JPS647082B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel vinyl polymer emulsion with excellent coating performance. As is well known, water-based paints are attracting attention as one of the anti-pollution and resource-saving paints, and among them, synthetic resin emulsions are widely used as resins for water-based paints. However, for example, vinyl acetate-based or acrylic-based emulsions, which are typical synthetic resin emulsions, have excellent drying properties, but because they use emulsifiers and protective colloids during polymerization, they suffer from decreased water resistance. It has its drawbacks. Furthermore, due to the film forming mechanism, the film tends to be porous, and its corrosion resistance is at a low level. From this point of view, research has been conducted on polymer emulsifiers or reactive polymer emulsifiers that can replace water-soluble or hydrophilic low-molecular-weight emulsifiers, which are a major factor in the deterioration of performance such as water resistance. For example, vinyl emulsion using a neutralized aqueous solution of maleated oil or maleated alkyd resin as an emulsifier (US Pat. No. 2,941,968), emulsion using a neutralized aqueous solution of maleated polybutadiene as an emulsifier (Japanese Patent Publication No. 49-43381), etc. is publicly known. However, when a vinyl monomer is emulsion polymerized in the presence of a neutralized aqueous solution of maleated oil or maleated alkyd resin, the polymerization is inhibited and it is difficult to increase the molecular weight. It has the disadvantage that sufficient coating film performance cannot be obtained. In addition, in the latter method, when a maleated product of 1,4-polybutadiene is used, graft polymerization with the vinyl monomer hardly occurs during emulsion polymerization, resulting in poor emulsion stability and poor coating film quality. It has the disadvantage of poor physical properties such as water resistance and corrosion resistance. 1,2-
When maleated polybutadiene is used as an emulsifier, it has a large crosslinking property and gels inside the particles to form macromolecules, which has the disadvantage of poor coating workability when used as a paint. On the other hand, the present inventors have already found that within the monomer unit,
An adduct of maleic acid (anhydride) and an amorphous dicyclopentadiene ring-opening polymer (DCPD polymer), which has a unique structure containing both chain and cyclic carbon-carbon unsaturated double bonds (maleated DCPD) We proposed water-soluble or water-dispersible film-forming substances obtained by neutralizing these polymers. Focusing on the fact that this new adduct has unique properties and chemical structure as a coating film-forming substance, we conducted various studies and found that
We have arrived at the present invention. Compared to the existing technology, the vinyl polymer emulsion of the present invention has a much faster coating film drying time, and surprisingly, the coating can be almost completely cured in a short time at low temperatures without the addition of a metal dryer. The goal is to demonstrate performance close to that of membranes. This is because the maleated DCPD polymer used in the present invention has a strongly hydrophilic oxycarbonyl group partially bonded to a strongly hydrophobic resin skeleton, and the glass transition temperature of this resin skeleton is high. This seems to be caused by. In addition, if a metal dryer is used in the present invention,
By oxidatively curing the unsaturated groups in the resin skeleton, it exhibits even more perfect coating performance. others,
The vinyl polymer emulsion according to the present invention has a fine average particle diameter and is excellent in storage stability and pigment dispersibility. It has also been found that the cured coating film obtained is highly glossy and highly transparent, and is also significantly superior in water resistance. The present invention uses a neutralized aqueous solution of an adduct of a substantially amorphous dicyclopentadiene ring-opened polymer represented by the chemical structural formula below and maleic acid (anhydride) as an emulsifier. This invention relates to a vinyl polymer emulsion obtained by emulsion polymerization of polymers. The number average molecular weight of the maleated DCPD resin used in the present invention is preferably 500 to 50,000, and preferably 1,000 to 50,000.
~10000 is more preferred. The DCPD polymer used in the present invention can be any amorphous DCPD ring-opening polymer shown in formula (1) above, regardless of the manufacturing method. For example, JP-A-53-
92000, and the method disclosed in Japanese Patent Application Laid-open No. 53-111399. The maleation reaction can be carried out by a conventional method.
For example, it is sufficient to add maleic acid or maleic anhydride, a solvent, and additives as necessary, and heat the mixture to 150 to 250°C while stirring and thoroughly purging with nitrogen.
After that, it is neutralized and water-solubilized. Basic substances for neutralization include ammonia, amines or alkali metal hydroxides,
Examples include oxides, carbonates, and bicarbonates. As the amines, commonly used polyvalent amines such as primary, secondary, or tertiary amines, diamines, triamines, and tetramines can be used. The degree of maleation is such that the acid value of the maleated DCPD polymer is preferably 30 to 500, more preferably
