic polymer, which is one of the components of the present invention, is essential for achieving the effects of the present invention. Coalescence should be within the scope of the composition of the present invention.

In addition, it is an essential condition that the fine particles are strongly bonded to the continuous phase, and in order to satisfy this condition, the acrylic polymer must not only contain polymerization-active unsaturated groups but also other essential components. It should also contain a polymerization-active unsaturated group.
Furthermore, in order to improve the impact strength without reducing the inherent bending strength of the unsaturated polyester resin, the composition of the present invention must contain A) 20 to 80 parts of unsaturated polyester, and B) 20 to 20 parts of vinyl monomer. 80 parts, C) unsaturated acrylic polymer 3
It is also an essential condition that the composition be composed of 30 parts of the ingredients. In addition, if the unsaturated polyester exceeds 80 parts (
(If the vinyl monomer content is small), the viscosity of the composition becomes high, resulting in poor workability, and the molded product becomes susceptible to hydrolysis.

If the amount of the polyester is less than 20 parts (if the vinyl monomer is large), the curing speed of the composition will be slow and the rigidity of the molded product will be reduced, which is not preferable. If the amount of the unsaturated acrylic polymer is less than 3 parts, the effect of impact resistance of the molded product cannot be improved, and if it exceeds 30 parts, the improvement in impact resistance reaches a plateau, and the bending strength and modulus of elasticity decrease. This is not preferable because the decrease becomes significant. The unsaturated polyester used in the present invention is obtained by dehydration condensation from an unsaturated dicarboxylic acid or a mixture of an unsaturated dicarboxylic acid and a saturated dicarboxylic acid and a polyhydric alcohol.

Examples of unsaturated dicarboxylic acids include maleic acid, fumaric acid,
Examples include itaconic acid, citraconic acid, and anhydrides thereof. Examples of saturated dicarboxylic acids include adipic acid, succinic acid, phthalic acid, isophthalic acid, terephthalic acid, and anhydrides thereof. Further examples include halogen-substituted derivatives of the above dicarboxylic acids. Polyhydric alcohols include ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, butanediol, hexane diol, neopentyl glycol, hydrogenated bisphenol A) ethylene oxide and propylene oxide adducts of bisphenol, epoxidized products of bisphenol , glycerin, pentaerythol, etc. Furthermore, halogen-substituted products of these, such as glycerin monochlorohydrin, are also included. The vinyl monomers used in the present invention are usually those used for unsaturated polyesters and have a low molecular weight, such as styrene, α-methylstyrene, vinylbenzenes such as vinyltoluene, acrylic acid and its esters, Methacrylic acid and its esters, aliphatic unsaturated nitriles such as acrylonitrile and methacrylonitrile, allyl compounds such as allyl methacrylate, diallyl phthalate and triallyl cyanurate, vinyl carboxylates such as vinyl acetate and vinyl propionate, Examples include vinyl halides such as dicarostyrene and phosphorus-containing compounds such as diallylbenzenephosphonate.

In the unsaturated acrylic polymer used in the present invention, the former 8 in the total of the acrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms and the vinyl monomer containing no other functional groups.
It is a polymer consisting of 0 to 100% by weight and 0 to 20% by weight of the latter, and has a polymerization-active unsaturated group at the terminal or side chain of the polymer.

Specific examples of acrylic acid alkyl esters having an alkyl group having 1 to 4 carbon atoms include methyl acrylate, ethyl acrylate, butyl acrylate, and mixtures of two or more thereof. Vinyl monomers that do not contain other functional groups (hereinafter referred to as other copolymerizable vinyl monomers) are copolymerizable with acrylic acid alkyl esters and have functional groups other than vinyl groups. Specific examples include vinylbenzenes, aliphatic unsaturated nitriles, other acrylic esters, methacrylic esters, vinyl carboxylates, and mixtures of two or more of these. can give. The weight ratio of acrylic acid alkyl ester having an alkyl group of 1 to 4 carbon atoms and other copolymerizable vinyl monomer is 80 to 100/20-0. The molecular weight of the acrylic polymer obtained from the above monomer is:
Although there is no particular limitation, 500 to 200,000 is generally preferred.

Although any method may be used to introduce the polymerization-active unsaturated group into the acrylic polymer, the following method is preferably used.

