JPS6031558A - Unsaturated polyester resin composition - Google Patents

Abstract

PURPOSE:To lower the viscosity by incorporating palmitic or stearic acid. CONSTITUTION:An unsaturated polyester resin compsn. contg. palmitic or stearic acid further contains, if necessary, filler, hardener, hardening inhibitor, low shrinking agent, parting agent, thickener, pigment, etc. The viscosity of the compsn, is lowered by incorporating the above acid and the viscosity is lowered with an increase in the quantity of the acid. Pref. these acids are used together in a quantity of 0.5-5wt% based on that of the unsaturated polyester resin. The addition of palmitic and stearic acids in a weight ratio of 4/6-8/2 is particularly effective in lowering the viscosity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is suitable for manufacturing molded articles. The present invention relates to an unsaturated polyester resin composition having a low viscosity.

The viscosity of the unsaturated polyester resin composition influences the manufacturing workability when producing an unsaturated polyester resin molded article, and the suitability of the viscosity can sometimes affect the properties of the resulting molded article. Therefore, in general, depending on the manufacturing method and manufacturing conditions of the molded product,
The viscosity of the unsaturated polyester resin composition is adjusted.

For example, sheet molding compound (SMC) is a typical fiber-reinforced unsaturated polyester resin molding material.
When used as an automobile exterior component, the molded product must be completely free of defects such as small pinholes, corrugations, and uneven gloss, and unsaturated polyester resin compositions and reinforcing fiber materials that cause these defects must be In order to avoid insufficient wetting with the resin, the viscosity of the unsaturated polyester resin composition is adjusted to 500 poise or less. In addition, when manufacturing fiber-reinforced unsaturated polyester resin molded products using the hand lay-up method,
In order to reduce the number of voids contained in the molded product, the viscosity of the unsaturated polyester resin composition is adjusted to several tens of poise or less to facilitate air bubble removal during lamination.

The viscosity rJt of such an unsaturated polyester resin composition
There are many other demands for the 4th adjustment, most of which are demands for a reduction in employment. For this reason, nine different methods of reducing viscosity have been studied and are actually practiced, but they often have side effects such as a decrease in strength and an increase in price, and there are few methods that are satisfactory.

For example, in the method of lowering the viscosity by increasing the amount of ethylenically unsaturated monomer (liquid) in the unsaturated polyester resin composition, the amount of ethylenically unsaturated monomer relative to the unsaturated groups of the unsaturated polyester is large. Too much 1 Mechanical properties deteriorate. There is also a method of lowering the degree of condensation of the unsaturated polyester in the unsaturated polyester resin composition to reduce the molecular weight and completely lowering the viscosity of the unsaturated polyester resin composition.

This reduces the strength of the molded product. In addition, in an unsaturated polyester resin composition containing a filler, the viscosity is lowered by reducing the amount of the filler.

It becomes impossible to maintain the original rigidity and price.

As a method to meet such demands,
There is a method such as that shown in Japanese Patent No. 7834, but a more effective method is desired. The present invention satisfies the above requirements for lower viscosity.

The object of the present invention is to provide an unsaturated polyester resin composition whose viscosity is reduced by a simple method.

The present invention relates to an unsaturated polyester resin composition containing palmitic acid or stearic acid.

The unsaturated polyester resin composition in the present invention includes maleic acid, maleic anhydride, unsaturated dibasic acid such as fumaric acid, phthalic acid, phthalic anhydride, halogenated heptalic anhydride, inphthalic acid as necessary. , terephthalic acid, tetrahydrophthalic anhydride.

Acid components of saturated dibasic acids such as succinic acid and adipic acid, and ethylene glycol and diethylene glycol.

Globilenoglycol, diglopyrene glycol.

1.3 Butanediol, neopentyl glycol.

Hydrogenated bisphenol A, 1,6-hexanediol.

1. Styrene, chlorostyrene and unsaturated polyester obtained by reacting a glycol component such as 4-phundiol, an adduct of bisphenol A and globylenoxide or ethylene oxide.

Divinylbenzene, vinyltrilenine, vinyl acetate.

Alkyl ester of acrylic acid or methacrylic acid.

It contains an unsaturated polyester resin in the form of a mixture with ethylenically unsaturated monomers such as and mixtures thereof. In the present invention, there are no particular limitations on the type or amount of these ethylenically unsaturated monomers.

Generally, one of the unsaturated dibasic acids in the unsaturated polyester
~2.5 times the molar amount is used.

In addition to the unsaturated polyester resin described above, the unsaturated polyester resin composition in the present invention contains a filler, a curing agent, a curing inhibitor, and a low-shrinkage agent, if necessary.

