JPS6031346B2 - Improved coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel styrene copolymer resin paint composition, and more specifically, to a room temperature drying paint composition containing a styrene copolymer resin in the binder, a cyclobentadiene resin is blended. The present invention relates to a novel styrene copolymer resin coating composition that has improved adhesion to substrates, acid resistance, and alkali resistance.

BACKGROUND ART Conventionally, styrene copolymer resins, such as high styrene resins in which styrene is the main component and a small amount of butadiene is copolymerized, have been widely used as binders for paints that dry at room temperature.

Styrene copolymer resin has improved impact resistance and maneuverability compared to the chlorinated rubber that has been used for a long time.
Furthermore, since there are no halogen elements in the polymer, when used on ships that undergo a welding process after painting, there will be no problem of rust caused by the formation of halides, which is why it is mainly used for coating metals. . However, this styrene copolymer resin still has the disadvantage of poor adhesion to substrates, and furthermore, has insufficient acid resistance and alkali resistance. The present inventors have attempted to improve the adhesion, acid resistance, and alkali resistance of styrene copolymer resin paints without sacrificing the characteristics of fast-axis properties, water resistance, corrosion resistance, and processability. As a result of their efforts, they discovered that it is effective to blend a specific cyclobentadiene resin into a styrene copolymer resin, and have completed the present invention.

The main object of the present invention is to provide a composition for a styrene copolymer resin coating that dries at room temperature and has improved adhesion, acid resistance, and alkali resistance.
An object of the present invention is to provide a styrene copolymer resin coating composition with excellent corrosion resistance and processability.

These objects of the present invention are to provide an i
per 10 parts by weight of styrene copolymer resin ii 5 to 10 parts by weight of cyclobentadiene resin with a softening point of 50 to 16,000 obtained by thermal polymerization, and if desired, commonly used pigments, plasticizers, solvents, This can be achieved by adding compounding agents such as stabilizers and dispersants to form a composition for a coating that dries at room temperature.

The cyclobentadiene resin used in the present invention contains 50 to 100% by weight (preferably 60 to 100% by weight) of a cyclobentadiene monomer, a diolefinic monomer copolymerizable therewith, and a monoolefinic monomer. A monomer component consisting of 50 to 0% by weight, preferably 40 to 0% by weight of a monomer or polar vinyl monomer is reacted with benzene, toluene, xylene, etc. in the absence of a non-radical catalyst such as a cationic catalyst. 20 with or without inert hydrocarbon solvent
After heating polymerization in an autoclave at 0 to 300°C, preferably 250 to 28,000°C, for 0.5 to 20 hours, preferably 1 to 1 field hour, low-boiling substances such as unreacted substances are removed by distillation or other conventional high-temperature methods. Softening point 50-160q0, preferably 8, synthesized by removal by means of molecular purification
0 to 1400C and a Gardner color number of 10 or less.

In addition, cyclobentadiene resins are hydrogenated using conventional methods to reduce the coloration of the resin and improve weather resistance and properties, and cyclobentadiene resins are added with ethylenically unsaturated carpoxyl compounds such as maleic anhydride. Modified ones can also be used as the cyclobentadiene resin in the present invention. At this time, if a resin with too low a cyclobentadiene monomer content is used, the compatibility with the styrene copolymer resin will be insufficient.
It is also inferior in performance such as paint drying properties, coating film hardness, flexibility, and water resistance, and is not preferred as a paint compounding agent.

Furthermore, if the softening point of the cyclobentadiene resin is too high, the compatibility with the styrene copolymer resin will be poor. Cyclobentadiene monomer means cyclobentadiene or its derivatives, and includes cyclobentadiene, lower alkyl-substituted cyclobentadiene such as methyl-substituted and ethyl-substituted cyclobentadiene, and dimers and trimers thereof. , lower Diels-Alder adducts such as codimers, and mixtures thereof.