(c) A vinyl monomer having a hydroxyl group, such as hydroxyethyl acrylate, hydroxyethyl methacrylate, etc., is copolymerized with the monomers forming the unsaturated acrylic polymer to form an acrylic acid ester-based polymer containing a hydroxyl group; A diisocyanate and an acrylic ester or methacrylic ester having a hydroxyl group are reacted sequentially or simultaneously, or an unsaturated isocyanate having both one polymerizable unsaturated group and one free isocyanate group in the molecule. A method of introducing a polymerizably active unsaturated group through a urethane bond by reacting the
No. 31).

2) A vinyl monomer containing a carboxyl group, such as acrylic acid or methacrylic acid, is copolymerized with the monomers forming the unsaturated acrylic polymer to form an acrylic acid ester polymer containing a carboxyl group. , a method of reacting glycidyl acrylate or glycidyl methacrylate or monoepoxy esters of difunctional epoxy compounds with methacrylic acid or acrylic acid, etc., to introduce polymerizably active unsaturated groups through ester bonds (Japanese Patent Publication No. 47 -31432).

3) Glycidyl acrylate or glycidyl methacrylate is copolymerized with monomers forming the above-mentioned unsaturated acrylic polymer to obtain an acrylic acid ester polymer containing glycidyl groups. A method of introducing a polymerizably active unsaturated group by reacting an unsaturated carboxylic acid (Japanese Patent Publication No. 48-4444).

4) Copolymerizing a vinyl monomer having a hydroxyl group with the monomers forming the unsaturated acrylic polymer to obtain an acrylic acid ester polymer having a hydroxyl group, and reacting this with maleic anhydride. This is a method in which a half ester of maleic acid is reacted to introduce a polymerizable unsaturated group (Japanese Patent Publication Nos. 46-26867 and 46-18133).

5) When polymerizing the monomers forming the unsaturated acrylic polymer, a polymerization initiator containing a hydroxyl group or a carboxyl group, such as δ,δ1-azobis-δ-cyanovaleric acid, δ,δ7-azobis-1, is used. By using δ-cyano-n-pentanol, an acrylic acid ester polymer having a hydroxyl group or a carboxyl group at the end can be obtained, and by utilizing the reactivity of the functional group at the end, products such as those described in items 1) to 4) can be obtained. A method of introducing a polymerization-active unsaturated group via an ester bond or a urethane bond.

6) When polymerizing the monomers forming the unsaturated acrylic polymer, an organic mercaptan containing a hydroxyl group or a carboxyl group, such as mercaptoethanol, mercaptopropionic acid, etc., is used to form a monomer that has a hydroxyl group or a carboxyl group at the end. By using an acrylic ester polymer and utilizing the reactivity of the terminal functional group, 1) ~
4) A method of introducing a polymerization-active unsaturated group via an ester bond or a urethane bond.

Further, the number of polymerization-active unsaturated groups contained in the unsaturated acrylic polymer may be substantially one or more in one molecule. The unsaturated polyester resin composition according to the present invention can be cured using a conventional catalyst or a catalyst and an accelerator under heat or at room temperature.

Moreover, various fillers, colorants, and flame retardants can be added as necessary. Furthermore, it is also effective to make the plastic reinforced with glass fiber. The unsaturated polyester resin composition according to the present invention and the composition to which various additives are added as necessary can be made into desired molded products by various casting methods, lamination molding methods, etc.

Next, examples will be shown.

Example 1 (1) Synthesis of unsaturated polyester resin solution A mixture consisting of 1 mole of phthalic anhydride, 1 mole of maleic anhydride, and 2 moles of propylene glycol was reacted at a temperature of 200 to 210°C until the acid value reached 30 or less. An unsaturated polyester was synthesized.

The unsaturated polyester was dissolved in styrene monomer, and 40% of hydroquinone and 30% of t-butylcatechol were added.
[PI]l was added to synthesize an unsaturated polyester resin solution (A-1) with a nonvolatile content concentration of 66%.

The viscosity at 25°C was 8.5 poise.

(2) Synthesis of unsaturated acrylic polymer A mixture of 95 parts of ethyl acrylate, 5 parts of methacrylic acid, and 3 parts of azobisisobutyronitrile was added to a mixed solvent of 25 parts of xylol and 25 parts of butyl acetate.
Polymerization was carried out by dropwise addition at 00° C. over a period of 2 hours (a).

