JP4582420B2 - Coating material, gel coat material and molded article using unsaturated polyester resin - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coating material, a gel coat material, and a fiber reinforced plastic (FRP) molded product using the same on the surface, using an unsaturated polyester resin composition that provides a cured product excellent in gloss retention and yellowing resistance. It is.

Unsaturated polyester resins have excellent chemical, physical, mechanical, and electrical properties that include a wide range of curing temperature conditions and fast curing speeds, so they are used in various FRP molded products, paints, and gel coat materials. ing. However, since the conventional unsaturated polyester resin is inferior in weather resistance, it has not only a significant decrease in gloss when exposed to the outdoors for a long period of time, but also has the disadvantage of causing yellowing. In order to improve this defect, JP-A-7-157645 derives from an acid component composed of an alicyclic saturated acid and an aliphatic unsaturated acid, and an alcohol component selected from aliphatic alcohols and alicyclic alcohols. An unsaturated polyester resin composition is proposed, and further, JP-A-9-26392 is derived from an acid component composed of hexahydrophthalic anhydride, hexahydroterephthalic acid and an unsaturated dibasic acid, and a polyhydric alcohol component. An unsaturated polyester resin composition for gel coat is proposed. However, these unsaturated polyester resin compositions are improved in yellowing resistance but not in gloss retention.

Further, European Patent No. 0400904 proposes an unsaturated polyester resin composition for gel coat using 2-methyl-1,3-propanediol as an alcohol component. U.S. Pat. No. 6,268,464 discloses 30 to 70 mol% of at least two kinds of diols, 0.5 to 8 mol% of 2-butyl-2-ethyl-1,3-propanediol, aromatic carboxylic acids and others. An unsaturated polyester resin composition obtained from these two types of carboxylic acids has been proposed. In these inventions as well, only yellowing was improved and gloss retention was insufficient.
In these prior arts, the yellowing resistance has been improved by improving the composition of the raw material, but the gloss retention is insufficient, so that choking occurs, and gloss degradation occurs in a relatively short time. have. For this reason, none of them satisfies both yellowing resistance and gloss retention, which are factors of weather resistance.

In recent years, regulations on the release of styrene monomer into the atmosphere are becoming stricter due to environmental problems, so that low styrene volatilization and low styrene content resins are required. In order to obtain a low styrene volatilization or a low styrene-containing unsaturated polyester resin, a method of reducing the styrene content using a DCPD low molecular weight unsaturated polyester, a method of adding paraffin wax, and the like are known. These methods can reduce the volatilization amount and content of the styrene monomer, but cannot satisfy the weather resistance.
JP-A-7-157645 Japanese Patent Application Laid-Open No. 9-263692 European Patent No. 0400904

  An object of the present invention is to provide an unsaturated polyester resin composition improved in both gloss retention and yellowing resistance in a weather resistance test, a coating material using the same, and a molded product thereof.

  As a result of intensive studies on the unsaturated polyester resin composition in order to solve the above-mentioned problems, the present inventors have found that when the temperature of the cured product of the unsaturated polyester resin composition drops from 70 ° C. to 20 ° C. When the unsaturated polyester resin composition is adjusted so that the “stress” is 17 MPa or less and the “shrinkage stress during cooling / elastic limit” is 1 or less, the gloss retention rate is 60% or more and the gloss retention rate is 20% or less. It has been found that an unsaturated polyester resin composition excellent in both yellowing and having a low polymerizable unsaturated monomer content can be obtained, and the present invention has been completed.

That is, the present invention provides an unsaturated polyester resin composition comprising an unsaturated polyester (A) and a polymerizable unsaturated monomer (B) which is a styrene monomer and / or an acrylic monomer. The amount of the polymerizable unsaturated monomer (B) is in the range of 30 to 40% by weight, and the unsaturated polyester (A) is derived from a dibasic acid component and a polyhydric alcohol component. (1) The dibasic acid component is composed of 30 to 65 mol% of an alicyclic saturated dibasic acid and 35 to 70 mol% of an aliphatic unsaturated dibasic acid, and (2) a polyhydric alcohol component (A) a symmetric glycol comprising neopentyl glycol, (b) an ethylene glycol or 1,3-propylene glycol as a glycol (b1) having no side chain, and the main chain having an odd number of carbon atoms, the side chain As a short chain alkyl group One, or selected from the two different short chain 2-butyl-2-ethyl-1,3-propanediol or 2-methyl-1,3-propanediol as asymmetric glycol (b2) having an alkyl group Consisting of at least one glycol,
(B) the polyvalent alcohol component is the symmetric glycol (a) 60-80 mol% and a glycol having no side chain (b1) made of 20 to 40 mol%,
(B) the polyvalent what alcohol component consisting of 20 to 60 mol% asymmetric glycol (b2) having a symmetric glycol (a) 40 to 80 mol% and a side chain, or (c) the polyhydric alcohol component Is composed of 60 to 80 mol% of the symmetric glycol (a), 10 to 35 mol% of the glycol (b1) having no side chain, and 5 to 10 mol% of the asymmetric glycol (b2) having a side chain,
Coating material, gel coat material, and fiber comprising an unsaturated polyester resin composition in which the "shrunk shrinkage stress" of the cured product is 17 MPa or less and the "shrunk shrinkage stress / elastic limit" is 1 or less Provide reinforced plastic moldings.

  Before describing the present invention in detail, definitions of technical terms used in the present invention will be described below.

[Shrinkage stress during cooling]
The technical term “shrinkage stress during cooling” used in the present invention is “shrinkage stress” generated when the temperature of the cured polyester resin composition drops from 70 ° C. to 20 ° C. It is measured by.

