JPH0819196B2 - Unsaturated polyester resin composition for gel coat - Google Patents

Description

TECHNICAL FIELD The present invention relates to an unsaturated polyester resin composition for gel coat, and particularly to an unsaturated polyester for gel coat having excellent pigment dispersibility, boiling water resistance and high durability. It relates to a resin composition.

[Conventional technology]

Conventionally, gel coat paints that add pigments to unsaturated polyester resins are FRP because they give durability at the same time as aesthetics.
It is used for painting bath units, FRP water tanks, FRP fishing boats, etc.

In particular, the gel coat coating used in the bath unit is required to have aesthetics as well as boiling water resistance and high durability, but the unsaturated polyester resin for gel coat coating that has been conventionally used does not contain pigments such as carbon and cyanine blue. When used, the dispersion is not sufficient and color unevenness occurs during painting.
Blistering occurs on the coated surface due to insufficient boiling water resistance.
Further, since it has poor durability, it is used with many problems such as cracks in the coating film during long-term use.

[Problems to be Solved by the Invention]

The present invention solves the above-mentioned drawbacks of the prior art, is excellent in pigment dispersibility, and has a high boiling water resistance and a high toughness of the coating film. The present invention provides a suitable unsaturated polyester resin composition for gel coat, which imparts properties.

[Means for solving the problem]

As a result of intensive studies, the inventors of the present invention have been able to solve the aforementioned problems by limiting the composition of the unsaturated polyester resin composition, and have high-quality finish and boiling water resistance and tough coating film physical properties, etc. The inventors have found that the following can be obtained and reached the present invention.

The present invention provides an unsaturated polyester resin composition for gel coat containing an unsaturated polyester (A) obtained by using a long-chain glycidyl ester and a bisphenol A derivative and a polymerizable monomer (B). ) Is a general formula as a long-chain glycidyl ester. [In the formula, R ₁ , R ₂ and R ₃ each independently represent an alkyl group having 1 to 15 carbon atoms] 3 to 20% by weight of unsaturated polyester (a resin excluding condensation water) The ratio of the total polybasic acid is 30% by mole of the adduct of bisphenol A with ethylene oxide or propylene oxide as the polyhydric alcohol component, and the unsaturated polybasic acid is used in the total polybasic acid component of 30%. Used at a mol% or higher, and number average molecular weight of 500 to 3
It has a viscosity (25 ° C, Gardner) of 3 to 30 poise and an acid value of 50 or less when diluted with styrene to a heating residue of 60%, and further contains a polymerizable monomer (B) of 20 To 70% by weight of the unsaturated polyester resin composition for gel coat.

The unsaturated polyester (A) obtained by using the long-chain glycidyl ester and the bisphenol A derivative used in the unsaturated polyester resin composition of the present invention is, for example, a long-chain glycidyl ester, a bisphenol A derivative, or other polyvalent An alcohol component and a polybasic acid component are charged at the same time and condensed at 150 to 220 ° C for 2 to 30 hours, or a bisphenol A derivative, another polyhydric alcohol component and a polybasic acid component are heated at 150 to 220 ° C for 2 to 20 hours. Condensed, acid value
After cooling at 100 to 50, a long-chain glycidyl ester is added, and the mixture is again condensed at 120 to 220 ° C. for several hours to obtain the product. These condensation methods are known, and the production method is not particularly limited in the present invention.

The unsaturated polyester (A) has a number average molecular weight of 500 to 3000, preferably 800 to 2000, and a viscosity (25 ° C, Gardner) of 3 to 30 when diluted with styrene to a heating residue of 60%. Poise, preferably 3-20 poise,
The acid value is 50 or less, preferably 30 or less. If the number average molecular weight is less than 500, the curability will be insufficient, and the boiling water resistance and toughness of the cured product will decrease. On the other hand, when the number average molecular weight exceeds 3000, it is difficult to keep the viscosity (25 ° C, Gardner) below 30 poise, and when the gel coat is applied (spray coating), the dispersion of the coating liquid is poor and uniform. It tends to be difficult to apply to.

If the viscosity of the unsaturated polyester diluted with styrene to a heating residue of 60% is less than 3 poises (25 ° C., Gardner), the molecular weight does not increase and the boiling water resistance and coating film toughness decrease. On the other hand, when the viscosity exceeds 30 poise, it becomes difficult to disperse the pigment due to the high viscosity when it is made into a paint, and a solvent such as styrene is used in large amount, so that the durability of the coating film is deteriorated.

Further, when the acid value of the unsaturated polyester exceeds 50, carbon black, the dispersibility of cyanine blue, etc. becomes poor, and particularly when carbon black is used,
Partial gelation occurs over time. Further, since the obtained coating film has poor boiling water resistance, blisters and cracks occur.

