JPH0148926B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides styrene-fumaric acid ester and/or
Alternatively, the present invention relates to an unsaturated polyester resin molding composition containing a styrene-maleate copolymer. More specifically, the product contains a styrene-fumarate ester and/or maleate ester copolymer, shows almost no curing shrinkage at any curing temperature, has good storage stability before curing, and exhibits no layer separation after curing. The present invention relates to an unsaturated polyester resin molding composition that does not exhibit.

In recent years, unsaturated polyester resins have been used as raw materials for glass-reinforced plastics using sheet molding compound (SMC) molding methods, bulk molding compound (BMC) molding methods, etc., and as raw materials for resin concrete using silica sand as aggregate.
Furthermore, it has been used as a raw material for casting.

However, unsaturated polyester resin shrinks in volume by 5 to 12% when cured, so molded products made from it have a lot of distortion and are prone to cracking, and they also have a tendency to shrink when reinforcing glass fibers and aggregates. The disadvantage was that peeling was likely to occur at the interface.

Conventionally, in order to compensate for these drawbacks, a low-shrinkage agent was mixed with a so-called highly reactive unsaturated polyester resin containing many α,β-unsaturated dibasic acid residues, and the resin was heat-cured to reduce shrinkage during curing. Measures have been taken to eliminate it. Known low-shrinkage agents used for this purpose include polystyrene, polypropylene, polymethyl methacrylate, polyvinyl acetate, their copolymers, and saturated polyesters. Preferred polystyrene was common. However, unsaturated polyester resin molding compositions using polystyrene as a low-shrinkage agent still have insufficient compatibility, causing layer separation within at least two weeks, and are prone to bleeding during or after molding, resulting in mechanical damage to the molded product. It also had the disadvantage of poor toughness.

As a result of intensive research in order to improve these drawbacks, the present inventor has developed styrene-
By mixing fumaric acid and/or styrene-maleate ester copolymer, it is possible to obtain a molded product that has excellent compatibility and toughness and hardly shrinks during curing. Vinyl polymerizable monomer (B) having a group or an epoxy group
The present inventors have discovered that a molded product that does not bleed can be obtained by incorporating a vinyl monomer having an epoxy group, and have completed the present invention.

That is, the present invention provides (A) unsaturated polyester
100 parts by weight (abbreviated as parts below) (B) Vinyl polymerizable monomer 5 to 200 parts (C) Styrene-fumarate ester copolymer, styrene-maleate ester copolymer,
5 to 200 parts of an unsaturated polyester resin molding composition, more preferably the vinyl polymerizable monomer (B) contains a vinyl polymerizable monomer having an epoxy group. or the styrene
Fumarate copolymer and/or styrene
The maleate ester copolymer (C) has vinyl groups and/or
Alternatively, the present invention provides an unsaturated polyester resin molding composition having an epoxy group.

In the present invention, component (A) unsaturated polyester includes, for example, α,β-ethylenically unsaturated dibasic acids such as maleic anhydride, fumaric acid, citraconic acid, and itaconic acid, ethylene glycol, propylene glycol, It refers to products obtained by condensation reaction with polyhydric alcohols such as 4-butanediol and 1,6-hexanediol and/or alkylene oxide as essential components.

The vinyl monomer of component (B) is, for example, styrene,
Examples include vinyl toluene, diallyl phthalate, (meth)acrylates, and preferably vinyl monomers having an epoxy group, such as glycidyl (meth)acrylate and allyl glycidyl ether. The amount of the vinyl monomer (B) used is 5 to 200 parts, preferably 20 parts to 100 parts of unsaturated polyester.
-100 parts; if it is less than 5 parts, the viscosity of the composition will be high and molding workability will be poor; if it is more than 200 parts, molding shrinkage will be large and it will be impractical. Furthermore, when a vinyl monomer containing an epoxy group is used, the bleedability during and after molding is improved, and the adhesion to the reinforcing material is improved.

The styrene-fumarate ester copolymer and styrene-maleate ester copolymer of component (C) are:
Styrene and fumaric acid and/or maleic acid (anhydride) may be radically copolymerized and esterified with alcohols or epoxy group-containing compounds, or styrene and fumaric acid or maleic acid esters may be copolymerized. good.

