JPS60228573A - Coating compositon - Google Patents

Abstract

PURPOSE:To provide a coating compsn. which gives a coating film having excellent dryness and resistance to weather, water and corrosion, etc., containing a film-forming natural oil and a graft polymer obtd. by grafting a vinyl monomer onto a cyclopentadiene polymer. CONSTITUTION:A cyclopentadiene monomer alone or a mixture thereof with a copolymerizable monomer such as methyl acrylate or styrene is polymerized to prepare a cyclopentadiene polymer. A vinyl monomer such as methyl methacrylate or 1,3-butadiene is grafted onto the cyclopentadiene polymer in the presence of a radical polymn. initiator. The resulting graft polymer and a film-forming natural oil such as linseed oil or safflower oil are used as vehicle component to prepare the desired coating compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating composition with improved film properties, and more specifically, a coating composition containing a natural oil-based film-forming agent and a vinyl monomer grafted product of a cyclopentadiene-based polymer as a vehicle component. The present invention relates to a coating composition having excellent drying properties, weather resistance, water resistance, etc.

Oil-based phenols containing natural drying oils or their processed oils as film-forming components have been widely used.

In this case, the disadvantage is that it has poor drying properties and weather resistance.
As an improvement method, a method of modifying with a cyclopentadiene polymer (JP-A No. 55-13717, No. 56-8)
2851, etc.), a method of further modifying a natural oil-based film-forming component modified with a cyclopentadiene polymer with a phenol resin (JP-A-56-84755, JP-A No. 56-10)
No. 0867), etc. have been developed.

However, even with the oil-based phenos obtained by these methods, drying properties at low temperatures and room temperatures are still not sufficient, and water resistance and weather resistance are also somewhat difficult.

The inventors of the present invention have carried out intensive studies to improve these drawbacks of the conventional technology, and as a result, they have solved these drawbacks by mixing a natural oil-based film-forming agent with a vinyl monomer grafted product of cyclopentadiene polymer. They have found a way to overcome this problem and have completed the present invention.

The main object of the present invention is to provide a coating composition with excellent drying properties, and another object is to provide a coating composition with excellent film performance such as weather resistance and water resistance.

These objects of the present invention are to combine (A) a natural oil film-forming agent and (B) a grafted product obtained by graft polymerizing a vinyl monomer onto a cyclopentadiene polymer as a vehicle for a coating composition. This is achieved by making it an ingredient.

The component (B) used in the present invention is obtained by graft polymerizing a vinyl monomer to a cyclopentadiene polymer, and usually has a weight average molecular weight of 3,000 or more, preferably 000 to 5QOOO. It is.

The cyclopentadiene polymer used may be either oily or resinous, and in the case of the former, it usually has a viscosity of 100 centipoise or more at 25°C, preferably 200 centipoise or more.
It is more than centipoise.

In the latter case, the softening point is usually 160°C or lower, preferably 1
The temperature is 50°C or less. At this time, if the viscosity of the polymer is too low, the effect of improving the drying properties of the grafted product will tend to decrease, while if the softening point is too high, gels will tend to form during the grafting reaction.

Although the composition of such a polymer is appropriately selected, it is usually a homopolymer or copolymer having a cyclopentadiene monomer content of 30% by weight or more, preferably 40% by weight or more. The higher the content of the cyclopentadiene monomer, the better the graft polymerization properties, but if the content is too high, it is difficult to obtain an oily product or a resin with a low softening point. Copolymers with a content of 40 to 90% by weight are used.

The cyclopentadiene monomer used in polymerization includes cyclopentadiene, lower alkyl-substituted cyclopentadiene such as methyl-substituted and ethyl-substituted cyclopentadiene, and dimers thereof;
Low Diels-Alder adducts such as dimers and codimers, and mixtures thereof; comonomers include monoolefins such as ethylene, propylene, butene, pentene, styrene, and α-methylstyrene. , 1.3-
Examples include conjugated dienes such as butadiene, inogren, and 1,3-pentagenato, vinyl monomers with polar groups such as vinyl acetate, vinyl propionate, acrylic esters, methacrylic esters, acrylonitrile, acrolein, and allyl alcohol. Ru.

