JPH0674301B2 - Unsaturated polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a product having good surface smoothness by reducing the conspicuousness of glass fibers on the surface of the gel coat in the gel coated fiber reinforced plastic at a low contact pressure and a room temperature and a medium temperature. provide.

[Conventional technology]

To relax the glass pattern on the surface of the gel coat in FRP molding with gel coat, thickly coat the gel coat and after sufficient curing, make a resin-rich layer with a surface mat, etc., and after curing, use a chopped strand mat or roving cloth and It was necessary to laminate glass fibers such as glass cloth and slowly cure them, and still the surface smoothness was not sufficient.

As a resin having such a good surface smoothness, JP-A-63-63
-196614 discloses a resin composition of an unsaturated polyester resin and a vinyl ester resin, and an ethylenically unsaturated liquid monomer copolymerizable with the unsaturated polyester resin and the vinyl ester resin. Since it is used, there is a drawback that the cost is high.

[Problems to be Solved by the Invention]

In the present invention, it is not necessary to thicken the gel coat and to provide the resin rich layer, which has been performed by the conventional technique, and the curing after the lamination may be accelerated. The object of the present invention is to obtain an inexpensive resin composition which can be obtained by molding with a conventional technique to obtain a product having a more perfect surface smoothness.

[Means for Solving the Problems]

Therefore, the present invention comprises (a) an unsaturated polybasic acid, a saturated polybasic acid, and neopentyl glycol as a polyhydric alcohol component in an amount of 20 to 100 mol%, and the balance obtained from other polyhydric alcohols. Unsaturated polyester resin A composed of unsaturated polyester and polymerizable monomer composed of saturated polyester and polymerizable monomer (b) Unsaturated polybasic acid, saturated polybasic acid or anhydride thereof and polyhydric alcohol and dicyclo Unsaturated polyester resin B composed of unsaturated polyester obtained from pentadiene and a polymerizable monomer (C) Weight ratio of unsaturated polyester resin A and B 3/1 to 1/3
An unsaturated polyester resin composition comprising 0.1 to 3.0 parts of a thixotropic agent and about 10 to 40 parts of a polymerizable monomer (D) per 100 parts of the mixture.

[Action]

The unsaturated polyester (A) in the present invention has an unsaturated polybasic acid, a saturated polybasic acid, and neopentyl glycol as a polyhydric alcohol component in an amount of 20 to 100 mol%, and the rest is obtained from another polyhydric alcohol. Made from unsaturated polyester and polymerizable monomer.

For example, an α, β-unsaturated dibasic acid is mixed with a saturated dibasic acid, if necessary, and a polyhydric alcohol is subjected to a condensation reaction in a temperature range of 150 to 250 ° C in an inert gas stream. The obtained acid value is in the range of 5 to 50 and the molecular weight is in the range of 800 to 3000, but it is derived by using neopentyl glycol in an amount of 20 to 100 mol% in the polyhydric alcohol. When the content of neopentyl glycol in the polyhydric alcohol, which is one of the essential components for obtaining the α, β unsaturated polyester, is less than 20 mol%, the surface smoothness of the article obtained by molding and curing is poor. It is not preferable.

α, β used to obtain unsaturated polyester,
Examples of β-unsaturated dibasic acids include maleic acid, halogenated maleic acid, fumaric acid, maleic anhydride, and the like, and examples of saturated dibasic acids include phthalic acid, phthalic anhydride, isophthalic acid, Examples thereof include terephthalic acid, tetrahydrophthalic anhydride, succinic acid, adipic acid and sebacic acid.

Further, as the polyhydric alcohol for obtaining the unsaturated polyester, other than neopentyl glycol, ethylene glycol, 1,2-propylene glycol, 1,3-
Propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-butanediol, bisphenol A, propylene oxide or ethylene oxide adduct of bisphenol A,
Glycerin, pentaerythritol, etc. can be used.

