JPH029052B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an ultraviolet curable unsaturated polyester resin composition that can provide coatings, molded articles, etc. with excellent crack resistance and surface abrasiveness. Recently, there has been a growing demand for higher performance paints that are suitable for resource and energy conservation due to social needs.
As such paints, ultraviolet curable paints are used because of their advantages such as (1) fast curing, (2) low energy costs, and (3) non-polluting properties.
For example, in wood painting, UV-curable paints obtained by adding photosensitizers to air-curable unsaturated polyester resins are used as intermediate coating paints, so-called sanding paints, which are the most commonly used paints. There is. However, when such a paint is cured by irradiation with ultraviolet rays, its surface dryness is insufficient, its abrasiveness is poor, and furthermore, when it is completely cured, it has the disadvantage that cracks occur due to the large internal distortion of the paint film. The reason for the occurrence of this crack is that, in general, in the curing mechanism, ultraviolet curing has an extremely high radical generation rate and is fast curing compared to conventional room temperature curing using peroxide and organometallic salts such as cobalt naphthenate and cobalt octenoate. This is presumed to be due to the fact that a large amount of internal distortion inevitably occurs. In particular, advances in photosensitizers and light irradiation equipment have made it possible to increase curing speeds and improve productivity, but on the other hand, the problem of cracks as described above has become an even bigger problem. Improvements are desired. In order to improve these drawbacks, the main methods used are (1) to lower the crosslinking density of the cured product to soften the coating film, and (2) to introduce a flexible skeleton into the resin molecule or the crosslinking agent. It's been coming. However, these methods not only do not sufficiently improve cracks, but also have defects that adversely affect workability, such as a decrease in the hardness and chemical resistance of the cured coating, and poor surface dryness, making polishing impossible. ing. In particular, the inventors of the present invention have found that without reducing the film properties and working properties necessary for sanding paints,
As a result of intensive research on resin compositions with excellent crack resistance and good surface abrasiveness, we discovered that unsaturated polyester resins are made by addition-reacting unsaturated polyesters containing terminal carboxyl groups with glycidyl compounds, which are unsaturated monobasic acids, and allyl ethers. By mixing with an unsaturated polyester resin containing groups,
Discovered an ultraviolet curable unsaturated polyester resin composition with excellent crack resistance and surface abrasiveness,
The present invention has now been completed. That is, the present invention provides (A) an unsaturated polyester obtained by reacting the carboxyl group of an unsaturated polyester containing a carboxyl group at the molecular end with the glycidyl group of a glycidyl ester of an unsaturated monobasic acid, and (B) unsaturated polybasic acid or its anhydride,
If necessary, a polybasic acid containing a saturated polybasic acid or its anhydride, a polyhydric alcohol, and a compound having a hydroxyl group or a glycidyl group that reacts with the carboxyl group of the polybasic acid and an allyl ether group are subjected to a condensation reaction. The present invention provides an ultraviolet curable unsaturated polyester resin composition containing an unsaturated polyester obtained by the above method and (C) a polymerizable monomer. By containing both polyester components (A) and (B), the composition of the present invention clearly shows unexpected improvements in physical properties, particularly crack resistance and surface abrasiveness, that is, a synergistic effect. The unsaturated polyester (A) constituting the composition of the present invention is composed of an acid component containing an unsaturated polybasic acid or its anhydride, optionally a saturated polyhydrochloric acid or anhydride, and a polyhydric alcohol component in an equivalent ratio. An esterified polymer obtained by reacting the acid component in excess, that is, a glycidyl ester of an unsaturated monobasic acid and a carboxyl group of an unsaturated polyester containing a carboxyl group at the molecular end (hereinafter referred to as an unsaturated glycidyl compound) It refers to an unsaturated polyester that has undergone an addition reaction with the glycidyl group of In this case, the unsaturated polyester containing carboxyl groups at the molecular ends is preferably linear with carboxyl groups at both ends, but 50% or less, preferably 75% or less of one end of both ends is a hydroxyl group. Alternative unsaturated polyesters containing terminal carboxyl groups can also be used. Further, this polyester usually has an acid value of 25 to 145. Examples of the unsaturated glycidyl compound which is a component constituting this polyester include glycidyl esters of unsaturated monobasic acids such as acrylic acid and methacrylic acid, such as glycidyl acrylate and glycidyl methacrylate. Glycidyl esters of α,β-unsaturated monobasic acids such as acrylates and glycidyl methacrylates are preferred. Further, as the unsaturated polybasic acid or its anhydride which is an essential component of the unsaturated polyester A, known and commonly used α, such as maleic acid, fumaric acid, itaconic acid, citraconic acid, methaconic acid, chlorinated maleic acid, It is selected from β-unsaturated polybasic acids or their anhydrides.
