JPS6144949A - Unsaturated polyester resin composition having high thixotropy index - Google Patents

Abstract

PURPOSE:The titled resin composition which has a high thixotropy index and is suitable for use in molding of FRP, made by adding an organocopper salt to an unsaturated polyester resin containing a crosslinking agent and a polymerization initiator incorporated therein. CONSTITUTION:An acid component (a) consisting of a saturated dicarboxylic acid (e.g. phthalic anhydride) and an unsaturated dicarboxylic acid (e.g. maleic anhydride) (the molar fraction of the unsaturated dicarboxylic acid being 0.5- 0.8), and a polyhydric alcohol (b) (e.g. propylene glycol) in the proportion to give the OH/COOH (molar ratio) of 1.1-1.2 are allowed to undergo condensation through hydration to form an unsaturated polyester (A), to which 25-50wt% crosslinking agent (B) (e.g. styrene) and a polymerization initiator (C) are added. 10-50ppm (on a metal basis) organocopper salt (D) (e.g. copper naphthenate) is then incorporated into the obtained unsaturated polyester resin.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an unsaturated polyester resin composition with a large thixotropy.

BACKGROUND OF THE INVENTION Unsaturated polyester resins are widely used in reinforced plastics for bathtubs, toilet bowls, tanks, ships, corrugated plates, flat plates, etc., electrical parts, decorative panels, paints, etc.

In general, unsaturated polyester resins are made into compositions by adding various reinforcing agents, fillers, colorants, mold release agents, curing agents, stabilizers, etc., such as brimix, bulk molding compounds, sheet molding compounds, etc. It is used as a molding material.

Problems to be Solved by the Invention Particularly when unsaturated polyester is used for lamination, a so-called sagging problem generally occurs when forming vertical surfaces, and it is necessary to modify the unsaturated polyester itself or select additives. Efforts are being made to give rice and wheat characteristics as much as possible. In particular, when large-scale molding such as a septic tank is to be carried out, a high thixotropy is required by adding a rice-grain property imparting agent. For example, when the content of a crosslinking agent such as styrene is increased in order to prevent sagging, the adhesion and peel strength for secondary bonding decreases, so fixing with bolts, etc. Extra work will be required. No effective proposal has yet been made regarding a method for firmly adhering molded articles made of unsaturated polyester resin without employing such means.

``::::: ya::M*-46,., 8, conducted research and completed the present invention.

That is, the unsaturated polyester resin composition with a large thixotropy of the present invention has a molar fraction of unsaturated dicarboxylic acid in the acid component of 0.5 to 0.8, and an OH/COOH molar ratio of 1.1. ←←Mo, an unsaturated polyester resin obtained by adding 25 to 50% by weight of a crosslinking agent and a polymerization initiator to an unsaturated polyester of ~1.2, based on the metal purity based on the polyester resin. 10~50p
pm organic copper salt and other fillers as necessary.
It is made by blending reinforcing materials and additives.

The unsaturated polyester used in the present invention is obtained by polycondensing a mixture of an unsaturated dicarboxylic acid and a saturated dicarboxylic acid with a substantially stoichiometric amount of a polyhydric alcohol.

Among the acid components used in the production of unsaturated polyester,
Examples of unsaturated dicarboxylic acids used include unsaturated aliphatic dicarboxylic acids such as fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, and citraconic acid. Maleic anhydride is used.

In addition, examples of saturated dicarboxylic acids include phthalic anhydride, isophthalic acid, terephthalic acid, methylterephthalic acid,
Aromatic dicarboxylic acids such as methyl isophthalic acid, naphthalene dicarboxylic acid, etc.; aliphatic dicarboxylic acids such as adipic acid, sebacic acid, etc.; or tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, tetrabromo phthalic anhydride. Acid, het acid, etc. are used.

Polyhydric alcohols include usually dihydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, cyclopylene glycol, 1,3-butanediol, neopentylene gellicol, hydrogenated bisphenol A1, cyclohexane dimetatool, cyclohexanediol, and bisphenol. A/propylene oxide adduct, bisphenol A/ethylene oxide adduct, etc. are used.

The mole fraction of the unsaturated dicarboxylic acid in the above-mentioned unsaturated dicarboxylic acids and saturated dicarboxylic acids is in the range of 0.5 to 0.8, and generally speaking, the lower the mole fraction of the unsaturated dicarboxylic acid, the softer it becomes. A hard molded product is obtained. In this case, if the molar fraction is less than 0.5, hardness will be caused by Jupiter, and 0.
．． If it is 8 or more, the adhesion of the molded product to the glass will decrease.

On the other hand, C of unsaturated dicarboxylic acid and saturated dicarboxylic acid
The molar ratio of the OH group of the polyhydric alcohol to the 0OH group is 1
．． It ranges from 1 to 12. Usually, the amount of polyhydric alcohol is often used in excess in the range of 1.05 to 1.1 depending on losses in the unsaturated polyester manufacturing process and the target molecular weight of the unsaturated polyester. However, in the present invention, especially 1.1 or more, preferably 1,12 to 1.
If this value exceeds 1.2, the molecular weight will be too small, leading to a decline in the performance of the molded product.