Such cyclopentadiene polymers include Beyze/,
A method of thermally polymerizing a cyclopentadiene monomer or a mixture of the monomer and a comonomer in the presence or absence of an inert solvent such as toluene, xylene, etc. (e.g., JP-A-53-98383) ), cationic polymerization, and other known methods.

On the other hand, any vinyl monomer may be used as long as it has radical polymerization activity.

Specific examples include unsaturated monocarboxylic acid esters such as methyl acrylate, methyl methacrylate, methyl crotonate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; vinyl acetate;
Vinyl propionate, acrylonitrile, styrene, α
Examples include -methylstyrene, vinyltoluene, L3-butadiene, isoprene, L3-pentadiene, butene, and pentene, among which unsaturated monocarboxylic acid esters are preferred in terms of weather resistance and drying properties.

The ratio of the cyclopentadiene polymer to the vinyl monomer is appropriately selected depending on the performance of the desired grafted product, but usually 80 to 20% of the cyclopentadiene polymer is used.
% by weight, preferably 65-35% by weight and 20-80% by weight of vinyl monomer.

Preferably the proportion is 35 to 65% by weight.

Further, the radical initiator is not particularly limited as long as it is commonly used, and specific examples include diacyl peroxide such as benzoyl peroxide; cumene hydroperoxide, t-butyl hydroperoxide. Hydroperoxides such as di-t
-Butyl bar peroxide; Examples include azo compounds such as azobisisobutyronitrile oxide and dialkylated compounds such as dicumyl peroxide.

These radical initiators are appropriately selected and used depending on polymerization conditions such as polymerization temperature and polymerization time.

The amount of the radical initiator used is appropriately selected depending on the desired performance of the polymer, but is usually in the range of 0.1 to 10% by weight based on the total polymerizable components, particularly 0.1 to 10% by weight based on the total polymerizable components.
A graft polymer having excellent performance can be efficiently obtained in the range of 3 to 5% by weight.

Polymerization reactions using radical initiators include toluene, xylene,
This is carried out at 60-260° C. for 0.5-20 hours in the presence or absence of a known inert solvent such as mineral spirits. Polymerization using a radical initiator may be carried out either batchwise or continuously.

After the radical polymerization is completed, the desired graft polymer can be obtained by removing unreacted monomers and by-produced low-volatility fractions according to a conventional method. Such graft polymers may be liquid, semi-solid, or
There are many types such as solids, but in the case of liquids, it is usually 25℃
The viscosity is IQOOO centiboise or more, and in the case of a solid, the softening point is 170° C. or less.

Component (A) used in the present invention is a film-forming agent based on natural oil, and may be any one conventionally known as a vehicle component for oil-based phenols or oil-based paints. The content of the natural oil component in the film forming agent is usually 20% by weight or more, preferably 40% by weight or more. Specific examples of such film-forming agents include linseed oil,
Tung oil, safflower oil, dehydrated castor oil, soybean oil, nino oil,
Natural oils with an iodine value of 100 or more such as fish oil, stand oils and homolyzed oils made from these natural oils, and denaturation of these natural oils or their processed oils with dicyclopentadiene or cyclopentadiene polymers. Examples thereof include modified products, alkyd resins containing natural oil components, and the like. Among these, a heated reaction product of an oily or resinous cyclopentadiene polymer and a natural oil is particularly preferred in terms of weather resistance, corrosion resistance, and the like.

These film-forming agents may contain modifiers such as phenolic resins, or may be given an acid value by an appropriate method such as addition of maleic anhydride.

The ratio of component (4) and component (B) used in the present invention is appropriately selected depending on the purpose of use, but usually, component (A) 1
5-85% by weight, preferably 20-75% by weight and (B)
The proportion of the components is from 85 to 15% by weight, preferably from 80 to 25% by weight. As the amount of component (A) increases, the performance of the film, such as dryness, weather resistance, water resistance, and corrosion resistance, tends to decrease, and as the amount of component (A) decreases, the weather resistance,
Water resistance, corrosion resistance, etc. decrease.

These two components can be mixed as necessary and then diluted with a diluting solvent to form an oily phenol. In particular, when an oily grafted product is used as component (B), the viscosity of the system is lowered, so that a solvent-free or high-solid oily phenol can be obtained.