<Measurement method>
(1) Add 55% methyl ethyl ketone peroxide (curing agent) 1.0%, 6% cobalt naphthenate (curing accelerator) 0.1% to the unsaturated polyester resin composition of the present invention, and stir at 25 ° C. Of JISK-6901 is adjusted with t-butylcatechol so that the gel time is 30 minutes when measured according to the normal temperature gelation time (Method A). The defoamed resin composition is applied on a glass plate so that the thickness of the cured film is 0.3 mm, the upper surface is covered with a 150 μm polyethylene terephthalate film, and the cured film is left at room temperature for 24 hours. Create
(2) The obtained cured film is cut into a size of 70 mm × 10 mm × 0.3 mm to prepare a test piece. The glass transition temperature (Tg) of this test piece is measured with a transition temperature measuring device (“DMS600” manufactured by Seiko Instruments Inc.).

(3) Next, the test piece is attached and fixed to a tensile test apparatus (“Tensilon RTM-100PL” manufactured by Orientec Co., Ltd.). The temperature of the temperature-controlled room with the test piece mounting portion is set to a temperature 10 ° C. higher than the Tg of the test piece, and the test piece is maintained at the set temperature for 10 minutes.
(4) Since the test piece is stretched, the sample length is increased by this elongation and the test piece is fixed again. Subsequently, it converts into per area (for example, 1 mm), lowering | hanging the temperature of the temperature-controlled room which has this test piece at the temperature fall rate: 5 degree-C / min. The difference between the stress when the temperature-controlled room is 70 ° C. and the stress when the temperature is 20 ° C. is defined as “shrinkage stress during cooling”.

[Elastic limit]
The technical term “elastic limit” used in the present invention means an elastic limit measured by the following measuring method.
"Measuring method"
(1) A cured film obtained by the same method as (1) in the measurement of the “shrinkage stress during cooling” is further allowed to cure in a constant temperature room at 60 ° C. for 30 minutes.
(2) The test piece is cut from the obtained cured film into a test piece size of 70 mm × 10 mm × 0.3 mm.
(3) The test piece is attached to a tensile test apparatus (“Tensilon RTM-100PL” manufactured by Orientec Co., Ltd.), and the test piece is measured at a normal temperature (25 ° C.) at a test speed of 5 mm / min. The maximum stress in the region according to the linear expression is obtained at the initial stage of the stress-strain curve, and this is defined as the “elastic limit”.
By dividing the value of the “shrinking stress at the time of cooling” by the value of the “elastic limit”, the value of the “shrinking stress at the time of cooling / elastic limit” was obtained.

[Gloss retention]
The technical term “gloss retention” used in the present invention means a gloss retention of 2000 hours of a weather resistance test measured by the following measurement method.
"Measuring method"
(1) Add 55% methyl ethyl ketone peroxide 1.0%, 6% cobalt naphthenate 0.1% to the unsaturated polyester resin composition, stir and degas, apply a release agent, and make the thickness 3 mm The resin composition is poured onto a glass plate having a spacer to be adjusted and sealed, and then allowed to stand at room temperature for 24 hours and further cured at 120 ° C. for 120 minutes to obtain a cast plate having a thickness of about 3 mm.

(2) A test piece of 75 mm × 70 mm was cut out from the casting plate thus obtained to obtain a weather resistance test piece. Using this test piece, an accelerated weathering test was conducted for 2000 hours using a sunshine weatherometer based on ISO standards (ISO 4892-4: a test method based on 1994 open frame carbon arc lamp).
(3) The test piece after 2000 hours was measured on the surface (test surface) according to JIS Z 8741-1997 (ISO 2813: 1994), and the specular gloss was measured at an incident angle of 60 degrees. The gloss retention was determined by the following (formula).
Gloss retention rate = (specular gloss after weathering test / specular gloss before weathering test) × 100

[Color difference]
The technical term “color difference” used in the present invention uses the display method defined in JIS Z 8730-1995 and is represented by “ΔE ^* ab”, and is weather resistance measured by the following measurement method. It represents the degree of yellowing after 2000 hours of testing.
"Measuring method"
(1) It measured using the same test piece of thickness 3mm used by the measurement of the gloss retention in the said weather resistance acceleration | stimulation test. That is, the object color on the surface of the test piece is measured by the method prescribed in JIS Z 8722, and the “color difference” according to the L ^* a ^* b ^* color system is calculated by the following (formula 2).
ΔE ^* ab = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2 (Formula 2)

(2) “ΔE ^* ab: L ^* a ^* b ^* color difference due to color system.
ΔL ^* , Δa ^* , Δb ^* : L ^* a ^* b ^* defined in JIS Z 8279. Difference between CIE 1976 lightness L ^* and color coordinates a ^* , b ^* in two color bodies in the color system.
ΔE ^* ab is abbreviated and displayed as “ΔE”, and this is set as a “color difference” value.
(3) Since the test piece is transparent, place a white plate that does not transmit light on the opposite side of the measurement surface. In such measurement, since the color difference greatly depends on the film thickness, it is necessary to correct the film thickness according to the LAMBERT law when comparing test pieces having a thickness other than 3 mm. A higher ΔE value indicates more severe discoloration such as yellowing.

  The unsaturated polyester (A) used in the present invention is derived from a dibasic acid component and a polyhydric alcohol component. (1) An alicyclic saturated dibasic acid and an aliphatic unsaturated dibasic acid are used in combination as a preferred dibasic acid component, and (2) (a) a symmetric glycol as a preferred polyhydric alcohol component; b) A glycol having no side chain and at least one glycol selected from asymmetric glycols having a side chain are used in combination.