Examples of the long-chain glycidyl ester represented by the general formula (I) used in the present invention include "Cadura E" (trade name) manufactured by Shell Kagaku. This glycidyl ester has excellent reactivity, improves compatibility with other resins and dispersibility of pigments such as carbon black and cyanine blue, and further is chemically stable to improve coating film toughness. This glycidyl ester is 3
It is used in an amount of 20 to 20% by weight (ratio in the resin excluding condensed water), preferably 3 to 15% by weight. If this ratio is less than 3% by weight, the pigment dispersibility is poor and color unevenness occurs in the coating film after the gel coat coating is applied. On the other hand, when it exceeds 20% by weight, when used as a gel coat paint, the coating film becomes soft and water marks remain on the coating film after the boiling water test.

In the unsaturated polyester of the present invention, a bisphenol A derivative, that is, an adduct of bisphenol A represented by the following general formula and ethylene oxide or propylene oxide is used as a part of the polyhydric alcohol component.
This adduct is represented by the following formula, for example.

[Wherein A is -CH ₂ -CH ₂ -or Where m is an integer of 1 to 10 and n is an integer of 1 to 10, and m and n may be the same or different. ] By using this adduct, boiling water resistance and toughness are significantly improved.

These bisphenol A derivatives are used in the polyhydric alcohol component in an amount of 30 mol% or more, preferably 50 mol% or more. If it is less than 30 mol%, the properties peculiar to bisphenol A are not fully utilized and the boiling water resistance is not sufficient, so that blisters and cracks occur.

As the ethylene oxide adduct of bisphenol A, Unipol BPE-20NK and Unipol BP manufactured by Sanyo Chemical Co., Ltd.
E-40, Unipol BPE-60 (trade name), and the like as propylene oxide adducts are also Newpol BP-2P, Newpol BP-3P, Newpol BP from Sanyo Chemical Co., Ltd.
-4P (trade name), etc., and one or more of these are used as a polyhydric alcohol component.

Other polyhydric alcohol components include, for example, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, neopentyl glycol, trimethylolpropane, pentaerythrium. Trit, glycerin, etc. are used.

Examples of the unsaturated polybasic acid used for the unsaturated polyester as the component (A) in the present invention include maleic anhydride, maleic acid, fumaric acid, itaconic acid, citraconic acid and the like. One or more of these are used in an amount of 30 mol% or more, preferably 50 mol% or more, based on the total polybasic acid component. If it is used in an amount of less than 30 mol%, the gel coat coating will not be sufficiently cured, and the boiling water resistance, chemical resistance and stain resistance will be reduced.

Examples of other polybasic acid components include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, het acid, adipic acid, sebacic acid, and benzoic acid.

The unsaturated polyester resin composition of the present invention contains the polymerizable monomer (B) in an amount of 20 to 70% by weight, preferably 30 to 60% by weight. When the content of the polymerizable monomer (B) is less than 20% by weight, the reaction with the unsaturated polyester (A) is not sufficient, a high hardness coating film cannot be obtained, and it may be used in a bath unit or the like. When used, water stains and the like adhere to the appearance of the cured product. On the other hand, when the amount exceeds 70% by weight, the coating film tends to have poor wall thickness, a high-quality coating film cannot be obtained, and the curability tends to decrease.

Examples of the polymerizable monomer (B) used in the present invention include styrene, vinyltoluene, α-methylstyrene,
Divinylbenzene, t-butylstyrene, vinyl acetate,
Examples thereof include vinyl chloride, acrylic acid ester, methacrylic acid ester, methylenebisacrylamide, glycidyl methacrylate, 2-hydroxymethacrylate, and 2-hydroxyacrylate.

As the curing catalyst used in curing the unsaturated polyester resin composition for gel coat of the present invention, a combination of a radical polymerization initiator and a metal soap, amine, amine salt or the like, for example, methyl ethyl ketone peroxide, benzoyl peroxide, cyclohexane peroxide is used. , T-butyl peroxide and the like and a combination of cobalt octenoate, manganese naphthenate, copper naphthenate, dimethylaniline, diethylaniline, dimethylacetamide and the like are preferable.

Further, benzoin instead of the accelerator and the curing agent,
It is also possible to add a photoinitiator such as benzoin methyl ether or benzoin propyl ether, and use a low-pressure mercury lamp, a fluorescent lamp, a high-pressure mercury lamp or the like as an irradiation light source for ultraviolet curing.