In order to produce an unsaturated polyester by condensing the above-mentioned unsaturated dicarboxylic acid, etc. and a polyhydric alcohol, a normal condensation method is used, for example, mixing a predetermined amount of an unsaturated dicarboxylic acid and a polyhydric alcohol, and then heating the mixture in an inert atmosphere. A method of dehydration condensation at a temperature of about 200° C. can be used.

In the present invention, the thixotropy was measured using a B-type viscometer.
It is determined as the ratio of the viscosity at 6 rpm to the viscosity at 6 rpm. In the present invention, in the case of a large molded product having a thixotropic degree of 3 to 7, a thixotropic degree of 4 to 6 is preferable.

In carrying out the present invention, vinyl monomers are usually used as crosslinking agents for unsaturated polyesters. Specific examples of vinyl monomers include styrene, chlorstyrene, dichlorostyrene, α-methylstyrene, vinylnaphthalene, diallyl phthalate, diallyl maleate, diallyl succinate, ethyl vinyl ether, methyl vinyl ketone, methyl methacrylate, and methyl acrylate. ,
Monomers that do not contain polar functional groups such as ethyl acrylate, acrylonitrile, and methacrylonitrile can be mentioned, and these can be used alone or in a mixed state.

In the present invention, the amount of crosslinking agent is 25 to 50% by weight, preferably 30 to 45% by weight, based on the unsaturated polyester.
used. Therefore, in order to impart properties to the molding process and to keep the viscosity within a suitable range, if this value is less than 25% by weight, the viscosity will become high, which is unsuitable.On the other hand, if it exceeds 50% by weight, it will be difficult to bond with glass. Sexuality decreases.

The organic copper salts used in the present invention include copper naphthenate,
Examples include copper octenoate and other copper salts, and one or more of these organic metal salts may be used. The organic copper salt used in the present invention is used in an amount of 10 to 50 ppm based on the polyester resin. In this case, ℃・
When the amount is less than i o ppm, the peel strength during secondary adhesion, which is the objective of the present invention, cannot be fully satisfied. Moreover, when it exceeds 50 ppm, the hardness of the unsaturated polyester resin molded product becomes poor. Naphthenic acid metal salts or octenoic acid metal salts are conventionally used as additives for unsaturated polyester resins. For example, copper naphthenate is added at 0.5 to 3 ppm to maintain storage stability, or cobalt naphthenate is added at 0.5 to 3 ppm to maintain storage stability.
It was added in an amount of 5 to 1% by weight to promote curing.

However, the present inventor has determined that polyester resin has a
It has been discovered that by using 50 ppm of naphthenic acid metal salt, a curing reaction suppressing effect, which was completely unexpected in the past, was exhibited.

Examples of the polymerization initiator for crosslinking and curing the unsaturated polyester resin composition of the present invention include benzoyl peroxide,
lauroyl peroxide, parachlorobenzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, 2,2'-bis(4,4-ditertiary)
butylperoxycyclohexylpropane), tertiary
Butyl peracetate, tertiary butyl perbenzoate, tertiary butyl perbenzamide, etc. are used, and in order to make a molding compound, reinforcing inorganic or organic fibers, fillers, thickeners, and mold release agents are used. , additives such as antioxidants, etc. may be combined.

Effects of the Invention When the unsaturated polyester resin composition of the present invention having a high thixotropy is used particularly in FRP molding, the adhesion is extremely good. The thixotropy is about 3 to 7, the problem of sagging during molding is solved, and a molded product with extremely excellent peel strength can be obtained.

Example The present invention will be specifically explained below using examples.

Example 1 0.6 mol of maleic anhydride and 0.4 mol of phthalic anhydride were reacted with 115 mol of propylene glycol in a conventional manner to obtain an unsaturated polyester. The molecular weight was i,ooo. 55 parts of this unsaturated polyester was dissolved in 45 parts of styrene, and copper naphthenate, cobalt naphthenate, 1
．． 5 parts of silica powder were added.

The mole fraction in this experiment was 0.6, OH/CO
The OH molar ratio is 1.15.

Base material hardness and peeling tests were conducted while varying the amount of copper naphthenate added as shown in Table 1.

Base material hardness was measured using a Percoll hardness meter.

The peel test was conducted as follows.

Molding method of base material Using the above resin, 5 plies of #450 chopped strand mat were laminated on a glass plate treated with a mold release agent, and left in a curing oven at 50°C for 1 hour to harden.

Surface treatment of base material The contact surface of the glass plate was polished with a resinoid grinder normally used for cutting and polishing FRP, and the other surface was polished with sandpaper #240.

In the display of peel test results in the table, ◎ indicates that 100% of the matrix is destroyed, ○, △, and × indicate 50% or more destruction, 20 to 50% destruction, and 20% or less destruction, respectively, and ×
× indicates that interfacial peeling occurred.

Example 2 The same procedure as in Example 1 was carried out except that the amount of styrene used was changed as shown in Table 2. The results are shown in Table 2.

Claims (1)

[Claims] The molar fraction of unsaturated dicarboxylic acid in the acid component is 0.5 to 0.
8, and the OH/COOH molar ratio is 1.1 to 1.2
An unsaturated polyester resin prepared by adding 25 to 50% by weight of a crosslinking agent and a polymerization initiator to the unsaturated polyester, and 10 to 50 ppm of organic copper in terms of metal purity based on the polyester resin. An unsaturated polyester resin composition with a high thixotropy, which is made by blending salt and, if necessary, other fillers, reinforcing materials, and additives.