Preferred examples of the alicyclic saturated dibasic acid used in the present invention include, for example, hexahydrophthalic anhydride, hexahydrophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, methylhexahydrophthal Examples include acid, het acid, and 1,1-cyclobutanedicarboxylic acid. These compounds may be used alone or in combination of two or more.

Preferred examples of the aliphatic unsaturated dibasic acid used in the present invention include α, β-unsaturated dibasic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, and aconitic acid. And β, γ-unsaturated dibasic acids such as dihydromuconic acid. These compounds may be used alone or in combination of two or more. Among these, maleic acid, maleic anhydride, and fumaric acid are particularly preferable.

In addition to the above dibasic acid component, aliphatic saturated dibasic acid, aromatic saturated dibasic acid and other dibasic acids are used in combination with 20 mol% or less of the total amount of the acid component, as long as the effects of the present invention are not impaired. May be. Examples of the aliphatic saturated dibasic acid include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, glutaric acid, pimelic acid, suberic acid, dodecanedioic acid and the like.

Examples of the aromatic saturated dibasic acid include phthalic anhydride, isophthalic acid, terephthalic acid, trimet acid, pyromellitic acid, and the like. These compounds may be used alone or in combination of two or more. In the present invention, an aromatic acid component such as an aromatic monobasic acid, an aromatic saturated dibasic acid or an anhydride thereof is preferably not used in combination, but a range satisfying the color difference of the weather resistance intended by the present invention. You may use together. When an aromatic acid component is used in combination, it is preferable to lower the resin viscosity by using an aliphatic saturated dibasic acid such as adipic acid.

  The polyhydric alcohol component (2) used in the present invention is preferably (a) a symmetric glycol selected from an aliphatic glycol or an alicyclic glycol, and (b) a glycol having no side chain and a side chain. It consists of a combination with at least one glycol selected from asymmetric glycols having

Examples of the symmetric glycol (a) used in the present invention include neopentyl glycol, hydrogenated bisphenol A, hydrogenated bisphenol F, 2,2-diethyl-1,3-propanediol, and 1,4-cyclohexanedi. Examples thereof include methanol and 1,4-cyclohexanediol. Neopentyl glycol is preferable.

Further, the glycol (b) having no side chain is preferably one having 2 or more carbon atoms in the straight chain portion and having hydroxyl groups at both ends. More preferably, a linear glycol having hydroxyl groups at both ends of 3 to 10, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol and the like.

In addition, the asymmetric glycol (b) having a side chain is preferably a glycol having an odd number of carbon atoms in the main chain and one short alkyl group as the side chain or two different short alkyl groups. And glycols that lower the resin viscosity, such as 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,4-butanediol, 2-ethyl-1,4-butane Examples include diol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, and 3-methyl-1,5-heptanediol.

In addition to the polyhydric alcohol component, other polyhydric alcohol components can be used in combination as long as the effects of the present invention are not impaired. Examples of the polyhydric alcohol component (2) that can be used in combination include adducts of hydrogenated bisphenol A with an alkylene oxide such as ethylene oxide, propylene oxide, or butylene oxide, and ethylene glycol carbonate. And trihydric alcohols such as monohydric alcohol, glycerin and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol. These polyhydric alcohol components are preferably 10 mol% or less of the total amount of polyhydric alcohol. In order to obtain a resin composition excellent in yellowing resistance, an aromatic glycol compound that causes yellowing, that is, an aromatic glycol that forms a chromophore by a photoreaction or an ether bond causes a deterioration reaction by light. It is preferable not to use an ether group-containing glycol which easily proceeds.

Examples of the asymmetric glycol (b) having a side chain used in the present invention include 1,3-propanediol, 2-methyl-1,3-propanediol, and 2-butyl-2-ethyl-1,3-propanediol. As described above, when glycol having an odd number of carbon atoms is used, there are advantages that the resin viscosity can be lowered, the content of the polymerizable unsaturated monomer can be reduced, and the viscosity of the resulting composition can be lowered.

In addition, monovalent alcohols such as benzyl alcohol, 2-ethylhexyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, and stearyl alcohol are used for blocking the terminal carboxyl group of unsaturated polyester (A). Is possible.

The unsaturated polyester (A) used in the present invention is obtained by subjecting the above dibasic acid component (1) and the above polyhydric alcohol component (2) mentioned as preferred examples to a condensation reaction by a known method. Is. The molar ratio of the dibasic acid component (1) and the polyhydric alcohol component (2) is preferably (1) / (2) = 0.9 to 1.3.

The following blending examples can be given as blending examples of the preferred unsaturated polyester (A) used in the present invention.

Formulation Example 1:
Dibasic acid component (1): alicyclic saturated dibasic acid 30 to 65 mol%, aliphatic unsaturated dibasic acid 35 to 70 mol%,
Polyhydric alcohol component (2): composed of 60 to 80 mol% of the symmetric glycol (a) and 20 to 40 mol% of the glycol (b) having no side chain.

Formulation Example 2:
Dibasic acid component (1): alicyclic saturated dibasic acid 30 to 65 mol%,
35-70 mol% aliphatic unsaturated dibasic acid,
Polyhydric alcohol component (2): composed of 40 to 80 mol% of the symmetric glycol (a) and 20 to 60 mol% of the asymmetric glycol (b) having a side chain.

Formulation Example 3:
Dibasic acid component (1): alicyclic saturated dibasic acid 30 to 65 mol%, aliphatic unsaturated dibasic acid 35 to 70 mol%,
Polyhydric alcohol component (2): 60 to 80 mol% of the symmetric glycol (a), 10 to 35 mol% of the glycol (b) having no side chain and 5 to 10 mol of the asymmetric glycol (b) having a side chain %.

