JPS59155413A - Resin dispersion and its production - Google Patents

Abstract

PURPOSE:An aqueous dispersion useful for paining, impregnation and bonding, prepared by dispersing in water a cationic or amphoteric copolymer free of an emulsifier and protective colloid, obtained by using a specified alpha,beta-ethylenically unsaturated monomer; and a method for producing the dispersion. CONSTITUTION:2-35pts.wt. tert. amino group-containing alpha,beta-ethylenically unsaturated monomer (e.g., dimethylaminoethyl acrylate) is polymerized with 98-65pts.wt. another alpha,beta-ethylenically unsaturated monomer copolymerizable therewith (e.g., vinyl acetate) in a solution of polyalkylene glycol, MW of 600- 20,000, in a water-soluble solvent. The obtained copolymer is dispersed in water to obtain the desired aqueous resin dispersion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel and useful resin dispersion and a method for producing the dispersion. This invention relates to an aqueous dispersion of a cationic or amphoteric copolymer (hereinafter abbreviated as vinyl copolymer) that does not contain so-called emulsifiers and protective colloids (hereinafter abbreviated as vinyl copolymer), which is obtained using a so-called emulsifier and protective colloid, and a method for producing the same.

Water-based paints have attracted particular attention in recent years because they are low-pollution and resource-saving, and there are base resin types, water-soluble and water-dispersible types, each with their own characteristics. However, the drying properties, water resistance, gloss, and adhesion of coating films to substrates remain issues that need to be solved.

Among these, water-soluble type resins are so-called anionic resins, in which the carboxyl groups present in the resin are neutralized and dissolved with alkali such as ammonia or amines.
A so-called cation type resin, in which the tertiary amine 7 groups present in the resin are neutralized and dissolved with acid, is already commercially available, and both types of resin have excellent gloss and adhesive properties. Although it is good, since the amount of organic solvent is usually 30 to 50% by weight,
There are also problems in terms of anti-pollution measures, and there are disadvantages in that the drying properties and water resistance of the coating film are poor.

On the other hand, dispersions obtained by emulsion polymerization in the presence of emulsifiers and protective colloids or dispersions obtained by mechanical dispersion can contain high molecular weight polymer molecules regardless of the viscosity of these dispersions. However, it can be made to have a low viscosity even if it has a high solid content concentration, and it has excellent drying properties because it does not use organic solvents or amines that affect safety and odor. However, it has drawbacks such as poor coating gloss and workability, and poor coating film water resistance and poor adhesion to substrates due to the effects of the emulsifiers and protective colloids used.

Therefore, colloidal dispersion resins that take advantage of the advantages of both water-soluble resins and water-dispersible resins are currently being studied.

Against this background, the present inventors conducted intensive studies to solve the various pending problems, and as a result, introduced a polymerizable vinyl monomer having a tertiary amino group as an essential monomer to the polymerization reaction system. Furthermore, an aqueous resin dispersion obtained by adding water to a vinyl copolymer solution obtained by using a water-soluble solvent solution containing a specific amount of polyalkylene glycol as a medium is made of an emulsifier and a protective colloid. The present invention was completed based on the discovery that it is stable in itself without being used, and that it provides a coating film with high adhesion and excellent water resistance.

That is, in the present invention, a monomer mixture consisting of 2 to 35 parts by weight of a polymerizable vinyl monomer having a tertiary amino group and 98 to 65 parts by weight of a polymerizable vinyl monomer that can be copolymerized with the monomer mixture, The present invention provides an aqueous dispersion of a vinyl copolymer obtained by polymerizing a polyalkylene glycol having a molecular weight of 20,000 in a solution of a water-soluble solvent; There is also provided a process for producing an aqueous resin dispersion comprising polymerizing the monomer mixture described above in a solvent solution and then dispersing the resulting vinyl copolymer in water.