Contains release agents, thickeners, pigments, etc. The types and amounts of these materials are not particularly limited.

Fillers typically include calcium carbonate, aluminum hydrate, barium sulfate, and antimony dioxide.

Powdered fillers such as silicon dioxide, Merck, silica sand, and mixtures thereof can be used.

Further, as a curing agent, t-butyl peroxybenzoate, benzoyl peroxide, t-butyl peroctoate, lauroyl peroxide.

Methyl ethyl ketone peroxide, 1,1-di-t-
Organic peroxides such as butylperoxy (3.3.5-)limethylcyclohexane, azobisin butyronitrile, etc. are used as hardening inhibitors, hydroquinone, parabenzoquinone, etc. are used as low shrinkage agents, and styrene/based resins are used as low shrinkage agents. , thermoplastic resins such as polyester resins, acrylic resins, acetic acid resins, polyethylene resins, and polycaprolactam (thermoplastic resins that have been dissolved in ethylenically unsaturated monomers in advance if necessary) can also be used. As the mold release agent, zinc stearate, calcium stearate, etc. are used. Yet again. Thickeners such as magnesium oxide, calcium oxide, magnesium hydroxide, calcium hydroxide, and various pigments and colorants may also be added.

The unsaturated polyester resin composition of the present invention has a low viscosity by containing palmitic acid or stearic acid. The effect of lowering the viscosity becomes greater as the amount of 7JO added to palmitic acid or stearic acid increases.

The optimum amount to be added can be freely determined depending on the conditions of use of the unsaturated polyester resin composition, but if palmitic acid and stearic acid are used together, the amount should be 0.5 to 5 times the weight of the unsaturated polyester resin. A range is preferred. Also, palmitic acid or stearic acid alone has a viscosity-lowering effect, but especially when the N ratio (a)/(bl of the amount of palmitin 9[al and stearic acid (b) added is 4/6 to 8/2) Palmitic acid, which has a large viscosity-reducing effect, is preferred.In general, industrially produced palmitic acid is preferable.

Although the purity of fatty acids such as stearic acid is not 100%, the above addition amount ratio (al/fb11.i) must be calculated based on the substantial amount of each component.

An example of the present invention will be shown below.

The viscosity of Examples was measured using a Brookfield rotational viscometer.

The unsaturated polyester resins A and B used were synthesized as follows.

1) Unsaturated polyester resin A 0.79 mol of maleic acid, 0.21 mol of phthalic acid.

Charge 0.35 mol of ethylene glycol and 0.65 mol of 113-butanediol into a flask, and add 200 ppm.
of hydroquinone was added. After maintaining the temperature at about 150° C. for about 1 hour while heating and stirring under a nitrogen atmosphere, the temperature was gradually increased and stirring was continued at 200 to 229° C. to obtain an unsaturated polyester with an acid value of 22.

Hydroquinone (200 ppm) and styrene monomer (35%) were added and dissolved to obtain an unsaturated polyester resin.

2) Unsaturated polyester resin B 0.4 mol of maleic acid, 0.6 mol of phthalic acid, 0.6 mol of propylene glycol, and 0.5 mol of ethylene glycol were placed in a flask and synthesized in the same manner as above.

An unsaturated polyester having an acid value of 29 was obtained. To this, 200 pI) m of hydroquinone and styrene monomer were added and dissolved to make 31 m, and unsaturated polyester resin B
I got it.

Table 1 shows the viscosity lowering effect of the unsaturated polyester resin composition for SMC having the formulation shown below. The viscosity of Comparative Example 1, which does not contain palmitic acid and stearic acid, was 752 poise, while Example 1, which contained palmitic acid and stearic acid, had a viscosity of 440 poise, showing a viscosity-lowering effect of 41 units. Furthermore, Examples 2 and 3 show viscosity reductions of 20% and 25 inches, respectively.

Furthermore, as shown in Example 4, the viscosity reduction effect of the unsaturated polyester resin composition for hand lay-up molding was reduced by 23% by the addition of palmitic acid and stearic acid.
8 poise became 6.2 poise.

In addition, in Example 5 and Example 6, 10 and 15 pieces were used, respectively.
shows a decrease in viscosity.

By containing palmitic acid or stearic acid as described above, a low-viscosity unsaturated polyester resin composition that is excellent in workability in manufacturing fiber-reinforced unsaturated polyester resin molded articles can be obtained.

Claims (1)

[Claims] 1. An unsaturated polyester resin composition containing palmitic acid or stearic acid.