JPS5853645B2 - Unsaturated polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel unsaturated polyester resin composition,
More specifically, the present invention relates to an unsaturated polyester resin composition with improved curing reactivity, shrinkability, flexibility, water resistance, etc.

Unsaturated polyester resin compositions consisting of unsaturated alkyds and crosslinkable vinyl monomers generally have excellent mechanical properties, electrical properties, chemical resistance, etc., and are relatively inexpensive, so they are used in paints and cast products. Widely used in fields such as , laminates, linings, decorative laminates, and sealants.

Particularly recently, it has come to be used in structural materials as a core plastic used in glass fiber reinforced plastics combined with glass fibers.

However, even with these advantages, unsaturated polyester resin compositions have drawbacks, including poor curing reactivity, particularly poor air drying properties, and high shrinkage during curing.

In other words, when an unsaturated polyester resin composition is cured in the air with peroxide, the surface in contact with the air is not sufficiently cured and becomes sticky, and the shrinkage rate during curing is large, causing internal reactions. This has become a problem, causing cracks in the molded product after curing and impairing the adhesion with glass fibers.

Therefore, various methods have already been developed to improve the air drying properties of unsaturated polyester resin compositions.

For example, a method is known in which a petroleum resin modified with an unsaturated acid ester is blended into an unsaturated polyester resin composition in order to improve air drying properties.
No. 0).

However, although this method improves air drying,
Because the compatibility between the unsaturated polyester resin composition and the modified petroleum resin is not always sufficient, the coating film becomes cloudy.
There were also problems with flexibility and water resistance.

The present inventors conducted intensive research to improve the shortcomings of the conventional technology, and found that when a specific cyclopentadiene resin is added during the synthesis of unsaturated alkyds, it not only improves air curability and shrinkage rate during curing. , water resistance of cured product,
The present invention was completed based on the discovery that flexibility and other properties were also improved.

That is, an object of the present invention is to provide an unsaturated polyester resin composition that can form a cured product with improved air drying properties and shrinkage rate during curing, as well as improved flexibility and water resistance. The object of the present invention is to use a cyclobencdiene monomer of 85 to 55% by weight and a monoolefinic unsaturated alcohol or a vinyl containing an ester bond as an unsaturated alkyd component which is one component of an unsaturated polyester resin composition. An α,β-unsaturated dibasic acid component and a polyhydric alcohol component are reacted in the presence of a cyclopentadiene resin obtained by thermal copolymerization of a monomer mixture with 15 to 45 weight monomers. This is achieved by using a modified alkyd obtained by

The cyclopentadiene resin used in the present invention contains a cyclopentadiene monomer of 85 to 55% by weight, preferably 80 to 65% by weight, and a monoolefinic unsaturated alcohol or a vinyl monomer containing an ester bond ( Hereinafter, it may be abbreviated as ester-containing monomer) 15~
A known method (e.g., thermal polymerization of a mixture of 45 weight φ, preferably 20 to 35 weight φ at 250 to 300°C for 0.5 to 20 hours in the presence or absence of an inert solvent such as benzene, toluene, or xylene) , U.S. Patent No. 26892
No. 32) with a softening point of 50 to 160°C, preferably 70 to 145°C, and a Gardner chromaticity of 12 or less.

The molecular weight and softening point of the resulting resin can be adjusted by appropriately selecting polymerization conditions such as reaction temperature, reaction time, and monomer concentration; however, as the softening point increases, the cured product tends to become brittle. On the other hand, as the temperature decreases, stickiness remains on the surface of the cured product.

Furthermore, if the amount of the cyclopentadiene monomer is too large, the compatibility with the unsaturated alkyd will be poor, and if the amount is too small, the effect of improving drying properties and shrinkage rate will be small. excluded from.

The cyclopentadiene monomer used in the polymerization includes cyclopencdiene, lower alkyl-substituted cyclopentadiene such as methyl-substituted and ethyl-substituted cyclopentadiene, and dimers thereof;
These include low-order Diels-Ander adducts such as trimers and codimers, as well as mixtures thereof, and the higher the purity, the better.

On the other hand, the comonomer copolymerizable with the cyclopentadiene monomer used in the present invention is an ester-containing monomer or a monoolefinic unsaturated alcohol.