An unsaturated polyester resin A is obtained by dissolving a polymerizable monomer in the obtained unsaturated polyester in an amount of 20 to 50% by weight within the range of use.

The unsaturated polyester resin B in the present invention has a molecular weight of 250 to 1000 obtained from unsaturated polybasic acid, saturated polybasic acid or anhydride, polyhydric alcohol and dicyclopentadiene.
Of unsaturated polyester and polymerizable monomers.

The amount of dicyclopentadiene required is about 0.10 to 1.1 moles per mole of unsaturated polybasic acid, saturated polybasic acid or anhydride or mixture thereof. In addition, it is soluble in 20 to 50% by weight of a polymerizable monomer as an unsaturated polyester obtained from unsaturated polybasic acid, saturated polybasic or anhydride, polyhydric alcohol and dicyclopentadiene. As a result, unsaturated polyester resin polyester B is obtained.

For example, a dicyclopentadiene resin can be produced as follows.

Dicyclopentadiene 1.05 mol Water 1.10 mol Maleic anhydride 1.00 mol Ethylene glycol 0.33 mol Propylene glycol 0.22 mol Using dicyclopentadiene and water in a 4-necked flask, attach a condenser, and inject nitrogen while stirring, Maleic anhydride was added at 90 ° C so that the temperature was 130 ° C or lower, and the mixture was slowly added to generate heat, and after completion, heating at 130 ° C was continued for 3 hours. Next, ethylene glycol and propylene glycol are added to gradually raise the temperature, react at 210 ° C, cool at an acid value of 25 or less, and hydroquinone 0.0
1 part, 25% styrene monomer is added to make resin.

The unsaturated polyester resin composition of the present invention is a mixture of unsaturated polyester resin A and unsaturated polyester resin B in a weight ratio of 3/1 to 1/3 to 100 parts by weight of a thixotropic agent of 0.1 to 3.0 parts and It is obtained by mixing about 10 to 40 parts of a polymerizable monomer.

The reason why the mixture of neopentyl glycol-based resin and dicyclopentadiene-based resin is smooth is not clear for some reason.However, because neopentyl glycol-based resin has a slow radical polymerization rate, curing of the resin is generally balanced. It is considered that the shrinkage stress generated at the time of curing is relaxed by mixing a general-purpose resin (high molecular weight resin) and a dicyclopentadiene resin (low molecular weight resin) because it is easy to remove.

A typical additive for imparting thixotropy to a thixotropic agent, that is, a resin is finely divided silica. Silanol group (≡SiOH) on the surface with a particle size of 10 to 20 mm, which is called the product name Aerosil (manufactured by Nippon Aerosil Co., Ltd.)
It is silicic acid with. Addition amount and 0.1 to 3 parts are added to 100 parts of the mixture of unsaturated polyester A and unsaturated polyester B.

Examples of the crosslinkable monomer in the present invention include styrene, α-methylstyrene, chlorostyrene, vinyltoluene, acrylic acid esters, methacrylic acid esters, diallyl phthalate, divinylbenzene, trimethylolpropane trimethacrylate, and trimethylolpropane. Examples thereof include triacrylate and pentaerythritol triacrylate. Styrene is particularly effective, and it is preferably used alone or in combination with other monomers.

The weight monomer is limited to about 10 to 40 parts because it is necessary for proper viscosity adjustment due to seasonal temperature changes and thixotropic agent changes.

〔Example〕

A Example 1 (a) Production of unsaturated polyester resin A Resin A, which is one component of the composition of the present invention, was produced as follows.

Maleic anhydride 60 mol Isophthalic acid 40 mol Propylene glycol 42 mol Neopentyl glycol 63 mol Hydroquinone 0.01 part by weight The unsaturated polyester obtained by esterification at 200 ° C. under an inert gas was 65 parts by weight, This is dissolved in 35 parts by weight of styrene monomer, and is referred to as unsaturated polyester resin A.