Here, in the present invention, the above-mentioned tertiary amino group-containing polymerizable vinyl monomer is used as an essential component compound because the copolymer obtained using the above-mentioned polymer is water-resistant when acid-neutralized. This is aimed at the R effect of imparting dispersibility and exhibiting excellent adhesion to various substrates, and on the other hand, it is polymerized in a system containing the polyalkylene glycol. In this case, chemical bonding (grafting, etc.) and physical fusion between the vinyl copolymer and the polyalkylene glycol proceed simultaneously, and the vinyl copolymer becomes a polymer with self-dispersing ability, which promotes the dispersion effect. The aim is to

Typical examples of the tertiary amino group-containing polymerizable monomer used in the present invention include dialkylaminoalkyl (meth)acrylates such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate. , vinylpyridine,
These include vinylpyridines such as 2-methyl-5-vinyl and lysine; dialkylaminoalkyl vinyl ethers such as dimethylaminoethyl vinyl ether; and alkylamino group-containing (meth)acrylamides such as dimethylaminoethyl (meth)acrylamide. may be used alone or in combination of two or more.

Typical examples of other polymerizable vinyl monomers that can be copolymerized with these tertiary amino group-containing polymerizable vinyl monomers include vinyl esters such as vinyl acetate, vinyl propionate, and persatic acid; ) Alkyl esters of (meth)acrylic acid such as methyl acrylate, ethyl (meth)acrylate, butyl (meth)acrylate; aromatic vinyl compounds such as styrene and vinyltoluene; α-olefins such as ethylene; butadiene Dienes such as; vinyl halides such as vinyl chloride and vinylidene chloride; vinyl ethers such as methyl vinyl ether; dialkyl esters of unsaturated dibasic acids such as dialkyl maleate, dialkyl fumarate, dialkyl itaconate, etc. There is,
These may be used alone or in combination of two or more.

Furthermore, as necessary, unsaturated acids such as α, β-unsaturated ethylenically carboxylic acids, vinyl sulfonic acid, styrene sulfonic acid, or salts thereof; (meth)acrylamide or N-methylolated products thereof or the methylolated products; Alkoxylated products: α, β-ethylenically unsaturated monomers containing hydroxyl groups such as β-hydroxyethyl methacrylate; α, β-containing glycidyl groups such as glycidyl (meth)acrylate and allyl glycidyl ether
-Ethylenically unsaturated monomers can also be used in small amounts, and those copolymerized with special tsuric acid monomers form amphoteric aqueous dispersions, which exhibit distinctive performance.

In the composition of the vinyl copolymer, the above-mentioned tertiary amino group-containing 11-polymerized vinyl monomer is set at 2 to 35 parts by weight because if it is less than 2 parts by weight, the water dispersibility will be insufficient. Moreover, since the cationic property decreases, properties such as adhesion cannot be fully exhibited, and conversely, when the amount exceeds 35 parts by weight, the hydrophilicity increases and the water resistance decreases. It is limited because it is difficult to obtain the desired dispersion due to its high water solubility. More preferably 5 parts in 100 parts by weight of total vinyl monomers
It is preferable to set it within the range of 15 parts by weight.

On the other hand, the amount of the polyalkylene glycol used in combination is determined based on the balance between the dispersibility imparting effect of the vinyl copolymer and the desired performance such as water resistance of the coating film, as well as the desired degree of neutralization of the resin dispersion. However, if the amount of the polyalkylene glycol used is 10 parts by weight or more based on 0 parts by weight of the total polymerizable vinyl monomer, vinyl copolymerization can be achieved without neutralization. It has the advantage that aqueous dispersion of the coalescence is possible.

However, even if the amount used exceeds 20 parts by weight, the grafting efficiency will hardly be improved, and moreover, the water resistance will deteriorate. On the other hand, if the amount used is less than 1 part by weight, it becomes difficult to obtain a dispersing effect.

Regarding the molecular weight of the polyalkylene gellicol, if it is less than 600, it will have poor hydrophilicity and no dispersion effect can be expected, whereas if it has a molecular weight exceeding 20,000, it will not be possible to graft with the vinyl copolymer. Fusion with the copolymer is also difficult to occur, and the dispersion effect is not improved.