  The unsaturated polyester (A) used in the present invention contains an unsaturated polyester acrylate obtained by reacting a carboxyl group at the molecular end with an unsaturated epoxy compound such as glycidyl methacrylate. Furthermore, a urethane bond-containing unsaturated polyester acrylate obtained by reacting a hydroxyl group at the molecular end with an unsaturated compound having an isocyanate group and an unsaturated group, or a hydroxyl group at the molecular end and an unsaturated monobasic acid or acid anhydride thereof The unsaturated polyester acrylate obtained by reacting with is also included.

  The polymerizable unsaturated monomer (B) used in the present invention is preferably a styrene monomer and / or an acrylic monomer, and if necessary, at least one polymerizable monomer in another molecule. An unsaturated monomer having a double bond can be used in combination. Examples of the styrene monomer include styrene, p-methyl styrene, α-methyl styrene, t-butyl styrene, vinyl toluene, divinyl benzene, chlorostyrene, dichlorostyrene, and the like. These compounds may be used alone or in combination of two or more.

  Examples of the acrylic monomer and (meth) acrylic monomer include methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and propyl methacrylate. , Isopropyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, dicyclopentenyloxyethyl methacrylate, t-butylcyclohexyl methacrylate, methacrylic acid, etc. Methacrylic acid and its esters, methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, isopropyl acrylate, 2-ethylhexyl acrylate, Lauryl acrylate, 2-hydroxyethyl acrylate, cyclohexyl acrylate, isobornyl acrylate, dicyclopentenyloxyethyl acrylate, t-butylcyclohexyl acrylate, acrylic acid and its esters, (meth) acrylamide, methoxydiethylene glycol (Meth) acrylate, methoxytetraethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, β- (meth) acryloyloxyethyl hydrogen phthalate, β- (meth) acryloyloxypropyl hydrogen phthalate, β- (meth) acryloyl Oxyethyl hydrogen succinate, nonylphenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) a Relate, phenoxy polyethylene glycol (meth) acrylate, methoxy triethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, butoxy diethylene glycol (meth) acrylate, nonyl phenoxyethyl (meth) acrylate. These compounds may be used alone or in combination of two or more.

  Also, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, propylene glycol Di (meth) acrylate, 1,4-butylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane Tri (meth) acrylate, trimethylolethane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolethane tri (meth) acrylate, tetramethylo Methanetetra (meth) acrylate, 2,2-bis [4-((meth) acryloxyethoxy) phenyl] propane, pentaerythritol tri (meth) acrylate, cipentaerythritol hexa (meth) acrylate, oligoester (meth) acrylate , Urethane (meth) acrylate oligomer, (meth) acryl-modified epoxy oligomer, epoxy-modified acrylic urethane oligomer, (meth) acrylate oligomer, and the like. These compounds may be used alone or in combination of two or more.

  Examples of other polymerizable unsaturated monomers used in addition to the polymerizable unsaturated monomer (B) include monomethyl fumarate, dimethyl fumarate, monomethyl maleate, dimethyl maleate, monoethyl fumarate, and fumarate. Diethyl acid, monoethyl maleate, diethyl maleate, monopropyl fumarate, dipropyl fumarate, monopropyl maleate, dipropyl maleate, monobutyl fumarate, dibutyl fumarate, monooctyl fumarate, dioctyl fumarate, monomethyl itaconate, Examples include α, β-unsaturated polybasic acid alkyl esters such as dimethyl itaconate, diethyl itaconate, monoethyl itaconate, monobutyl itaconate, dibutyl itaconate, monopropyl itaconate, dipropyl itaconate, and diallyl phthalate. These compounds may be used alone or in combination of two or more.

  The amount of the polymerizable unsaturated monomer (B) used in the present invention is not particularly limited as long as the effect of the present invention is achieved, and is usually 60% by weight or less. When using a monomer to lower its volatility and improve yellowing resistance, the weight of the styrenic monomer as unsaturated polyester (A) / polymerizable unsaturated monomer (B) In the proportions, 60 to 95% by weight of unsaturated polyester (A) and 5 to 40% by weight of styrene monomer (B) are preferable. More preferably, the amount is 70 to 85% by weight of unsaturated polyester (A) and 30 to 15% by weight of styrene monomer (B). If it is this range, it has a good influence on the gloss retention of the cured resin. Preferably, a styrene monomer and an acrylic monomer are used in combination. The weight ratio in this case is preferably unsaturated polyester (A), styrene monomer, acrylic monomer and mixture (B) = 40 to 95:60 to 5 (wt%). The mixing ratio of the styrene monomer and the acrylic monomer is preferably 0 to 50:50 to 100 (% by weight).

The viscosity of the unsaturated polyester resin composition of the present invention is adjusted to 4.5 to 0.2 Pa · s by blending the unsaturated polyester (A) and the polymerizable unsaturated monomer (B). Are preferred.

The number average molecular weight (Mn) of the unsaturated polyester (A) used in the present invention is preferably in the range of 1200 to 5000. When the number average molecular weight is less than 1200, the mechanical strength of the cured resin is low, and when it exceeds 5000, the viscosity of the unsaturated polyester resin composition becomes high, which is not preferable.
In addition, the glass transition temperature (Tg) of the cured resin obtained from the polyester resin composition of the present invention is preferably 5 ° C to 130 ° C.

  The unsaturated polyester resin composition of the present invention may further contain an ultraviolet absorber, an ultraviolet stabilizer and the like. Examples of such ultraviolet absorbers include benzophenone-based, benzotriazole-based, and cyanoacrylate-based compounds, and examples of ultraviolet stabilizer include hindered amine-based compounds. These forms are not particularly limited, and they may have reactivity capable of polymerization or reactivity capable of esterification, and are appropriately selected and used.