(B) Production of Unsaturated Polyester Resin B Resin B, which is one component of the composition of the present invention, was produced as follows.

Phthalic anhydride 20 mol Maleic anhydride 80 mol Ethylene glycol 55 mol Dicyclopentadiene 88 mol Water 85 mol Dicyclopentadiene and water are charged, and the temperature is raised to 90 ° C.
Maleic anhydride is added little by little to keep the temperature below 130 ° C, and after the addition is complete, phthalic anhydride and ethylene glycol are added and the temperature is gradually raised from 160 ° C to 210 ° C to continue the reaction. Cool to AV20, add 0.01 parts by weight of hydroquinone and 25% of styrene monomer at 140 ° C to make resin B.

(C) Production of unsaturated polyester resin C having good surface smoothness Unsaturated polyester resin A 50 parts by weight Unsaturated polyester resin B 50 parts by weight Egile 200 1 part by weight Styrene monomer 20 parts by weight B Comparative Example 1 (a) Unsaturated polyester Production of Resin D Maleic anhydride 60 mol Isophthalic acid 40 mol Propylene glycol 105 mol Hydroquinone 0.01 parts by weight 65 parts by weight of unsaturated polyester obtained by esterification of the above composition with an inert gas at 200 ° C. 35
What was melt | dissolved in the styrene monomer of weight part is made into unsaturated polyester resin D.

(B) Comparative resin Manufacture of unsaturated polyester resin E 100 parts by weight of unsaturated polyester resin D 1 part by weight of estilel 20 parts by weight of styrene monomer C Surface smoothness comparison test method (a) Spacer with a thickness of 5 mm at both ends of a smooth glass plate Place and release the mold.

(B) Pour the gel coat resin and spread it flat with a glass rod.

(C) Leave it in the open at 60 ° C for 30 minutes, take it out, and cool it to room temperature.

(D) A glass fiber is laminated with each of the unsaturated polyester resins D and E.

Glass composition M / R / M / R / M M ... No. 450 mat R ... No. 570 roving cloth Laminating condition Laminate conditions: Spread twice the resin weight of the mat on the gel coat and spread it, and impregnate the mat to impregnate it. A certain amount of resin is poured and spread, and a roving cloth is placed and impregnated. Repeat the operation.

Curing conditions 55% MEKPO / 6% Cobalt naphthenate = 1 / 0.5
Parts by weight, room temperature lamination, room temperature 24 hours standing or room temperature lamination, 60
Leave for 1 hour at ℃ open.

(E) The laminated plate is removed from the glass plate.

(F) Cut into the same size and compare smoothness.

Comparison of smoothness Place the laminated plate at the same position and compare the sharpness of the image reflected on the gel coat surface and the protruding state of the glass pattern.

D Test Results The laminated plate made of the resin of the present invention had a clear image on the gel-coated surface, less glass pattern, and very good surface smoothness, as compared with the laminated plate made of the comparative resin.

〔The invention's effect〕

The unsaturated polyester resin composition according to the present invention alleviates the conspicuousness of glass fibers on the surface of the gel coat, and a product having a good surface smoothness can be obtained.

Claims (1)

[Claims] 1. An unsaturated polybasic acid, a saturated polybasic acid, and neopentyl glycol as a polyhydric alcohol component (a) in an amount of 20 to 20.
Unsaturated polyester resin A (b) unsaturated polybasic acid, saturated polybasic acid or its anhydride, which has 100 mol% and the rest is an unsaturated polyester obtained from other polyhydric alcohol and a polymerizable monomer Unsaturated polyester resin B composed of an unsaturated polyester obtained from a compound, a polyhydric alcohol and dicyclopentadiene and a polymerizable monomer (C) Weight ratio of unsaturated polyester resins A and B 3/1 to 1/3
An unsaturated polyester resin composition comprising 0.1 to 3.0 parts of a thixotropic agent and about 10 to 40 parts of a polymerizable monomer (D) per 100 parts of the mixture.