In addition, examples of saturated polybasic acids or anhydrides thereof that can be used in combination if necessary include phthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, cis-3-methyl-4-cyclohexene-cis, cis-1,2
-Dicarboxylic acid anhydride, isophthalic acid, terephthalic acid, dimethyl terephthalic acid, monochlorophthalic acid, dichlorophthalic acid, trichlorophthalic acid, hettic acid, tetrabromophthalic acid, sebacic acid, succinic acid, adipic acid, glutaric acid, pimelic acid,
Known and commonly used saturated acids such as trimellitic acid and pyromellitic acid, or their anhydrides or esters can be used. In addition, preferably cis-3-
Methyl-4-cyclohexene-cis, cis-1,
A compound having air-drying properties such as 2-dicarboxylic anhydride is preferred. The polyhydric alcohol component of the unsaturated polyester (A) includes ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-butylene glycol, 2,3 -Butylene glycol, 1,4-butylene glycol, neopentyl glycol, hexylene glycol, octyl glycol, trimethylolpropane, glycerin, pentaerythritol, ethylene oxide or propylene oxide adduct of hydroquinone, hydrogenated bisphenol A, tricyclode Known and commonly used polyhydric alcohols such as candimethylol can be mentioned. The amount of the added unsaturated glycidyl compound in the unsaturated polyester (A) is usually 5 to 30% by weight, preferably 10 to 15% by weight in the unsaturated polyester (A).
An appropriate amount is expressed as % by weight. "Allyl ether group-containing unsaturated polyester (B)" constituting the composition of the present invention refers to an acid component containing an unsaturated polybasic acid or its anhydride, optionally a saturated polybasic acid or its anhydride, and a polyhydric alcohol. It refers to a product obtained by condensing a component with a compound having a hydroxyl group or a glycidyl group that reacts with the carboxyl group of the acid component and also having an allyl ether group (hereinafter referred to as an allyl ether group-containing compound). At this time, the allyl ether group-containing compound is simultaneously mixed with other components and subjected to the reaction. Such allyl ether group-containing compounds include:
Any known and commonly used ones can be used, but representative ones include ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, triethylene glycol monoallyl ether, polyethylene glycol monoallyl ether, propylene glycol monoallyl ether, Dipropylene glycol monoallyl ether, tripropylene glycol monoallyl ether, polypropylene glycol monoallyl ether, 1,2-butylene glycol monoallyl ether, 1,3-butylene glycol monoallyl ether, hexylene glycol monoallyl ether, octylene glycol Monoallyl ether, trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether,
Allyl ether compounds of polyhydric alcohols such as glycerin monoallyl ether, glycerin diallyl ether, pentaerythritol monoallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether;
Examples include allyl ether compounds having an oxirane ring such as allyl glycidyl ether. Further, as the acid component and the polyhydric alcohol component which are the constituent components of the unsaturated polyester (B), the same ones as the acid component and the polyhydric alcohol component which constitute the unsaturated polyester (A) are used. In addition, monohydric alcohols, dicyclopentadiene or its derivatives, rosin or ester gums, oils and fats, etc. can also be used in combination. The amount of allyl ether group in the unsaturated polyester (B) is usually specified by the amount of the allyl ether group-containing compound used, and specifically, the amount of the allyl ether group-containing compound is 5 to 30% by weight in the unsaturated polyester (B). , preferably 8
An amount of ~25% by weight is suitable. As the above-mentioned "polymerizable monomer (C)" which is another essential component constituting the composition of the present invention, any known and commonly used monomer can be used, but representative ones include: Styrene, α-methylstyrene, vinyltoluene, chlorostyrene, acrylic acid or methacrylic acid or their alkyl esters, acrylonitrile, vinyl acetate, allyl acetate, triallyl cyanurate, triallyl isocyanurate, acrylamide, diacetone acrylamide, Examples include diallyl phthalate, among which styrene or methacrylic acid alkyl ester is preferred. Unsaturated polyester (A) in the composition of the invention
The mixing ratio of and (B) is usually the former: the latter (weight ratio)
is from 9:1 to 3:7, preferably from 8:2 to 5:5. In addition, polymerizable monomers and unsaturated polyesters
The weight ratio (solid content ratio) to the total amount of (A) and (B) is 2:
A ratio of 8 to 6:4 is appropriate. When the composition of the present invention having the structure described above is cured by ultraviolet light, a photosensitizing substance is added, and specific examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzyl, and diphenyl disulfide. Ido, tetramethyl-thiuram monosulfide, p-tert
-Butyltrichloroacetophenone, p-tert-