It is desirable to adjust it to 50-300. In addition, a compound having a functional group that reacts with an anhydride group, such as a compound having an amino group, a hydroxyl group, an epoxy group, etc., may be used to partially modify maleation.
DCPD polymers can be used as well. A wide variety of vinyl monomers can be used as the vinyl monomer in the present invention, but it is not preferable to use a large amount of a vinyl monomer that is too hydrophilic, as in the case of general emulsion polymerization. Vinyl monomers include aromatic vinyl compounds, acrylic esters,
Examples include methacrylic acid esters, glycidyl acrylate derivatives, glycidyl methacrylate derivatives, and conjugated diene compounds. Examples of aromatic vinyl compounds include styrene, vinyltoluene, α-methylstyrene, and divinylbenzene. Esters of acrylic acid and methacrylic acid have the general formula CH ₂ =C(R ₁ ).
Acrylic acid esters, methacrylic acid esters, ethylene glycol monoalkyl ether, propylene glycol represented by COOR ₂ (where R ₁ represents hydrogen or a methyl group, and R ₂ represents an alkyl group having 1 to 30 carbon atoms) Esters of monoalkyl ether or diethylene glycol monoalkyl ether (alkyl group has 1 to 8 carbon atoms) and acrylic acid or methacrylic acid, such as allyl acrylate, allyl methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, diethylaminoethyl methacrylate , allyloxyethyl acrylate, allyloxyethyl methacrylate, and the like. Other glycidyl acrylate, glycidyl methacrylate and their derivatives (1 to 30 carbon atoms)
adducts with carboxylic acids), butadiene, pentadiene, isoprene as conjugated diene compounds,
Examples include chloroprene. These polymerizable vinyl monomers can be used alone or in combination of two or more. Furthermore, acrylic acid, methacrylic acid, itaconic acid, acrylamide, methacrylamide, N-methylacrylamide, N-methylolated acrylamide, dimethylaminoethyl methacrylate, N-methylolated methacrylamide, hydroxyethyl other than the vinyl monomers mentioned above. A small amount of water-soluble or hydrophilic vinyl monomers such as acrylate, vinylpyridine, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, and vinylpyrrolidone can also be used in combination. In the present invention, in order to carry out emulsion polymerization of a polymerizable vinyl monomer, a neutralized aqueous solution of a maleated DCPD polymer, a vinyl monomer, a radical initiator, and, if necessary, a water-soluble or It is carried out at a temperature between 0 and 100°C in the presence of a hydrophilic organic solvent. As the radical polymerization initiator, either water-soluble or oil-soluble can be used effectively, such as inorganic initiators such as ammonium persulfate, potassium persulfate, water peroxide, etc., benzoyl peroxide, azobisisobutyronitrile, cumene hydro Examples include organic initiators such as peroxides.
In addition, water-soluble and oil-soluble redox initiators, actinic rays, photosensitizers and actinic rays, ionizing radiation, ultrasonic waves, and the like are also effectively used. Examples of water-soluble or hydrophilic organic solvents include alcohol solvents, ether solvents, ester solvents, amide solvents, and ketone solvents. The ratio of the maleated DCPD polymer and these vinyl monomers used in the present invention can be any ratio as long as a stable emulsion is produced, but in general The acid value in the previous total solid content is about 3~
It is preferable to carry out the test so that the total number becomes 150. The aqueous emulsion synthesized by the method of the present invention contains pigments such as drying agents such as cobalt naphthenate and manganese naphthenate, titanium white, calcium carbonate, silicic anhydride, wetting agents, and plasticizers as a paint vehicle. By adding a thickener, water, etc., an emulsion paint with excellent coating film performance such as drying properties and water resistance can be made as described above. In addition, it can be widely applied to adhesives and other uses by taking advantage of its strong adhesion. Hereinafter, the present invention will be specifically explained using typical examples, but without being limited thereto,
Various modifications and improvements are possible within the scope of the invention. Manufacture of maleated DCPD polymer: Reference Examples 1 to 3 The amorphous dicyclopentadiene ring-opening polymers used as raw material resins were all disclosed in Japanese Patent Application Laid-open No. 53-92000.
Manufactured by the method disclosed in . After dissolving the raw material DCPD resin in tetralin, predetermined amounts of maleic anhydride, BHT, and antigelation agent were added, and the mixture was heated to 190°C to carry out an addition reaction of maleic anhydride with stirring. After diluting the reaction solution with xylene, it was poured into a large amount of methanol to precipitate the polymer, and the resulting polymer was vacuum-dried at 60°C. Next, the obtained resin was dispersed in ion-exchanged water, butyl cellosolve and triethylamine were added, and the mixture was heated and stirred at 80 to 90°C to obtain a uniform and transparent neutralized aqueous solution. The results are summarized in Table-1.