Typical examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, and block copolymers of these polyethylene glycols and polypropylene glycol.
These may be used alone or in combination of two or more.

In order to prepare a resin dispersion by dispersing the vinyl copolymer obtained using the various raw materials listed above in water, there are two methods: a method of dispersing using only water, and a method of dispersing using water and acids. However, it is preferable to use the former method when preparing an amphoteric dispersion, and the latter method when preparing a cationic dispersion.

Typical acids used to neutralize the resin dispersion include organic acids such as formic acid and acetic acid, and inorganic acids such as hydrochloric acid. Select a material that has the ability to dissolve the vinyl copolymer, does not cause problems such as wrinkles or sag when it is made into a paint, and has excellent drying properties and is suitable for application. Desirably, water-soluble ones such as alcohols, cellosolves, calpitols, and derivatives thereof are applicable, and any known and commonly used ones can be used as they are.

The amount of the water-soluble solvent to be used is preferably in the range of 20 to 100 parts by weight based on 100 parts by weight of the resin solid content of the resin dispersion. If it is less than 20 parts by weight, the viscosity of the solution will increase during the reaction, which will hinder the progress of the polymerization reaction.
On the other hand, if it exceeds 100 parts by weight, the viscosity of the resin dispersion increases and the dispersion stability decreases, which goes against the purpose of resource conservation.

More preferably, it should be designed to be kept at 30% by weight or less in the final resin dispersion.

Further, the amount of the solvent can be further reduced by adding water or the like to the vinyl copolymer solution for dispersion and then distilling a low boiling point water-soluble solvent under reduced pressure.

The above-mentioned polymerization reaction may be carried out according to a conventional solution polymerization reaction method, and is not particularly complicated.

Next, the vinyl copolymer resin solution can be dispersed in water by adding the resin solution into water and dispersing it, or conversely by injecting water into the resin solution and dispersing it. It is desirable that the

On the other hand, the acids used to neutralize the aqueous resin dispersion can be mixed either on the side where they are added or injected, or conversely on the side where they are added or injected. In order to obtain a stable dispersion, a method is adopted in which a fixed amount of acids is first mixed into a resin solution, and then water is added and injected into the neutralized resin solution to disperse it. is desirable.

The thus obtained dispersion of the present invention can be used as it is as a coating agent, but if necessary, pigments, plasticizers or other solvents may be added to the dispersion of the present invention, or other miscible substances may be added to the dispersion of the present invention. It can also be used as a blend with water-based resins.

The resin dispersion of the present invention can be obtained as a cationic or amphoteric type, but the cationic type has excellent adhesion to the anionic component in the substrate to be coated, and moreover, it can be used in combination systems. In other words, for example, it has good adhesion to the anionic group in the binder component contained in the undercoat and topcoat paint, or the anionic filler or pigment in other additive components, so it is suitable as a finishing agent. It also has the advantage of improved adhesion.

On the other hand, amphoteric types can also be used in a wide pl+ range, and there is very little or no selectivity of substrates with respect to such adhesion.

Furthermore, the dispersion of the present invention can be directly kneaded with pigments, and has the advantage of having almost no problems with dispersion stability or foaming, unlike emulsion polymers using emulsifiers.

The dispersion of the present invention or the coating composition obtained from the dispersion can be applied by dipping, brushing, spraying, roll coating, etc., and can be applied to wood, paper, fibers, etc. It can be applied to surfaces such as plastics, ceramics, leather, inorganic cement base materials, iron, and non-ferrous metals.

Further, the use of the dispersion liquid of the present invention is not limited to painting, but can be used for a wide variety of purposes such as impregnation and adhesion.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples, where all parts and percentages are based on weight unless otherwise specified.

Example 1 In a 2J2 flask equipped with a stirrer, temperature needle, reflux condenser, addition funnel and inert gas inlet, 300 parts of butyl cellosolve and [polyethylene glycol #600] were added.
0J (Polyethylene glycol manufactured by Daiichi Kogyo Seiyaku ■)
120℃ while blowing in nitrogen gas.
The temperature rose to .