The unsaturated polyester resin composition for gel coat of the present invention, as a coloring pigment, for example, titanium white, red iron oxide, aniline black, carbon black, manganese blue, cyanine blue, iron black, ultramarine blue, Hansalet, chrome yellow, chrome greeme, It may include mapico yellow and the like.

Further, the filler may include, for example, calcium carbonate, kaolin, clay, alumina, talc, mica and the like.

These color pigments and fillers are dispersed in the unsaturated polyester resin composition by using a three-roll, a dissolver, a ball mill, a sand mill and the like.

Further, as the leveling agent, silicone, cellulose acetate, butyrate, various surfactants and the like may be used, and as the anti-sagging agent, silicon dioxide and the like may be used.

〔Example〕

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples. "Parts" and "%" in the following examples mean "parts by weight" and "% by weight" unless otherwise specified.

Comparative Example 1 equipped with a stirrer, gas introduction pipe, reflux condenser and thermometer
In a 2 liter flask, 326 parts (4.29 mol) of propylene glycol, 446 parts (4.29 mol) of neopentyl glycol, 388 parts (2.34 mol) of isophthalic acid and 0.2 part of hydroquinone were placed, and the acid value was 10 ° C at 210 ° C while blowing nitrogen gas. (K
OH mg / g). Then, the mixture was cooled to 120 ° C., 633 parts (5.46 mol) of fumaric acid was added, the temperature was raised again to 200 ° C., and the esterification reaction was allowed to proceed while measuring the viscosity of the contents in the kettle at the same temperature. Viscosity is 60 parts styrene 40 parts
It was dissolved in 1 part, diluted with heating residue of 60%, and the end point was reached when the Gardner viscosity measured at 25 ° C reached 6.5 poise. Styrene was added to the obtained resin so that the heating residue was 60%. Acid value 18.5, viscosity 7.2 poise (Gardner, 25
(° C) to obtain a pale yellow transparent resin composition. HL of this resin
The number average molecular weight obtained by C (high speed liquid chromatograph, using Hitachi Chromatograph 635-0200 manufactured by Hitachi, Ltd., polystyrene as a standard substance, the same applies hereinafter) was 1530.

Comparative Example 2 In the same manner as in Comparative Example 1, 326 parts (4.29 mol) of propylene glycol, 446 parts (4.29 mol) of neopentyl glycol, 388 parts (2.34 mol) of terephthalic acid, 1.2 parts of dibutyltin oxide and 0.2 parts of hydroquinone were placed in a 2 l flask. Then, while blowing nitrogen gas, the acid value is 6 (KOHmg /
The reaction was continued until g). Then, the mixture was cooled to 120 ° C., 633 parts of fumaric acid (5.46 mol) was added, and the temperature was raised to 200 ° C. again.
Similarly to Comparative Example 1, the esterification reaction was carried out while measuring the styrene dilution viscosity of the contents in the kettle. The end point was when the viscosity reached 7.0 poise. The obtained resin was diluted with styrene in the same manner as in Comparative Example 1 to give a viscosity of 7.8 poise (Gardner, 25
℃), a light yellow transparent resin composition having an acid value of 12.8 was obtained. The number average molecular weight obtained by HLC of this resin was 1,720.

Comparative column 3 As in Comparative Example 1, 95.8 parts (0.92 mol) of neopentyl glycol, Newpol BPE-20NK (manufactured by Sanyo Kasei Co., ethylene oxide adduct of bisphenol A, average molecular weight 327.1, ethylene oxide (2 mol addition) were added to a 2 l flask. Body 82.5%, 3 mole adduct 15.8%, 4 mole adduct 1.8%) 1
212.3 parts (3.71 mol), fumaric acid 487.2 parts (4.2 mol)
And 0.2 parts of hydroquinone were added, the temperature was raised to 150 to 200 ° C. in 6 hours while blowing nitrogen gas, and the esterification reaction was proceeded while measuring the styrene dilution viscosity of the contents in the kettle at the same temperature as in Comparative Example 1. It was The end point was when the viscosity reached 8.5 poise. The obtained resin was diluted with styrene in the same manner as in Comparative Example 1 to give a viscosity of 8.8 poise (Gardner, 25 ° C.),
A colorless and transparent resin composition having an acid value of 8.8 was obtained. HLC of this resin
The number average molecular weight obtained in 1. was 1780.