[Table] Example 1 65.1 g of the aqueous solution obtained in Reference Example 1 (maleated DCPD polymer 10
g, 48 g of water, 5.3 g of butyl cellosolve, 1.8 g of triethylamine), and 25.8 g of butyl methacrylate were added, and nitrogen gas purging was performed several times. Next, the temperature was raised to 50 to 60°C with strong stirring to thoroughly emulsify it, and then 0.0625 g of ammonium persulfate was added in two portions, and after the temperature was raised to 80°C, polymerization was carried out for 6 hours. The obtained emulsion was a slightly transparent emulsion and a homogeneous solution. The solid content of the generated emulsion was 40.1%, and the polymerization conversion rate of butyl methacrylate calculated from the solid content was 103
%, indicating that butyl methacrylate was completely polymerized. Next, when the particle size of the emulsion was measured using an electron microscope, it was found to be 0.04μ, which was found to be a very fine particle size. The coating film obtained by applying this emulsion to a glass plate and drying it was a transparent, hard, and high-gloss coating film. Examples 2 to 5 Emulsions were produced using the same equipment and method as in Example 1. Its manufacturing conditions and properties are shown in Table 2. The coating films obtained by applying the emulsions of Examples 2 to 5 on glass plates and drying them were transparent and had high gloss. Examples 6 to 8 The emulsions of Examples 2, 4, and 5 and each emulsion were mixed with titanium white at 20% of the resin content and dispersed and applied to a glass plate, and the changes in hardness and water resistance over time were measured. did. The results are shown in Table 3 together with the results for commercially available acrylic emulsions for comparison. For titanium white, a commercially available dispersed pigment (trade name: Aquafain Color E, manufactured by Dainichiseika Kaisha, Ltd.) dispersed in a small amount of water-soluble acrylic was used.

【table】

[Table] Time taken until blisters appear after soaking.

Claims (1)

[Scope of Claims] 1. A neutralized aqueous solution of an adduct of a substantially amorphous ring-opened dicyclopentadiene polymer represented by the chemical structural formula below and maleic acid (anhydride) is used as an emulsifier to produce vinyl. A vinyl polymer emulsion obtained by emulsion polymerization of monomers. 2. The vinyl polymer emulsion according to claim 1, wherein the adduct has a number average molecular weight of 500 to 50,000 and an acid value of 30 to 500. 3. The vinyl system according to claim 1 or 2, wherein the adduct is an adduct in which an anhydride group is partially modified with a compound having a functional group such as an amino group, a hydroxyl group, or an epoxy group. Polymer emulsion. 4 The vinyl monomer is an aromatic vinyl monomer,
Claim 1, which is acrylic esters, methacrylic esters, glycidyl acrylate derivatives, glycidyl methacrylate derivatives, butadiene, isoprene, and chloroprene;
The vinyl polymer emulsion according to item 2 or 3.