What is an ester of fumaric acid or maleic acid?
each monoester or diester,
Used in one or more of them. Alcohols include methyl alcohol, ethyl alcohol,
Examples include monohydric alcohols such as propyl alcohol, butyl alcohol, and 2-ethylhexyl alcohol. Examples of the epoxy group-containing compound include ethylene oxide, propylene oxide, monoepoxide of versatile acid ester, and the like.

Examples of mono- and/or diesters of fumaric acid include monoalkyl fumaric esters and dialkyl fumaric esters, such as monomethyl fumaric ester, dimethyl fumaric ester, dibutyl fumaric ester, and 2-fumaric acid.
Examples include ethylhexyl ester, fumaric acid-β-hydroxyethyl monoester, fumaric acid-β-hydroxyethyl-butyl ester. Examples of maleic acid mono- and/or diesters include maleic acid monoalkyl esters and maleic acid dialkyl esters, such as maleic acid monomethyl ester, maleic acid dimethyl ester, maleic acid dibutyl ester, maleic acid-2-ethylhexyl ester, maleic acid- Examples include β-hydroxyethyl monoester.

The copolymer (C) contains, in addition to styrene, fumarate ester and/or maleate ester, monomers that can be copolymerized with these monomers, such as alkyl (meth)acrylate, vinyl acetate, α
- Copolymerizing methylstyrene, etc. is a
It is acceptable as long as it does not reduce the compatibility with the β-ethylenically unsaturated polyester (A). The copolymer (C) can also be obtained by solution polymerization, suspension polymerization, or emulsion polymerization and removing the medium, but since the copolymer has a low viscosity and a small reaction heat during formation, It has the advantage of being economical because it can be bulk polymerized. To introduce a vinyl group into a styrene-fumarate ester and/or styrene-maleate ester copolymer, it is easy to add a vinyl monomer having an epoxy group, such as glycidyl methacrylate, to the remaining carboxyl group. . In addition, in order to introduce an epoxy group into the styrene-fumarate ester and/or styrene-maleate ester copolymer, a vinyl monomer having an epoxy group, such as methyl glycidyl methacrylate, is added to the styrene and fumarate ester and/or styrene-maleate ester copolymer. It is easy to copolymerize with maleic acid ester.

In this molding composition, the amount of the copolymer (C) used is 5 to 200 parts per 100 parts of unsaturated polyester.
Preferably, the amount is 10 to 50 parts; if it is less than 5 parts, the shrinkage rate of the molded product will be large, and if it is more than 200 parts, the heat resistance will be poor.
Poor solvent resistance and impractical.

The composition of the present invention shows almost no curing shrinkage at any curing temperature, has good storage stability before curing, and is an excellent molding material that does not cause layer separation after molding.

Examples are given below and will be explained more specifically.
The present invention is not limited thereby.
Note that parts in the formulations in the text and examples indicate weight.

Reference Example 1 (Synthesis of styrene-fumaric acid ester copolymer) 232 g of fumaric acid, 520 g of 2-ethylhexanol, and 0.2 g of zinc acetate were charged into a reaction vessel equipped with a condenser, a thermometer, a nitrogen gas inlet tube, and a stirrer. Gradually heated and dehydrated in a nitrogen gas stream,
The temperature was raised to .degree. C. and condensation was further carried out for 8 hours to obtain 650 g of a mixture (a) containing 90% by weight of fumaric acid diester and 10% by weight of fumaric acid monoester. In a reaction vessel similar to the above, 550 g of mixture (a) and 10 g of benzoyl peroxide.
350g of styrene at 80℃ in a nitrogen gas stream.
was added dropwise and polymerized for 8 hours, and then 5 g of benzoyl peroxide was added to form a very viscous styrene.
A fumaric acid ester copolymer (b) was obtained. Copolymer (b)
1000g of styrene after adding 0.1g of hydroquinone to
Thinned with 2 g of dimethylbenzylamine,
Add 100 g of glycidyl methacrylate and carry out an addition reaction at 80°C to an acid value of 5 to obtain a styrene solution of vinyl group-containing styrene-fumaric acid ester copolymer (c).
I got it.