Separately, 455 parts of methyl methacrylate, 210 parts of n-butyl acrylate, and 35 parts of dimethylaminoethyl acrylate were weighed and mixed in advance, and on the other hand, 14 parts of t-butyl hydroperoxide was weighed in advance and the mixture was added from a separate drip port. Dropwise polymerization was carried out in a dropwise manner, taking 3 hours for each drop, and the polymerization was further maintained at the same temperature for 2 hours to complete the polymerization.

After cooling to 5.80°C, a solution of 6 parts of 88% formic acid dissolved in 870 parts of water was added dropwise over 2 hours to ensure dispersion, and then the temperature was lowered to 25°C.

The target resin dispersion thus obtained has a nonvolatile content (N
V) is 40%, the viscosity (Pluck field viscosity at 25°C; hereinafter the same) is 2500 cps, and pl
+ was 5.6.

Example 2 In a flask similar to Example 1, ethylcarpitol 30
0 parts and [polyethylene glycol #6J) OOJ
100 parts of methyl methacrylate, 224 parts of 2-ethylhexyl methacrylate, and 35 parts of dimethylaminoethyl methacrylate were weighed and mixed together, and t-butyl perchlorate was added to the mixture and heated to 100°C in a nitrogen stream. Weighed out 7 parts of oxy-2-ethylhexanoate, injected them from separate dropping ports and allowed them to polymerize dropwise over a period of 3 hours, and then maintained at the same temperature for another 2 hours to polymerize. completed.

Thereafter, the mixture was cooled to 90°C, and 907 parts of water was added dropwise over 2 hours to achieve dispersion, and then the mixture was cooled to 25°C to lower the temperature.

The target resin dispersion obtained here had an NV of 40%, a viscosity of 2500 cps, and a pl+ of 6.1.

150 parts of isopropylene glycol and 150 parts of polyethylene glycol! $4000J (same as above) were charged, and the temperature was raised to 80° C. in a nitrogen stream.

Separately, 266 parts of styrene, 70 parts of methyl methacrylate, 280 parts of 2-ethylhexyl methacrylate and 84 parts of dimethylamino vinyl ether were weighed and mixed in advance,
At the same time, 7 parts of t-butylperoxy-2-ethylhexanoate were weighed out, and these were injected from separate dropping ports to uniformly dropwise polymerize over 3 hours, and then kept at the same temperature for 2 hours. The polymerization was completed by holding the sample.

Then, at the same temperature, 7 parts of 88% formic acid was added to 807
A solution prepared by dissolving a portion of the solution in water was added dropwise over 2 hours to stir the dispersion, and then the temperature was lowered to 25°C.

The resin dispersion obtained here has an NV of 40% and a viscosity of 270.
At 0 cps, the pH was 5.6.

Comparative Example 1 Same as Example 1 except that the same amount of polyethylene glycol #6000J was added and dissolved after the polymerizable vinyl monomer had finished polymerizing, and then dispersed with water. When the above operation was repeated, the viscosity of the system increased significantly and a stable dispersion could not be obtained.

Comparative Example 2 A control sample was prepared in the same manner as in Example 1, except that the same amount of methacrylic acid was used instead of dimethylaminoethyl acrylate, and 876 parts of water was used instead of the formic acid aqueous solution. A resin dispersion was obtained.

This one has an NV of 40%, a viscosity of 310 cps,
The pH was 5.4.

Comparative Example 3 The following raw materials were used by a normal emulsion polymerization method using an emulsifier, with a polymerization temperature of 80°C, a monomer dropping time of 3 hours, and a holding time of 3 hours after completion of the dropping. An emulsion polymer was obtained.

Methyl methacrylate 65 parts n-butyl acrylate 30 methacrylic acid
5〃Sodium dodecylbenzenesulfonate 4〃Ammonium persulfate 0.3〃Water
156.4 total
260.7 The emulsilon obtained here has an NV of 40% and a viscosity of 200
cps, pH was 3.5.