  Moreover, you may mix | blend various organic peroxide as a hardening | curing agent with the unsaturated polyester resin composition of this invention. Examples of the organic peroxide include methyl ethyl ketone peroxide, benzoyl peroxide, acetylacetone peroxide, bis-4-t-butylcyclohexanedicarbonate, t-butylperoxy-2-ethylhexanate, and the like. A compound may be individual or may use 2 or more types together.

  The unsaturated polyester resin composition of the present invention may contain a polymerization inhibitor, a curing accelerator, a dye, a pigment, a plasticizer, a paraffin-based wax or the like as necessary. Examples of such a polymerization inhibitor include hydroquinone, pyrocatechol, and 2,6-t-butylparacresol. Examples of the curing accelerator include metal soaps such as cobalt naphthenate and cobalt octenoate, Examples include quaternary ammonium salts such as dimethylbenzylammonium chloride, β-diketones such as acetylacetone, amines such as dimethylaniline, N-ethyl-metatoluidine, and triethanolamine. Furthermore, known thixotropic agents such as silica powder and asbestos powder, various additives such as fillers, stabilizers, antifoaming agents and leveling agents, and polymethacrylic acid resin (PMMA) as long as the performance of gloss retention is not impaired. Or a commercially available macromonomer (AA-6, AA-10 Toagosei Co., Ltd.) can be blended.

  The pigment used in the composition of the present invention is preferably one used for coloring, for example, titanium white, bengara, condensed azo red, titanium yellow, cobalt blue, quinacridone red, carbon black, iron black, ultramarine green. , Blue, perinone, bitumen, isoindolinone, chrome green, cyanine blue, green and the like. A substance that is excellent in UV stability and does not hinder the curing of the polyester resin is selected and blended according to the color tone. These coloring pigments can be directly mixed and dispersed in a polyester resin or added as a color toner previously kneaded with a saturated or unsaturated polyester solid. The added amount of the pigment is preferably 0.1 to 50 parts by weight of the pigment with respect to 100 parts by weight of the dissolved unsaturated polyester and polymerizable unsaturated monomer.

  Examples of the filler used in the composition of the present invention include calcium carbonate, talc, mica, clay, silica powder, colloidal silica, asbestos powder, barium sulfate, aluminum hydroxide, glass powder, alumina powder, meteorite powder, Examples thereof include glass beads and crushed sand. These fillers can be blended with the composition of the present invention and used as putty, sealing material or coating material. It is also effective as a material for impregnating and reinforcing cloth and kraft paper.

  A fiber reinforcing material may be added to the unsaturated polyester resin composition of the present invention. Examples of the reinforcing material include glass fiber (chopped strand mat, glass roving cloth, etc.), carbon fiber, and organic fiber (vinylon, polyester). , Phenol, etc.), metal fibers, etc., and preferably 10 to 70% by weight in the composition can be used as a fiber reinforced plastic (FRP).

  As a cured product of the conventional unsaturated polyester resin composition, a product having a gloss retention of 60% or more in the weather resistance test and a color difference (ΔE) of 20 or less cannot be obtained. On the other hand, the unsaturated polyester resin composition of the present invention, as shown in the examples described later, has a cured product having a "shrinkage stress during cooling" of 17 MPa or less, preferably 15 MPa or less, and "shrinkage during cooling" By setting the “stress / elastic limit” to 1 or less, preferably 0.05 to 0.85, a cured resin product excellent in gloss retention and yellowing resistance can be obtained. The cured product obtained by the resin composition of the present invention has a physical property that delays the photodegradation reaction and can withstand repeated stress caused by a temperature difference caused by seasonal fluctuations day and night. Therefore, the weather resistance test of the sunshine weatherometer is 2000 hours. The gloss retention afterwards is 60% or more, preferably 70% or more, and the color difference (ΔE) is 20 or less, preferably 16 or less.

  The use of the unsaturated polyester resin composition of the present invention is particularly preferably useful as a coating material, that is, a lining material, a paint or a gel coating material, and when a fiber reinforcing material and / or a filler is added and mixed. Can also be used as a molding material such as SMC and BMC. In the present invention, the fiber reinforced plastic molded article in which the surface layer is formed with the gel coat material comprising the unsaturated polyester resin composition of the present invention on the surface of the fiber reinforced plastic molded article, weather resistance, yellowing resistance, surface gloss rate An excellent molded product can be provided. Examples of the fiber-reinforced plastic molded article of the present invention include a bathtub, a unit bath, a wash basin, kitchenware, a boat, a fishing boat, a tank, a panel, a vehicle member, a housing member, a chair, a desk, and an automobile member.

The coating material of the present invention is obtained by adding a curing agent and a curing accelerator to the unsaturated polyester resin composition of the present invention, and if necessary, contains a filler, a pigment, a wax, an ultraviolet absorber, and an ultraviolet stabilizer. Is. Moreover, the gel coat material of the present invention is obtained by adding a curing agent and a curing accelerator to the unsaturated polyester resin composition of the present invention, and if necessary, contains a pigment, an ultraviolet absorber, and an ultraviolet stabilizer. .

The FRP molded product of the present invention is formed by forming a gel coat layer on the mold surface with a gel coat material comprising the unsaturated polyester resin composition of the present invention, and forming a back layer thereon with a molding material such as SMC or BMC. It is formed by.

  Other uses of the unsaturated polyester resin composition of the present invention are used as a sealing material, putty, cast article, and resin concrete. In such a case, an additive such as a flame retardant may be further added as necessary.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. Also, “part” in the text indicates the weight part.