In a separate reaction vessel, 180 parts (1 equivalent) of Epicote 828 (product of Ciel Chemical Co., Ltd.) and 30 parts (0.35 parts) of methacrylic acid were added.
equivalent) 0.1 part of hydroquinone, 0.1 part of tributylamine.
3 parts, 45 parts of xylene and 45 parts of butyl acetate to 100 parts
The reaction was carried out at ℃ until the acid value became 1 or less (b).

150 parts of (a), 5 parts of (b), and 0.3 parts of tributylamine were mixed and reacted at 100°C until the acid value was constant. The solvent was distilled off under reduced pressure to form an unsaturated acrylic polymer. (B-1) was obtained.

(3) Production of unsaturated polyester resin A premix prepared by mixing 100 parts of (A-1) and 5 parts of (B-1) had a viscosity of 8.6 poise at 25°C.

Even after several weeks, no increase in viscosity or separation of the upper and lower layers was observed. Next, 6% naphthenic acid, 0.1 part of cobalt, and 1 part of methyl ethyl ketone peroxide were mixed, poured into a casting plate, cured at room temperature, and then after-cured at 90°C for 4 hours to form a 3m71L thick surface with good condition. A plate-like material was obtained. Table 1 shows the physical properties. Comparative Example 1 A 3 mm thick plate was molded in the same manner as in Example 1 (3) using only the unsaturated polyester resin solution (A-1) of Example 1.

Table 1 shows the physical properties. Example 2 A plate-like product with a good appearance was obtained by molding in the same manner as in Example 1 except that the amount of unsaturated acrylic polymer (B-1) added was increased to 10 parts.

The viscosity of the mixture before molding was 10.5 poise at 25°C. Table 1 shows the physical properties. A microscopic photograph (×400) of the obtained molded product was taken and shown in FIG.

According to FIG. 1, the unsaturated acrylic polymer is dispersed in a substantially spherical shape. The fineness and uniformity of these dispersed particles is thought to be the main reason for maintaining the beautiful appearance of the molded product, and the fact that the fine and uniformly dispersed particles are thought to be firmly bonded to the continuous phase improves strength. It is thought that it is forcing them. Example 3 Molding was carried out in the same manner as in Example 1 except that the amount of unsaturated acrylic polymer (B-1) added was increased to 15 parts.

A plate-like product with good appearance was obtained. Table 1 shows the physical properties. Example 4 An unsaturated polymer obtained by substituting 1/2 of the ethyl acrylate in (2) of Example 1 with butyl acrylate in place of the unsaturated acrylic polymer (B-1) in Example 1 Molding was carried out in the same manner as in Example 1 except for using the acrylic polymer (B-2).

A plate-like product with good appearance was obtained. Table 1 shows the physical properties. Example 5 An unsaturated acrylic polymer (B-1) obtained by substituting ethyl acrylate in (2) of Example 1 with butyl acrylate in place of the unsaturated acrylic polymer (B-1) in Example 1 B-3
) was molded in the same manner as in Example 1 except for using the following.

A plate-like product with good appearance was obtained. Table 1 shows the physical properties. Example 6 An unsaturated acrylic polymer (B-4) obtained by replacing 5% of butyl acrylate with acrylonitrile in the synthesis of the unsaturated acrylic polymer (B-3) in Example 5 was used. Molding was carried out in the same manner as in Example 5 except for the use.

A plate-like product with good appearance was obtained. Table 1 shows the physical properties. Comparative Example 2 A mixture of 100 parts of ethyl acrylate and 3 parts of azobisisobutyronitrile was added dropwise to a mixed solvent of 25 parts of xylol and 25 parts of butyl acetate at 100°C over 2 hours to polymerize. After that, the solvent was distilled off under reduced pressure to obtain an acrylic polymer (B'-
Molding was carried out in the same manner as in Example 3 except that 1) was used.

Table 1 shows the physical properties. Comparative Example 3 The ethyl acrylate in (2) of Example 1 was converted to acrylic acid 2-
Unsaturated acrylic polymer (B'
-2) was obtained.

Molding was carried out in the same manner as in Example 3 except that the unsaturated acrylic polymer (B'-2) was used instead of the unsaturated acrylic polymer (B-1).

A plate with low gloss was obtained. Table 1 shows the physical properties. Comparative Example 4 100 parts of unsaturated polyester resin solution (A-1) and a butadiene polymer containing a polymerization-active vinyl group (1
, 2-polybutadiene (molecular weight approximately 3,000) was mixed, resulting in high viscosity and a tendency to separate into upper and lower layers in a short period of time.