One or more of known and commonly used compounds such as butyldichloroacetophenone and 2,2-dimethoxy-2-phenylacetophenone can be used. Furthermore, organometallic salts such as cobalt naphthenate and cobalt octenoate can be used in combination with the composition of the present invention as an aid for improving surface drying properties.
Furthermore, the composition of the present invention may be used with other conventional unsaturated polyester resins, vinyl ester resins, vinyl urethane resins, vinyl ester urethane resins, polyisocyanates, polyepoxides, acrylic resins, alkyd resins, urea resins, etc., depending on the purpose. Resins, melamine resins, polyvinyl acetate, vinyl acetate copolymers, polydiene elastomers, saturated polyesters, saturated polyethers, nitrocellulose, cellulose derivatives such as cellulose-acetate butyrate, linseed oil, tung oil, large Natural and synthetic polymeric substances such as oils and fats such as bean oil, castor oil, epoxidized oil; calcium carbonate, talc, mica, clay, silica powder, colloidal silica, asbestos powder, barium sulfate, aluminum hydroxide, zinc stearate, titanium white,
Various fillers and pigments such as zinc white, red iron or azo pigments; hydroquinone, benzoquinone, toluhydroquinone, p-tert-butylcatechol,
A polymerization inhibitor such as 2,6-di-tert-butyl-4-methylphenol may also be added. The composition of the present invention thus obtained is suitable not only for coating wood products such as furniture and musical instruments, but also for coating various substrates including metal coatings such as metal surfers and top coats.
It can also be used for FRP molding. Next, the present invention will be explained in detail using reference examples, working examples, and comparative examples, but the present invention is not limited to these examples. In the following, all parts and percentages are based on weight unless otherwise specified. Reference Example 1 [Preparation of unsaturated polyester resin (A)] 166 g (1 mol) of isophthalic acid and 180 g (1.7 mol) of diethylene glycol were heated and dehydrated and condensed at 215°C in an inert gas stream until the acid value of the solid content was 7.
Intermediate-1 was obtained. Next, this intermediate-1
After cooling to 160℃, hydroquinone 0.02
g and 116 g (1 mol) of fumaric acid, and heated to 200°C.
The mixture was heated and reacted for 8 hours to obtain an unsaturated polyester. After that, add 162g of styrene to this polyester.
Intermediate-2 with an acid value of 59 was obtained. Then, 2-methylimidazole was added to this intermediate-2.
1.1g and glycidyl methacrylate 86g (0.6
A ring-opening addition reaction was carried out at 80° C. for 10 hours to obtain an unsaturated polyester resin having an acid value of 4 and a Gardner viscosity (hereinafter simply referred to as viscosity) XY. Hereinafter, this will be abbreviated as resin (A). Reference Example 2 [Preparation of unsaturated polyester resin (B)] 196 g (2 mol) of maleic anhydride and 159 g (1.5 mol) of diethylene glycol were subjected to dehydration condensation under heating at 200°C in an inert gas stream to determine the acid value of the solid content. An intermediate with 171 was obtained. After cooling this intermediate, 214 g (1 mol) of trimethylolpropane diallyl ether and 46 g of glycerin were added.
(0.5 mol) and 0.04 g of hydroquinone were added, followed by dehydration condensation under heating at 180° C. for 10 hours in an inert gas stream to obtain an unsaturated polyester. Thereafter, this polyester was dissolved in 162 g of styrene to obtain an unsaturated polyester resin having a viscosity of UV. Hereinafter, this will be abbreviated as resin (B). Reference Example 3 [Preparation of unsaturated polyester for comparison] 98 g (1 mol) of maleic anhydride, phthalic anhydride
148g (1 mole), propylene glycol 160g
(2.1 mol) and 0.06 g of hydroquinone were charged and subjected to dehydration condensation under heating at 200° C. for 12 hours in an inert gas stream to obtain an unsaturated polyester having an acid value of 27.2 in solid content. Styrene is added to the total amount of polyester (370g).
Add 182g and dissolve, acid value 18, viscosity ST
An unsaturated polyester resin was obtained. Hereinafter, this will be abbreviated as resin (C). Various constants of the unsaturated polyester resins (A), (B) and (C) obtained in Reference Examples 1 to 3 were measured. These results are summarized in Table 1.

〔Judgment criteria〕

◎ - Can be easily sanded with a small amount of force. 〇 - Can be sanded relatively easily. △ - Slight clogging of the paper is observed, but sanding itself is possible. - Paper is often clogged and sanding is difficult. Γ Pencil hardness: Measured according to JIS-K-5400.

[Table] As is clear from Table 2, the composition of the present invention was found to be excellent in both crack resistance and surface abrasiveness.

Claims (1)

[Scope of Claims] 1 (A) An unsaturated polyester obtained by reacting the carboxyl group of an unsaturated polyester containing a carboxyl group at the molecular end with the glycidyl group of a cricidyl ester of an unsaturated monobasic acid; (B) An unsaturated polybasic acid or its anhydride, optionally a polybasic acid containing a saturated polybasic acid or its anhydride, a polyhydric alcohol, and a hydroxyl group or glycidyl group that reacts with the carboxyl group of the polybasic acid. , and a compound having an allyl ether group, and (C) a polymerizable monomer.