Example 1 In the same manner as in Comparative Example 1, a 2 L flask was charged with a cardura E (made by Shell Chemical Co., alkyl gludyl ester, R ₁ = CH ₃ , R ₃ = CH ₃ , R ₂ = carbon number 12 to 12 in the general formula (I)). 14 alkyl groups, molecular weight 250) 111.7 parts (0.45 mol), neopentyl glycol 46.5 parts (0.45 mol), Newpol BPE-20NK11
71.9 parts (3.58 mol), fumaric acid 471.0 parts (4.06 mol)
And 0.2 parts of hydroquinone were added, the temperature was maintained at 150 ° C for 1 hour while blowing nitrogen gas, and the temperature was raised to 200 ° C over 4 hours. At the same temperature, the styrene dilution viscosity of the contents in the kettle was measured in the same manner as in Comparative Example 1. While proceeding the esterification reaction. Viscosity
The end point was when it became 8.2 poise. The amount of distilled reaction water was 125 g. The obtained resin was diluted with styrene in the same manner as in Comparative Example 1 to obtain a pale yellow transparent resin composition having a viscosity of 8.5 poise and an acid value of 7.8. The number average molecular weight obtained by HLC of this resin was 1750.

Example 2 As in Comparative Example 1, a 2 l flask was charged with 221.9 parts (0.89 mol) of Cardura E, Newpol BP-2P (manufactured by Sanyo Kasei Co., average molecular weight 349.5, propylene oxide adduct of bisphenol A, propylene oxide 2 mol). Adduct 95.3%, 3
4.2% molar adduct, 0.8% 4 molar adduct 1241.2 parts (3.55
Mol), fumaric acid (468.1 parts) (4.04 mol) and hydroquinone (0.2 parts) were added, the mixture was kept at 150 ° C. for 1 hour while blowing nitrogen gas, and then heated to 200 ° C. over 4 hours, at the same temperature as in Comparative Example 1. The esterification reaction proceeded while measuring the styrene dilution viscosity of the contents in the kettle. The end point was when the viscosity reached 7.8 poise. In addition, the amount of distilled reaction water was 120 g. The obtained resin was diluted with styrene in the same manner as in Comparative Example 1 to obtain a light yellow transparent resin composition having a viscosity of 8.0 poise and an acid value of 6.9. The number average molecular weight obtained by HLC of this resin was 1580.

Example 3 As in Comparative Example 1, in a 2 l flask, 200.2 parts (0.80 mol) of cardura E, 107.7 parts (0.73 mol) of phthalic anhydride, and Newpol BP-3P (manufactured by Sanyo Kasei Co., Ltd., propylene oxide addition of bisphenol A) were added. , Average molecular weight 392.3, 2 mol adduct 38.1%, 3 mol adduct 40.8%, 4 mol adduct 17.0
%, 5 mol adduct 4.1%) 1256.5 parts (3.20 mol) was added, the temperature was raised to 150 ° C. while blowing nitrogen gas, and the temperature was kept at the same temperature for 2 hours, then cooled to 120 ° C. and fumaric acid 337.8.
Parts (2.91 mol) and 0.2 parts of hydroquinone were added, the temperature was again raised to 150 ° C., and further raised to 200 ° C. over 4 hours,
The esterification reaction was carried out at the same temperature as in Comparative Example 1 while measuring the styrene dilution viscosity of the contents in the kettle. Viscosity
The end point was when it became 7.9 poise. The amount of distilled reaction water was 105 g. The obtained resin was diluted with styrene in the same manner as in Comparative Example 1 to obtain a light yellow transparent resin composition having a viscosity of 8.3 poise and an acid value of 10.6. The number average molecular weight obtained by HLC of this resin was 1260.

Table 1 shows the resin compositions and resin characteristics in Comparative Examples 1 to 3 and Examples 1 to 3.

Test Example (Dispersibility and Coating Performance of Resin Composition) The dispersibility and coating performance of the resin compositions obtained in Comparative Examples 1 to 3 and Examples 1 to 3 were tested as follows.

(1) Paint composition and adjustment 100 parts of resin composition, cyanine blue (manufactured by Dainichiseika)
5 parts, 10 parts of mapico yellow (manufactured by Toda Kogyo Co., Ltd.) and 20 parts of titanium white (R-930, manufactured by Fuji Titanium White Co., Ltd.) were kneaded twice with a triple roll, and then styrene was used for 60 seconds with an Iwata cup viscometer (25 ° C ).

(2) Dispersibility test method To the coating liquid obtained in (1), 60% cobalt octate 1% and 55% methyl ethyl ketone peroxide 1% were added and uniformly dispersed, and then 50 to 50 cm on a glass plate of 30 cm x 30 cm. 60 g
After spray coating (manufactured by Iwata Co., Ltd., Wider 77 type, caliber 2 mm, coating pressure 4 kg / cm ² ), the appearance (color separation) of the cured coating film was observed after standing at room temperature for 3 hours.

◯: Evenly dispersed.