The ester-containing monomer is a compound represented by the general formula (wherein X, Y and Z represent hydrogen or a methyl group, and R represents an alkyl group having 1 to 8 carbon atoms), and its specific Examples include fatty acid esters of unsaturated alcohols such as vinyl acetate, vinyl propionate, vinyl butyrate, etc. and methyl acrylate, methyl methacrylate, methyl crotonate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate. Examples include alkyl esters of α,β-unsaturated fatty acids such as, among others, vinyl acetate is particularly preferred.

In addition, unsaturated alcohols are mono- and polyvalent monoolefinic unsaturated alcohols having 3 to 6 carbon atoms, and specific examples thereof include allyl alcohol, crotyl alcohol,
, 4-butynediol, ■.

Examples include 2-butynediol and 3-hexene-2,5-diol, among which allyl alcohol is preferred.

Other known monomers that can be copolymerized with cyclopentadiene monomers include 1,3-butadiene, styrene, and isoprene; When using a resin obtained by the above method, it has poor compatibility with unsaturated alkyds and is extremely poor in adhesion, flexibility, etc.

Further, in the present invention, instead of the cyclopentadiene resin, a derivative obtained by modifying the resin according to a known method can also be used.

Specific examples include acid-modified resins obtained by adding maleic anhydride or fumaric acid, and hydrogenated resins obtained by hydrogenation. It has the same effect as other resins.

In the present invention, a modified alkyd synthesized in the presence of such a cyclopentadiene resin is used as an unsaturated alkyd component.

This modified alkyd can be obtained by a conventional method except that the cyclopentadiene resin is an essential component. 5 at 200℃
It is obtained by a thermal reaction for about 10 hours.

At this time, the reaction between the cyclopentadiene resin and other components proceeds through esterification or transesterification of the hydroxyl groups or ester bonds present in the cyclopentadiene resin.

The α,β-unsaturated dibasic acid components used are typified by maleic acid and maleic anhydride, but are not particularly limited to these, and if desired, phthalic acid, tetrahydrophthalic acid, Other dibasic acids or anhydrides such as these anhydrides can also be used in combination.

Further, the polyhydric alcohol component is not particularly limited as long as it is commonly used, and examples thereof include ethylene glycol, propylene glycol, diethylene glycol, and the like.

The proportion of the cyclopentadiene resin used in the synthesis of the modified alkyd is in the range of 5 to 40 weight φ, preferably 10 to 30 weight φ, based on the total of the modified alkyd and the crosslinkable vinyl monomer. If the amount of the system resin is less than 5 weight φ, the effect of improving drying properties is poor, and on the other hand, if it is blended in a large amount exceeding 40 weight φ, the strength, adhesion, flexibility, etc. of the cured product will be significantly reduced, which is not preferable. do not have.

On the other hand, the crosslinkable vinyl monomer used in the present invention is, for example, ethylene, α-methylstyrene, methyl methacrylate, etc., and these vinyl monomers usually account for 20 to 50 weight φ of the total amount with the unsaturated alkyd component.
used within the range.

The thus obtained unsaturated polyester resin composition of the present invention can be easily cured by mixing with a radical-generating peroxide and reacting at room temperature or under heating according to a conventional method, and can be used as a curable resin in paints, cast products, etc. Widely used in fields such as laminates, linings, decorative laminates, and sealants.

Furthermore, organic metal salt dryers, organic and inorganic pigments, fillers, etc., which are commonly used in the composition of the present invention, can also be blended and used.

The present invention will be explained in more detail with reference to Examples below.

Note that all parts and parts in Examples and Reference Examples are based on weight.

Reference Example 1 A monomer mixture having the composition shown in Table 1 was thermally polymerized at 260° C. for 3 hours in the presence of a xylene solvent to obtain various cyclopentadiene resins.

Example 1 In a four-day flask, 233 parts of diethylene glycol, 98 parts of maleic anhydride, 148 parts of phthalic anhydride, and the resin (4) obtained in Reference Example 1, that is, a cyclopentadiene resin having a hydroxyl group in the molecule and a softening point of 90°C Prepare 90 parts of resin, 1
The mixture was refluxed at 60° C. for 3 hours under a nitrogen stream, then the temperature was further raised to 200° C., and water produced was removed under reduced pressure to proceed with esterification until the acid value reached 45.