Comparative Example 4 An emulsilone polymer was obtained by the same conventional emulsion polymerization method as in Comparative Example 3, except that the raw materials were changed as follows.

Methyl methacrylate 50 parts n-butyl acrylate 40 methacrylic acid
10 Butyl cellosolve
70 t-butyl peroxybenzoate 1″ triethylamine 12 water
70・total
253〃The emulsion obtained here has an NV of 40%, a viscosity of 20000 cps,
, pl+ was 9.2.

Aqueous resin dispersions obtained in Examples 1 to 3 and Comparative Example 2
A coating material was prepared using the water-based resin obtained in steps 4 to 4 in the manner shown below, and a coating film was formed according to various tests as described below.Then, the various coating films were subjected to performance tests.

Titanium oxide/silica/calcium carbonate-50/40/
10 (weight ratio) PWC = 55% NV = 55% The results of the performance tests are summarized in Table 1, and the judgment criteria for each test are as follows.

〇--------Good △----------Slightly poor X--Poor
It has the advantage that if it is made acidic, the amino groups contained in the resin will be neutralized and act as cations, whereas if it is made alkaline, the carboxyl groups in the resin will be neutralized and act as anions. , this aqueous resin dispersion has a pH of 3~
In the range of 9, the stability of the system is good and an excellent adhesion effect can be exhibited to both the anionic group trA and the cationic substrate.

Incidentally, how the viscosity of this dispersion liquid changes within the above pH range is shown in FIG. 1, which shows the relationship between pH and viscosity.

[Brief explanation of drawings]

Figure 1 shows the relationship between pH and viscosity for the amphoteric type aqueous resin dispersion obtained in Example 2 of the present invention, where the horizontal axis represents pl+ and the vertical axis represents viscosity (cps). )
shall represent. 6 6 γ procedural amendment (voluntary) On March 2, 1980, Kazuo Wakasugi, Commissioner of the Japan Patent Office, 1, Indication of the case, Patent Application No. 29671, filed in 1982, 2, Name of the invention, Resin dispersion and its manufacturing method, 3 , Relationship with the case of the person making the amendment Patent applicant 3-35-58 Sakashita, Itabashi-ku, Tokyo 174 (28
B) Representative of Dainippon Ink & Chemicals Co., Ltd. Shigeru Kuni Nei 4, Agent Address: 6, Dainippon Ink & Chemicals Co., Ltd., 3-7-20 Nihonbashi, Chuo-ku, Tokyo 103, Contents of amendments (11) Between pages 16 and 18, as shown in the attached sheet, Table 1 Note 1) Adhesion: Apply to the substrate with a 6 mil applicator, then apply a two-width cross on the coating after drying for two days. 62) "Water resistance" A coating film was obtained in the same manner as for "adhesion" using a glass sheet as a base material, and then a peel test was performed using cellophane tape and visually evaluated. The coating film was immersed in water, and after 7 days, the adhesion of the immersion coating film and the presence or absence of blisters were checked, and a comprehensive evaluation was made. 3) “Water resistant adhesion” Asphalt/concrete (
A coating film was obtained in the same manner as for "adhesion" using a test panel), and then the coating film was immersed in water for 2 months, and then an adhesion test was conducted for evaluation.

Claims (1)

[Claims] 1. 2 to 35 parts by weight of an α,β-ethylenically unsaturated monomer having a tertiary amino group and other α copolymerizable with this
. 98 to 65 parts by weight of β-ethylenically unsaturated monomer,
An aqueous dispersion of a copolymer obtained by polymerizing a polyalkylene glycol having a molecular weight of 600 to 20,000 in a solution of a water-soluble solvent. In an aqueous solvent solution of polyalkylene glycol having a molecular weight of 2.600 to 20,000, first an α,β-ethylenically unsaturated monomer having a tertiary amino group and other copolymerizable monomers are added. 1. A method for producing an aqueous resin dispersion, which comprises polymerizing α,β-ethylenically unsaturated monomers and then dispersing the obtained copolymer in water.