Δ: Some blue, yellow, and white color unevenness is seen.

X: Blue, yellow, and white color irregularities are remarkable.

(3) Preparation of test plate 6% cobalt octate 1% to the paint obtained in (1)
And 55% methyl ethyl ketone peroxide 1% were added and uniformly dispersed, and then a release agent (wax) was applied 30 cm
Spray coating was performed on a glass plate having a size of 30 cm in the same manner as in the dispersibility test of the above item (2), and after that, the mixture was left at room temperature for 2 hours and then heated at 50 ° C. for 3 hours to further accelerate the curing. After cooling, a 0.7 mm thick glass mat (glass content 40
%) 3 layers, and after adding 6% cobalt octate 1% and 55% methyl ethyl ketone peroxide 1% to a commercially available unsaturated polyester resin (manufactured by Hitachi Chemical Co., Ltd., Polyset 559), 80 g of a uniformly dispersed liquid The glass mat was placed on a glass mat, the glass mat was sufficiently impregnated with the resin solution while squeezing with a roll, and the glass mat was left at room temperature for 2 hours and then heated at 50 ° C. for 3 hours for further curing. After cooling, the layered coating film was peeled off from the glass plate to give a test piece.

(4) Coating film performance test The following coating film performance tests were conducted on the gel-coated surfaces of the layered coating films of the resin compositions of Comparative Examples and Examples, and the results are shown in Table 2.

Boiling water resistance: The test piece obtained in (3) is cut into 10 cm x 10 cm pieces, immersed in boiling water, and timed (500 hours, 1000 hours and 1500 hours).
The state of blisters and cracks on the gel-coated surface was observed.

Alkali resistance: The test piece obtained in (3) was cut into 5 cm x 5 cm, and it was 5% at 35 ℃.
It was dipped in a NaOH aqueous solution, and blisters, cracks and discoloration on the gel-coated surface were observed every time (24 hours, 48 hours, 72 hours).

Acid resistance: The test piece obtained in (3) is cut into 5 cm x 5 cm, and 35 ° C, 5%
It was immersed in an aqueous HCl solution, and blisters, cracks, and discoloration on the gel-coated surface were observed every time (24 hours, 48 hours, 72 hours).

Impact resistance: The test piece obtained in (3) is cut into 10 cm × 10 cm, and JIS
The breaking strength of the gel coat surface was measured according to K-7211.

Weight type: Spherical weight ball type 1 (0.5 kg) Test method Height (cm): 100 cm ×: Destruction ○: No destruction Heat cycle property: 10 cm × 10 cm for the test piece obtained in (3) Cut and 80 ℃
After being heated for 1 hour at -20 ° C., it was immersed in an acetone-dry ice solution at −20 ° C. for 1 hour, and when this was repeated 4 times, the cracked state of the gel-coated surface was observed.

The results in Table 2 show that the resin composition according to the present invention is excellent in pigment dispersibility and has boiling water resistance, chemical resistance and high durability.

〔The invention's effect〕

The unsaturated polyester resin composition for gel coat of the present invention is excellent in pigment dispersibility, and the coating film has high hardness, boiling water resistance and high durability. The resin composition of the present invention is not only particularly suitable for gel coat of a bath unit,
It can also be used in fields requiring durability such as purified water tanks and water tanks, and its practical curing is remarkable.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C09D 4/00 PEB (72) Inventor Ikuko Takahashi 4-13-1 Higashimachi, Hitachi City, Ibaraki Hitachi Seisaku Kogyo Co., Ltd. Yamazaki factory (56) References JP-A-62-115059 (JP, A)

Claims (1)

[Claims] 1. An unsaturated polyester resin composition for gel coat, comprising an unsaturated polyester (A) obtained by using a long chain glycidyl ester and a bisphenol A derivative and a polymerizable monomer (B). A) is a general formula as a long-chain glycidyl ester. [In the formula, R ₁ , R ₂ and R ₃ each independently represent an alkyl group having 1 to 15 carbon atoms] 3 to 20% by weight of the unsaturated polyester (in the resin excluding condensation water) The ratio of bisphenol A and ethylene oxide or propylene oxide as a polyhydric alcohol component is 30 mol% in the alcohol component.
The above is used, and the unsaturated polybasic acid is used in an amount of 30 mol% or more in the total polybasic acid component, and the number average molecular weight is 500 to 300.
It has a viscosity (Gardner, 25 ° C.) of 3 to 30 poise and a acid value of 50 or less when diluted with styrene to a heating residue of 60%, and further contains a polymerizable monomer (B) of 20 or less. An unsaturated polyester resin composition for gel coat, containing about 70% by weight.