Example 1 Production of Unsaturated Polyester Composition A 2 L four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser was 366 parts neopentyl glycol, 88 parts ethylene glycol, 2 -88 parts of butyl-2-ethyl-1,3-propanediol, 462 parts of hexahydrophthalic anhydride, and 232 parts of fumaric acid were charged, the temperature was raised to 205 ° C while blowing nitrogen gas, and after reaction for 14 hours, styrene monomer 468 And 0.12 part of hydroquinone were added to obtain an unsaturated polyester resin composition having a nonvolatile content of 70% and an acid value of 12. The cured product of such a composition had a shrinkage stress during cooling of 1.6 MPa and a shrinkage stress during cooling / elastic limit of 0.14. According to the following weather resistance test, the gloss retention was 75% and the color difference was 8.9.

Example 2 Production of Unsaturated Polyester Composition In a 2 L four-necked flask similar to Example 1, 457 parts neopentyl glycol, 51 parts 1,3-propanediol, 2-butyl-2-ethyl-1,3- 70 parts of propanediol, 462 parts of hexahydrophthalic anhydride and 232 parts of fumaric acid were charged, the temperature was raised to 210 ° C., the esterification reaction was carried out, and after 12 hours of reaction, 483 parts of styrene monomer and 0.13 part of hydroquinone were added, An unsaturated polyester resin composition having a nonvolatile content of 70% and an acid value of 9 was obtained. 100 parts of this unsaturated polyester resin, 0.5 part of Tinuvin 400 (UV absorber manufactured by Ciba Specialty Chemicals Co., Ltd.), 0.4 part of Tinuvin 123 (UV absorber manufactured by Ciba Specialty Chemicals Co., Ltd.), 0.1 part of LA-82 (Asahi Denka Kogyo Co., Ltd. UV absorber) was added to obtain an unsaturated polyester resin composition. The cured product of such a composition had a shrinkage stress during cooling of 7.3 MPa and a shrinkage stress during cooling / elastic limit of 0.31. As a result of the following weather resistance test, the gloss retention was 95% and the color difference was 3.1.

Example 3 Production of Unsaturated Polyester Resin Composition In a 2 L four-necked flask similar to Example 1, 417 parts neopentyl glycol, 152 parts 1,3-propanediol, 308 parts hexahydrophthalic anhydride, 464 fumaric acid The temperature was raised to 210 ° C., the esterification reaction was carried out, and after 14 hours of reaction, 579 parts of styrene monomer, 193 parts of methyl methacrylate and 0.12 part of hydroquinone were added, the non-volatile content was 60%, the acid value was 5, and the viscosity was An unsaturated polyester resin composition of 0.6 Pa · s was obtained. The cured product of this unsaturated polyester resin composition had a shrinkage stress during cooling of 7.9 MPa and a shrinkage stress during cooling / elastic limit of 0.71. As a result of the following weather resistance test, the gloss retention was 79% and the color difference was 13.

Example 4 Production of Unsaturated Polyester Composition Neopentyl glycol 335.3 parts, 1, 2-into a 2 L 4-neck flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser While charging 73.5 parts of propylene glycol, 90 parts of 2,2-butyl-2-ethyl-1,3-propanediol, 433.4 parts of 1,4-cyclohexanedicarboxylic acid, and 209 parts of fumaric acid, while blowing nitrogen gas After raising the temperature to 205 ° C. and reacting for 14 hours, 422 parts of styrene monomer and 0.12 part of hydroquinone were added to obtain an unsaturated polyester resin composition having a nonvolatile content of 70% and an acid value of 12. Such a composition was further added with 758.1 parts of neopentyl glycol dimethacrylate as a polymerizable unsaturated monomer to obtain an unsaturated polyester resin composition. The cured product of such a composition had a shrinkage stress during cooling of 12.4 MPa and a ratio of shrinkage stress during cooling / elastic limit of 0.67. As a result of the following weather resistance test, the gloss retention was 89% and the color difference was 11.4.

(Example 5) Production of unsaturated polyester composition In the same manner as in Example 1, 229 parts of neopentyl glycol, 297 parts of 2-methyl-1,3-propanediol, 308 parts of hexahydrophthalic anhydride, fumaric acid were added to a 2 L flask. 348 parts are charged, the temperature is raised to 210 ° C., an esterification reaction is carried out, and after reaction for 12 hours, 445 parts of styrene monomer and 0.12 part of hydroquinone are added, and an unsaturated polyester resin composition having a nonvolatile content of 70% and an acid value of 12 I got a thing. 100 parts of this unsaturated polyester resin, 0.5 part of Tinuvin 400 (UV absorber manufactured by Ciba Specialty Chemicals Co., Ltd.), 0.4 part of Tinuvin 123 (UV absorber manufactured by Ciba Specialty Chemicals Co., Ltd.), 0.1 part of LA-82 (Asahi Denka Kogyo Co., Ltd. UV absorber) was added to obtain an unsaturated polyester resin composition. The cured product of such a composition had a shrinkage stress upon cooling of 10.1 MPa and a ratio of shrinkage stress upon cooling / elastic limit of 0.45. As a result of the following weather resistance test, the gloss retention was 85% and the color difference was 13.7.

Example 6 Production of Unsaturated Polyester Composition In a 2 L four-necked flask similar to Example 1, 458 parts neopentyl glycol, 99 parts 2-methyl-1,3-propanediol, 308 parts hexahydrophthalic anhydride Then, 294 parts of maleic anhydride was added, the temperature was raised to 210 ° C., an esterification reaction was carried out, and after reaction for 14 hours, 486 parts of styrene monomer and 0.11 part of hydroquinone were added, and a non-volatile content of 68% and an acid value of 14 were obtained. A saturated polyester resin composition was obtained. The cured product of such a composition had a shrinkage stress during cooling of 7.4 MPa and a ratio of shrinkage stress during cooling / elastic limit of 0.31. As a result of the following weather resistance test, the gloss retention was 78% and the color difference was 11.4.