Thereafter, the mixture was cooled to 60° C., and 234 parts of styrene containing 0.2 parts of hydroquinone was added to prepare an unsaturated polyester resin composition.

Next, the curing reactivity when using this composition for casting was measured at 80°C using benzoyl peroxide as a catalyst in accordance with JIS K-6901, and as a guideline for the shrinkage of the cured product, the curing reactivity was measured at 80°C. After curing for 1 hour, the density was measured.

For comparison, a case of synthesis without adding cyclopentadiene resin was tested in the same manner and its performance was evaluated.

The results are shown in Table 2. From these results, it can be seen that in the case of the examples of the present invention, the curing speed is increased, the exothermic temperature is decreased, and the shrinkability is also improved.

Example 2 167 parts of propylene glycol, 98 parts of maleic anhydride, and 148 parts of phthalic anhydride were placed in a four-hole flask,
Reflux at 0°C for 3 hours under a nitrogen stream to give an acid value of 100 to 15.
After esterification until the acid value reaches 0, 90 parts of the various resins shown in Table 1 are added, the temperature is further raised to 200°C, and the water and unreacted propylene glycol produced are removed by reducing the pressure.The esterification is continued until the acid value becomes 50 or less. The modified unsaturated alkyd was synthesized.

Thereafter, the mixture was cooled to 60° C., and 300 parts of styrene containing 0.2% of hydroquinone was added to prepare an unsaturated polyester resin composition.

The curing reactivity of the obtained unsaturated polyester resin composition was investigated in the same manner as in Example 1, and the physical properties of the cured product were also measured.

A sample for measuring the physical properties of the cured product was prepared by dissolving 1 part of benzoyl peroxide in 100 parts of the unsaturated polyester resin compound, pouring it into a glass frame prepared in advance, and heating it at 60°C for 15 hours and then at 110°C. React for 2 hours to make a casting plate.
It was cut to predetermined dimensions and subjected to the following tests.

The results are shown in Table 3. From this result, it was found that the composition of the present invention (
It can be seen that in Experiment Nos. 1 and 2), the curing speed was higher and the exothermic temperature was lower than in the case of no additive (Experiment No. 5).

Furthermore, looking at the physical properties of the cured product, it can be seen that the flexibility is improved without lowering the bending strength, and the water resistance is greatly improved.

Furthermore, from a comparison of the densities of the cured products, it can be seen that the shrinkage properties during curing are also improved.

On the other hand, when using resins outside the scope of the present invention as shown in the control examples (Experimental Examples 3 and 4), no improvement in curing properties was observed, and the reactivity and compatibility during the synthesis of unsaturated alkyds As a result, the cured product is opaque and has poor mechanical strength.

Claims (1)

[Scope of Claims] 1. An unsaturated polyester resin composition comprising an unsaturated alkyd and a crosslinkable vinyl monomer, wherein the unsaturated alkyd contains a cyclopentadiene monomer of 85 to 55 weight φ and a monoolefinic unsaturated alcohol. Or a novel product characterized in that it is synthesized in the presence of a cyclopentadiene resin obtained by thermal copolymerization of a monomer mixture with a vinyl monomer containing an ester bond of 15 to 45 weight φ. unsaturated polyester resin composition. 2 The softening point of cyclopentadiene resin is 50 to 160
The unsaturated polyester resin composition according to claim 1, which is 'C. 3. The unsaturated polyester resin composition according to claim 2, wherein the cyclopentadiene monomer is cyclopentadiene, methylcyclopentadiene, or a dimer, trimer, or codimer thereof. 4 Monoolefinic unsaturated alcohol has 3 to 6 carbon atoms
The unsaturated polyester resin composition according to claim 1, which has the following. 5. The unsaturated polyester resin composition according to claim 4, wherein the monoolefinic unsaturated alcohol is allyl alcohol. 6. The unsaturated polyester resin composition according to claim 1, wherein the vinyl monomer containing an ester bond is a fatty acid ester of a monoolefinic unsaturated alcohol. 1. The unsaturated polyester resin composition according to claim 1, wherein the vinyl monomer containing an ester bond is vinyl acetate.