Further, if desired, various enamels can be prepared by adding pigments such as titanium white, zinc white, and aluminum powder, and paint compounding agents such as fillers, pigment dispersants, and drying agents. Furthermore, it is also possible to blend such oil-based pheno with a substance that is normally used as a vehicle component for oil-based paints, such as an alkyd resin.

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 separable flask was charged with cyclopentadiene polymer in the proportions shown in Table 1, and various vinyl monomers and 3 parts of tertiary-butyl peroxide were added.
A grafted product of cyclopentadiene polymer was obtained by graft polymerization at 0° C. for 3 hours. The results are shown in Table 1.

Example 1 30 parts of the grafted product obtained in Reference Example 1 and 70 parts of homolized linseed oil were diluted with 17 parts of mineral turpentine, and further, as a dryer 7, 1.0 part of cobalt naphthenate (5 Ti) and lead naphthenate ( An oil-based face was prepared by adding 3.4 parts of 15g), and this face was applied to an untreated cold-rolled steel plate to a dry film thickness of 15μ, and after drying for 7 days, a clear coating film was evaluated. The results are shown in Table 2.

*2 According to JISK-5400.

* Severity of blistering after 200 hours of soaking in hot water at 340°C: No change ◎, Slight blistering (occurred after 90 hours) ○, Blistering (i.

*Severity of blistering after 100 hours at 450°C and 100% temperature: No change ◎, Slight blistering (5
(occurred in 0 hours) ○, blistering (occurred in 15 hours) × *55% NaCl 1 smooth spray, extent of surface rust area after 200 hours: Rust area 0 to 5 ◎.

5 to 15 ○, 15% or more × *6 Weather Ometer After 200 hours, the degree of discoloration, shrinkage, and cracks on the paint film: No change ◎, slight discoloration ○, shrinkage, cracks × (same below) ) From these results, it was found that by incorporating a grafted product of cyclopentadiene polymer, drying properties and weather resistance were improved.
It can be seen that it has excellent water resistance and corrosion resistance.

Example 2 The grafted product (C) obtained in Reference Example 1 and homolated linseed oil were mixed in the proportions shown in Table 3, and the coating film was evaluated according to Example 1. The results are shown in Table 3.

This result shows that even if the proportion of the grafted product used is changed, a coating film with excellent physical properties such as drying properties, weather resistance, and water resistance can be obtained.

Example 3 50 parts of the cyclopentadiene polymer used in Reference Example 1 was charged into a separable flask, and 30 parts of butyl acrylate was added.
20 parts of ethyl acrylate and 3 parts of ditertiary-butyl peroxide were added, and graft polymerization was carried out at 150°C for 3 hours to obtain a transparent oily cyclopentadiene polymer having a viscosity of 8 QOOOO centipoise and a hue (Gardner color number) of 2 at 25°C. A combined acrylic grafted product was obtained. Next, coating film evaluation was performed according to Example 1. The results are shown in Table 4.

Table 4 Example 4 50 parts of the grafted product (D) obtained in Reference Example 1 and 50 parts of various natural oil-based film forming agents were mixed, and the coating film was evaluated in accordance with Example 1. The results are shown in Table 5.

Table 5 *1 Oxidation 30 parts of acid-modified cyclopentadiene polymer with a viscosity of 6000 centipoise at 20.25°C and 70 parts of linseed oil were reacted by heating at 280°C for 5 hours.Oil with a viscosity of 3000 centipoise at 25°C Material *2 Semi-solid material with a softening point of 60°C obtained by heating and reacting 60 parts of linseed oil, 30 parts of cyclopentadiene polymer, and 10 parts of phenolic resin at 280°C for 2 hours *3 Oxidation 15, with a softening point of 135°C QN 2325 (
Nippon Zeon Co., Ltd.) 20 parts and 80 parts of linseed oil were reacted by heating at 280°C for 2 hours.
500 centimeter void oil*4 long oil type soybean oil modified alkyd resin (Beccosol P
-470. (manufactured by Dainippon Ink & Chemicals) From this result,
It can be seen that even if the type of natural oil-based film forming agent is changed, a coating film with excellent physical properties such as weather resistance, water resistance, and corrosion resistance can be obtained.

Patent applicant: Zeon Corporation

Claims (1)

[Claims] 1. A coating composition comprising (A) a natural oil film forming agent and (B) a grafted product obtained by graft polymerizing a vinyl monomer onto a cyclopentadiene polymer as vehicle components.