Example 7 Production of Unsaturated Polyester Composition In a 2 L four-necked flask similar to Example 1, 458 parts neopentyl glycol, 84 parts 1,3-propanediol, 462 parts hexahydrophthalic anhydride, 232 fumaric acid Part of the mixture, heated to 210 ° C., subjected to esterification reaction, and after reaction for 14 hours, 522 parts of styrene monomer and 0.12 part of hydroquinone were added, and an unsaturated polyester resin composition having a nonvolatile content of 68% and an acid value of 11 Got. The cured product of such a composition had a shrinkage stress during cooling of 9.1 MPa and a ratio of shrinkage stress during cooling / elastic limit of 0.55. As a result of the following weather resistance test, the gloss retention was 73% and the color difference was 14.2.

Example 8 Production of Unsaturated Polyester Composition 458 parts of neopentyl glycol, 2-methyl-1, in a 2 L 4-neck flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser 99 parts of 3-propanediol, 308 parts of hexahydrophthalic anhydride and 348 parts of fumaric acid were added, the temperature was raised to 210 ° C., the esterification reaction was carried out, and after 14 hours of reaction, 503 parts of styrene monomer and 0.11 part of hydroquinone were added. In addition, an unsaturated polyester resin composition having a nonvolatile content of 68% and an acid value of 12 was obtained. The cured product of such a composition had a shrinkage stress upon cooling of 11.7 MPa and a ratio of shrinkage stress upon cooling / elastic limit of 0.55. As a result of the following weather resistance test, the gloss retention was 67% and the color difference was 14.5.

Example 9 Production of Unsaturated Polyester Composition As in Example 1, 278 parts neopentyl glycol, 90 parts 2-methyl-1,3-propanediol, 111 parts isophthalic acid, 44 parts adipic acid in a 2 L flask Then, 103 parts of hexahydrophthalic anhydride and 197 parts of fumaric acid were added, the temperature was raised to 210 ° C., the esterification reaction was carried out, and after 12 hours of reaction, 279 parts of styrene monomer and 0.05 part of hydroquinone were added, and the nonvolatile content was 70%. An unsaturated polyester resin composition having an acid value of 12 was obtained. The cured product of such a composition had a shrinkage stress upon cooling of 6 MPa and a ratio of shrinkage stress upon cooling / elastic limit of 0.25. As a result of the following weather resistance test, the gloss retention was 66% and the color difference was 13.7.

(Comparative Example 1) Production of unsaturated polyester composition In the same manner as in Example 1, 416 parts of neopentyl glycol, 152 parts of 1,2-propylene glycol, 332 parts of isophthalic acid and 464 parts of fumaric acid were charged and the temperature was raised to 210 ° C. The mixture was warmed and subjected to an esterification reaction. After 14 hours of reaction, 939 parts of styrene monomer and 0.12 part of hydroquinone were added to obtain an unsaturated polyester resin composition having a nonvolatile content of 55% and an acid value of 5. The cured product of such a composition had a shrinkage stress during cooling of 29.6 MPa and a ratio of shrinkage stress during cooling / elastic limit ratio of 1.31. As a result of the following weather resistance test, the gloss retention (1500 hours) was 60%, and the color difference was 20.4.

Comparative Example 2 Production of Unsaturated Polyester Composition As in Example 1, 208 parts of neopentyl glycol, 76 parts of 1,2-propylene glycol, 154 parts of hexahydrophthalic anhydride, and 196 parts of maleic anhydride were charged. The temperature was raised to 210 ° C., an esterification reaction was performed, and after the reaction for 14 hours, 410 parts of styrene monomer and 0.06 part of hydroquinone were added to obtain an unsaturated polyester resin composition having a nonvolatile content of 60% and an acid value of 5. . The cured product of such a composition had a shrinkage stress during cooling of 20.6 MPa and a ratio of shrinkage stress during cooling / elastic limit of 0.72. Further, as a result of the following weather resistance test, the gloss retention (1500 hours) was 40% and the color difference was 15.

(Comparative Example 3) Production of unsaturated polyester composition In the same manner as in Example 1, 406 parts of 2-methyl-1,3-propanediol, 444 parts of phthalic anhydride and 147 parts of maleic anhydride were added and the temperature was raised to 210 ° C. The mixture was warmed and subjected to an esterification reaction. After 14 hours of reaction, 610.9 parts of styrene monomer and 0.06 part of hydroquinone were added to obtain an unsaturated polyester resin composition having a nonvolatile content of 60% and an acid value of 7. As a result of the following weather resistance test, the cured product of this composition had a gloss retention rate (1500 hours test) of 29%, so the shrinkage stress during cooling was not measured.

(Test example)
The following tests were conducted using the unsaturated polyester resin composition. The results are summarized in Tables 1 and 2.

~ Shrinking stress during temperature drop ~
The shrinkage stress during cooling at 70 ° C. to 20 ° C. was measured by the measurement method described above using the resin compositions of the above examples and comparative examples.

-Weather resistance test with sunshine weatherometer-
1) Preparation of test plate 55% methyl ethyl ketone peroxide 1.0% and 6% cobalt naphthenate 0.1% were added to the unsaturated polyester resin compositions obtained in Examples and Comparative Examples, and the mixture was stirred and degassed. And used as a resin composition. A release agent (Flycoat FRP, F-REKOTE) is applied to the glass plate, and the resin composition is poured onto a glass plate that has been sealed with a spacer for adjusting the thickness, and then left at room temperature for 24 hours. It was further cured for 120 minutes to obtain a cast test plate having a thickness of about 3 mm.