Among these, cyclobentadiene exists stably as cyclobentadiene at room temperature, so cyclobentadiene and dicyclobentadiene are usually handled in exactly the same way. On the other hand, diolefinic monomers include conjugated diene compounds such as 1,3-butadiene, isoprene, and 1,3-pentadiene, as well as 1,4-pentadiene, 1,
It also refers to non-conjugated compounds such as 5-hexadezo, and monoolefinic monomers include styrene, Q
- Examples include methylstyrene, ethylene, propylene, butene, and bentene.

Further, the polar monoolefinic monomer is a vinyl monomer having a polar group, and includes organic unsaturated cyanide compounds such as acrylonitrile and methacrylonitrile, vinyl acetate,
Lower fatty acid esters of unsaturated alcohols such as vinyl propionate, allyl acetate, meta-allyl acetate, allyl propionate, and meta-allyl propionate, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, and unsaturated carboxylic acids and methyl alcohol, ethyl alcohol. , butyl alcohol, glycide, esters of lower alcohols such as ethylene glycol, unsaturated aldehydes such as acrolein and methacrolein, allyl alcohol, crotyl alcohol, 1,4-butenediol, 3-hexene-2,
It means monovalent to polyvalent unsaturated alcohols such as 5-diol, and other unsaturated ethers such as allylglucidyl ether.

On the other hand, the styrene copolymer resin used in the present invention is generally used as a binder for paint compositions that dry at room temperature, and is a copolymer of styrene or substituted styrene.

Comonomers used in the copolymerization include conjugated diolefins such as 1,3-butadiene, isoprene, and 1,3-bentadiene, acrylates such as methyl acrylate, ethyl acrylate, and butyl acrylate, methyl methacrylate, ethyl methacrylate, Examples include polar vinyl monomers such as methacrylates such as butyl methacrylate, with 1,3-butadiene being the most common. Substituted styrenes used in place of styrene include vinyltoluene and Q-methylstyrene. Forms of copolymerization of these monomers include radical polymerization, ionic polymerization,
Alternatively, there are emulsion polymerization, solution polymerization, etc., and any method may be used. However, the most important property of the styrene copolymer resin is the glass transition temperature, which must be 2000 or higher, preferably 30 to 1000°. The glass transition temperature of a copolymer varies depending on the ratio of styrene or substituted styrene to the comonomer; for example, in the case of a styrene-butadiene copolymer, in order to achieve a glass transition temperature of 2000 or higher, the ratio of styrene to the total monomers must be adjusted. is at least 7% by weight, preferably from 75 to 95% by weight. Even if other comonomers other than butadiene are used, the proportion of styrene or substituted styrene must be at least 7% by weight.
Preferably it is 75 to 95% by weight. Further, the comonomer does not necessarily have to be one component. A specific example of the styrene copolymer resin used is styrene/butadiene=
Glass transition temperature 50-9000 at 85/15 (weight ratio)
, a xylene-soluble high styrene resin having a number average molecular weight of 1 to 100,000. In the present invention, it is essential to contain a styrene copolymer resin as a component of the binder, and the content of the styrene copolymer resin is usually 3% by weight or more, preferably 70% by weight of the total binder component. Therefore, if a small amount of styrene copolymer resin is added as a modifier to a paint whose main binder is other binder components, such as natural bag oil or alkyd resin, cyclo Even if a bentadiene resin is blended, no significant improvement effect can be achieved.

In the present invention, it is necessary to add 5 to 100 parts by weight, preferably 10 to 7 parts by weight, of the cyclobentadiene resin to 100 parts by weight of the styrene copolymer resin.

If the amount of cyclobentadiene resin added is too small, the effect of improving the adhesion, acid resistance, and alkali resistance of the coating film will be small; conversely, if it is too large, the flexibility and impact resistance of the coating film will decrease. So I don't like it. In carrying out the present invention, a styrene copolymer resin and a cyclobentadiene resin are dissolved in commonly used paint solvents such as toluene, xylene, and solvent naphtha, and if desired, alkyd resin, natural bag oil, etc. Other binders like amino resin, acrylic resin etc., pigments like titanium oxide, red lead, Bengara, zinc dust, calcium carbonate, talc etc., plasticizers like dioctyl phthalate, dioctyl sebacate, chlorinated paraffin etc. A coating composition is prepared by adding stabilizers such as phenyl glycidyl ether and epoxidized soybean oil.