Reference Example 2 (Production of unsaturated polyester resin (e)) 6 mol of phthalic anhydride, 4 mol of maleic anhydride,
10.5 mol of 1,2-propylene glycol was reacted in a nitrogen gas stream at 170°C to 210°C by a conventional method to obtain unsaturated polyester (d) having an acid value of 33. 600 parts of this unsaturated polyester (d) was dissolved in 400 parts of styrene monomer to which 0.1 part of hydroquinone was added to obtain an unsaturated polyester resin (e).

Reference Example 3 (Production of unsaturated polyester resin (H)) 3.6 moles of phthalic anhydride, 6.4 moles of maleic anhydride, and 11 moles of propylene glycol were reacted in the same manner as in Reference Example 2 to produce an unsaturated polyester (H) with an acid value of 30. Obtained. 700 parts of this unsaturated polyester (f) was dissolved in 300 parts of styrene and 0.1 part of hydroquinone to obtain an unsaturated polyester resin (f).

Example 1 60 parts of unsaturated polyester (d) was added to a styrene solution of a vinyl group-containing styrene-fumaric acid ester copolymer.
(c) Dissolved in 80 parts. This composition was allowed to stand for one month, but no phase separation occurred. 6 to 140 parts of this composition
% cobalt octate, 1.0 part of methyl ethyl ketone peroxide, 200 parts of No. 5 silica sand, 50 parts of heavy calcium carbonate, glass fiber with a length of about 6 mm.
Kneaded 12 parts. Pour this mixture into the formwork,
After standing for 30 minutes, a molded product was obtained. This molded product was molded according to the mold, and there were no cracks or delaminations.
The molding shrinkage rate was as small as 0.05%.

The molding shrinkage rate is determined by the following formula.

Molding shrinkage rate (%) = Formwork inner diameter dimension - Molded product outer diameter dimension / Formwork inner diameter dimension ×
100 Example 2 1000 parts of unsaturated polyester resin (T), styrene
Dibutyl fumarate copolymer (copolymerization weight ratio 65:
35) were mixed with 200 parts of the styrene solution (80% non-volatile content). This mixed composition did not separate even after being left for one month. 1200 parts of this mixed composition, 2000 parts of calcium carbonate, 30 parts of ter-butyl perbenzoate,
Add and mix 50 parts of zinc stearate and 10 parts of magnesium oxide, impregnate 1,200 parts of glass fiber (length 2.4 cm) with a squeezing roll, coat it, cover both sides with polyethylene film, mature at 40℃, and form SMC.
I got it. This SMC was press-molded at 140° C. and 80 kg/cm ² for 3 minutes to obtain a molded product with a shrinkage rate of 0.3%.

Example 3 1000 parts of unsaturated polyester resin (T), styrene
160 parts of fumaric acid ester copolymer (b), 10 parts of glycidyl methacrylate, 30 parts of styrene, 2000 parts of calcium carbonate, 50 parts of zinc stearate, 0.03 parts of ter-butylcatechol, 30 parts of ter-butyl perbenzoate, and magnesium oxide. 10 parts of the mixture was added and mixed, and 1200 parts of glass fiber (length 2.4 cm) was impregnated with a squeezing roll, coated, both sides were covered with polyethylene film, and aged at 40°C to obtain SMC. This SMC was press-molded at 140° C. and 80 kg/cm ² for 3 minutes to obtain a molded product with good smoothness and no bleeding during molding. The molding shrinkage rate was 0.3%.

Claims (1)

[Claims] 1 (A) 100 parts by weight of unsaturated polyester (B) 5 to 200 parts by weight of vinyl polymerizable monomer (C) Styrene-fumaric acid ester copolymer and/or
or styrene-maleate ester copolymer
An unsaturated polyester resin molding composition comprising 5 to 200 parts by weight. 2. The molding composition according to claim 1, wherein the vinyl polymerizable monomer (B) contains a vinyl polymerizable monomer having an epoxy group. 3 Styrene-fumaric acid ester copolymer and/or
The molding composition according to claim 1 or 2, wherein the styrene-maleate copolymer (C) has a vinyl group and/or an epoxy group.