2) Weather resistance test A 75 mm × 70 mm test piece was cut out from the test plate obtained in Method 1) to prepare a weather resistance test piece. As a weather resistance test method, an accelerated weather resistance test was performed using a sunshine weatherometer (WEL-SUN-HCH-B type manufactured by Suga Test Instruments Co., Ltd.).
Test conditions:
Temperature 63 ± 3 ° C Cycle 18 minutes in 120 minutes Rain time 2000 hours
The test pieces were checked every 250 hours, and the test was stopped for those with a significant gloss reduction.

3) Evaluation of weather resistance The gloss and color difference of the test piece after the test were measured. As a measuring instrument, a gloss meter “GM26D type manufactured by Murakami Color Research Laboratory Co., Ltd.” was used. The measurement angle was 60 degrees. The gloss retention was determined by “(specular gloss after test / specular gloss before test) × 100”.
The color difference was measured with a floodlight pipe and a sample stage 30φ using Nippon Denshoku Industries Co., Ltd. Z1001DP, and the ΔE value was used as the “color difference value”. Larger values indicate more severe yellowing.

~ Measurement of elastic limit ~
The elastic limit was measured for the resin compositions of the above Examples and Comparative Examples by the measurement method described above.

(Manufacture of fiber-reinforced plastic molded products)
Moreover, in order to confirm the weather resistance of the FRP molded product which uses the unsaturated polyester resin composition of this invention as a surface layer, the gel coat laminated board was produced with the method shown below.
First, a release agent (trade name Bon Lease, manufactured by KOSHIN CHEMICAL) was applied to a glass plate, and then 55% methyl ethyl ketone peroxide 1.0% and 0.6% naphthene were added to 100 parts of each resin composition of Examples and Comparative Examples. After adding 5 parts of cobalt acid and stirring, it was spray-coated on a glass plate, then allowed to stand at room temperature for 1 hour, and further cured at 60 ° C. for 30 minutes. Next, a glass chop strand mat (weight: 450 g / m ² , (M)), a glass roving cloth (570 g / m ² , (R)) and a laminating resin (Dainippon Ink & Chemicals, Inc., unsaturated) (M) + (R) + (M) glass fiber reinforcement was laminated using a polyester resin, trade name Polylite FH-286, and molded at once so as to overlap at the L-shaped corner. In this case, 2 parts of 0.6% cobalt naphthenate and 1.0 part of 55% methyl ethyl ketone peroxide were used as the laminating resin. And after leaving at room temperature for 18 hours, the FRP molded product was peeled off from the glass plate to obtain a test plate. A test piece of 50 mm × 70 mm was cut out from this test plate to prepare a weather resistance test piece. As a weather resistance test method, a sunshine weatherometer (WEL-SUN-HCH-B type manufactured by Suga Test Instruments Co., Ltd.) was used in the same manner as described above.

Test conditions:
Temperature: 63 ± 3 ° C, Cycle: 2000hr with 18min rain time in 120min
In addition, it checked visually every test time 250hr, and the test was stopped when glossiness fell remarkably. The test results are shown in Table 3.
(Weather resistance evaluation)
For the evaluation, the degree of surface whitening was visually observed.
Evaluation: ◎: No whitening ○: Almost no whitening ×: Whitening

Claims (5)

An unsaturated polyester resin composition comprising an unsaturated polyester (A) and a polymerizable unsaturated monomer (B) which is a styrene monomer and / or an acrylic monomer, and the polymerization The amount of the unsaturated unsaturated monomer (B) is in the range of 30 to 40% by weight, and the unsaturated polyester (A) is derived from a dibasic acid component and a polyhydric alcohol component, (1) The dibasic acid component is composed of 30 to 65 mol% of an alicyclic saturated dibasic acid and 35 to 70 mol% of an aliphatic unsaturated dibasic acid, and (2) the polyhydric alcohol component is composed of neopentyl glycol. (A) Symmetric glycol, (b) Ethylene glycol or 1,3-propylene glycol as glycol (b1) having no side chain, the main chain having an odd number of carbon atoms, and a short chain alkyl group as the side chain One or different And a two short chain 2-butyl-2-ethyl-1,3-propanediol or 2-methyl-1,3-propanediol as asymmetric glycol (b2) having an alkyl group of at least one element selected that Consisting of glycol,
(B) the polyvalent alcohol component is the symmetric glycol (a) 60-80 mol% and a glycol having no side chain (b1) made of 20 to 40 mol%,
(B) the polyvalent what alcohol component consisting of 20 to 60 mol% asymmetric glycol (b2) having a symmetric glycol (a) 40 to 80 mol% and a side chain, or (c) the polyhydric alcohol component Is composed of 60 to 80 mol% of the symmetric glycol (a), 10 to 35 mol% of the glycol (b1) having no side chain, and 5 to 10 mol% of the asymmetric glycol (b2) having a side chain,
A coating material comprising an unsaturated polyester resin composition in which the cured product has a "shrinkage stress during cooling" of 17 MPa or less and a "shrinkage stress during cooling / elastic limit" of 1 or less. The coating material according to claim 1, wherein the gloss retention of the cured product of the unsaturated polyester resin composition is an unsaturated polyester resin composition having a glossiness of 60% or more. The coating material according to claim 1, wherein the cured polyester resin composition has a gloss retention of 60% or more and a color difference of 20 or less. It is a gel coat material, The coating | covering material in any one of Claims 1-3 characterized by the above-mentioned. Claim 1-3 fiber-reinforced plastic molded article characterized by having a surface layer comprising a cured product of the coating material according to any one.