The composition is applied to the substrate in a conventional manner, such as by brushing, spraying, or otherwise, and is cured at room temperature or under forced drying at up to about 100°C if necessary to shorten drying time. By doing so, a film with excellent hardness, adhesion, flexibility, impact resistance, gloss, water resistance, corrosion resistance, and chemical resistance can be formed.

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

In addition, parts and percentages in the examples are based on weight unless otherwise specified. Example 1 A cyclobentadiene resin with a softening point of 125°C obtained by thermally polymerizing a monomer mixture of 75 parts of dicyclobentadiene and 25 parts of vinyl acetate at 260°C for 3 hours in the presence of a xylene solvent was used. A paint composition was prepared by blending with high styrene resin (styrene/butadiene weight ratio: 85/15, glass transition temperature: 5yo) according to the following formulation.

After thoroughly mixing this composition in a ball mill, it was applied to a degreased European steel plate using a percoater using a piano wire with a diameter of 1 side, and dried for one week in an atmosphere of 2500, 60% relative humidity to cure the coating. Create a membrane and evaluate its performance using JISK-
Evaluation was made according to 5400. The results are shown in Table-1. Compounding treatment cyclobentadiene resin 0-60 (parts) High styrene resin (Goodyear Mori's Priorite S-
Spots) 100-40 Titanium oxide (Ishihara Sangyo Co., Ltd. Tybek R-630> 100 Xylene 200
Table 1 I From the results, the composition of the present invention was improved in terms of adhesion, drawing test, alkali resistance, acid resistance, etc., compared to the composition without cyclobentadiene resin (Experiment No. 1). I can see that it is being done.

However, if the amount of cyclobentadiene resin is greater than the amount of hystyrene resin (Experiment No. 5), it is not preferable because hardness, Erichsen test, bending resistance, DuPont impact strength, etc. are decreased. Example 2 A cyclobentadiene-based resin having a softening point of 12,000 obtained by thermally polymerizing a mixture of 7-part dicyclobentadiene and 3-part isoprene at 26,000 in the presence of a xylene solvent for 3 hours was used in Example 1. When the compound was mixed in exactly the same manner as in Experiment No. 3 except that it was used in place of the cyclobentadiene resin, and its performance was evaluated, the adhesion of the coating was 100/100.
, No change was observed in alkali resistance for 10 days.

Comparative Example The same method as in Experiment No. 3 was used except that a commercially available petroleum resin (Neopolymer-120, softening point 120, manufactured by Nippon Petrochemicals) was used instead of the cyclobentadiene resin, and its performance was evaluated. It takes 6 hours to dry the
A result of 10 skin or less was obtained in the DuPont impact test.

Claims (1)

[Scope of Claims] 1. In a room temperature drying paint containing a styrene copolymer resin as a component in the binder, i. per 100 parts by weight of the styrene copolymer resin, ii. Pentadiene resin 5-100
An improved styrene copolymer resin coating composition characterized in that it contains parts by weight of styrene copolymer resin. 2. The composition according to claim 1, wherein the styrene copolymer resin has a glass transition temperature of 20°C or higher. 3. The composition according to claim 2, wherein the styrene copolymer resin is a styrene-butadiene copolymer. 4. The composition according to claim 1, wherein the styrene copolymer resin content in the binder is 30% by weight or more. 5 The cyclopentadiene resin is obtained by thermally polymerizing a monomer component consisting of 50 to 100% by weight of a cyclopentadiene monomer and 50 to 0% by weight of a comonomer copolymerizable therewith. The composition according to claim 1, which is a composition according to claim 1. 6. The composition according to claim 5, wherein the cyclopentadiene monomer is cyclopentadiene, alkylcyclopentadiene, or a dimer, trimer, or codimer thereof. 7. The composition according to claim 5, wherein the copolymer is a diolefinic monomer, a monoolefinic monomer, or a polar vinyl monomer.