0.1 part of 6% cobalt naphthenate and 1 part of methyl ethyl ketone peroxide were added, quickly mixed, poured into a casting plate, and cured, but only a non-uniform molded product was obtained.

Example 7 (1) Synthesis of unsaturated polyester resin solution 1 mole of hydrogenated bisphenol A, 1 mole of propylene glycol
200 moles of maleic anhydride and 2 moles of maleic anhydride.
An unsaturated polyester was synthesized by reacting at ~210°C until the acid value reached 30 or less.

The unsaturated polyester was dissolved in styrene monomer, and 40 ppm of hydroquinone and 3 t-butylcatechol were added.
An unsaturated polyester resin solution (A-2) with a nonvolatile content concentration of 66% was synthesized by adding 0 pp[n.

The viscosity at 25°C was 8.2 poise.

(2) Synthesis of unsaturated acrylic polymer 33 parts of ethyl acrylate and 1 part of 2-mercaptoethanol
．． 73 parts were charged into a reaction vessel, stirred and heated to raise the temperature to 130°C, and then, at 110°C, 67 parts of ethyl acrylate and 3.47 parts of 2-mercaptoethanol were added from separate dropping devices over a period of 2 hours. The mixture was then held for an additional 2 hours for polymerization, and a small amount of volatile matter was distilled off under reduced pressure to obtain a polymer having a hydroxyl value of 36 and a hydroxyl group at the end.

100 parts of the polymer having a hydroxyl group at the end and 11.1 parts of tolylene diisocyanate (0H/NCO equivalent ratio 1/2)
was charged and reacted at 70°C for 4 hours to obtain a polymer with terminal isocyanate. Next, 10.2 parts of β-hydroxyethyl acrylate (0H/NCO equivalent ratio 1.5/1),
0.012 parts of tin octylate and 0.0 part of hydroquinone
A mixture consisting of 12 parts was added and reacted at 70°C for 16 hours to obtain a terminally unsaturated acrylic polymer (B-5).
(3) Production of unsaturated polyester resin 100 parts of (A-2) and 5 parts of (B-5) were mixed.

The solution had a low viscosity and was easy to handle, and no separation of the upper and lower layers occurred even when it was left standing. Add to this 6% cobalt naphthenate 0.1
and 1 part of methyl ethyl ketone peroxide,
It was poured into a casting board and allowed to harden at room temperature.

After-curing was then carried out at 90° C. for 4 hours. 37 with good appearance! A plate-like product having a thickness of m was obtained. Table 1 shows the physical properties. Example 8 (1) Synthesis of unsaturated polyester resin solution A mixture consisting of 1 mole of isophthalic acid, 1 mole of maleic anhydride and 2 moles of propylene glycol was reacted at 200 to 210°C until the acid value reached 30 or less to produce an unsaturated polyester. I got it.

The unsaturated polyester was dissolved in methyl methacrylate monomer, and 40 parts of hydroquinone and 30 parts of t-butylcatechol were further added to obtain an unsaturated polyester resin solution (A-3) with a nonvolatile content concentration of 66%.

The viscosity at 25°C was 8.1 poise.

(2) Synthesis of unsaturated acrylic polymer In (2) of Example 7, 100 parts of ethyl acrylate was replaced with 95 parts of ethyl acrylate and 5 parts of methyl methacrylate. ) An unsaturated acrylic polymer (B-6) was obtained.

(3) Production of unsaturated polyester resin Molding was carried out in the same manner as in Example 7 except that 100 parts of (A-3) and 5 parts of (B-6) were used.

A plate-like product with a good appearance was obtained. Table 1 shows the physical properties. Example 9 A flat plate (300 x 30
0U1L x 31m) was molded.

Claims (1)

[Claims] 1 A) 20 to 80 parts by weight of unsaturated polyester, B) 20 to 80 parts by weight of vinyl monomer, and C) acrylic acid alkyl ester having a polymerization-active unsaturated group and an alkyl group having 1 to 4 carbon atoms. In the total sum of vinyl monomers containing no other functional groups, the former is 80 to 100% by weight and the latter is 0 to 100% by weight.
An unsaturated polyester resin composition comprising 3 to 30 parts by weight of an acrylic acid alkyl ester polymer containing 20% by weight.