JPS5941353A - Preparation of hydrosol - Google Patents

Abstract

PURPOSE:To prepare a sol having fine and uniform particle size and storable stably for a long period without using a surface active agent, by adding an alcoholic hydrophilic solvent to a slurry aqueous dispersion obtained by neutralizing a copolymer having an acidic group with an alkali, and stirring the mixture. CONSTITUTION:A copolymer having a weight average molecular weight of 10<4>- 10<6> and composed of 0.1-35wt% of an unsaturated monomer having acidic group (preferably 0.5-20wt% of unsaturated carboxylic acid or 0.2-10wt% of unsaturated sulfonic acid) and 99.9-65wt% of other unsaturated monomer copolymerizable therewith, is mixed with an alkali or an aqueous solution of an alkali to neutralize the whole or a part of the acidic group of said copolymer, and to obtain a slurry aqueous dispersion consisting of said copolymer dispersed in water. 0.1-100pts.wt. of an alcoholic hydrophilic solvent is added to 100pts.wt. of the copolymer, and stirred to disperse said copolymer in water in the form of fine particles having an average particle diameter of 0.01-0.1mum. The solid concentration can be freely controlled over a wide range, and a hydrosol having relatively low viscosity even at a high solid concentration can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to hydro:nol, that is, particles with an average particle diameter of 001 to
0.1/l? The present invention relates to a method for producing an aqueous dispersion in which polymer particles of 100% are stably dispersed in water from a slurry-like aqueous dispersion.

Among aqueous dispersions, in addition to those that can be clearly distinguished as hydrozo/Iz, emulsions, and suspensions depending on the particle size and dispersion state of the dispersoid, there are also those that have a wide particle size distribution and exhibit properties similar to slurry as a whole. . This invention (“from a slurry water dispersion to
This provides a method for obtaining homogenized hydrosil within a small range of 1 to 0.1/(7+1).

Conventionally, as a method for producing a slurry water dispersion, it is known to powder a polymer, add it to water, and then disperse it by stirring at high speed.The slurry water dispersion obtained by this method is There was a problem that the storage stability was poor, and the polymer particles would settle out in a short period of several minutes after slurrying. For this reason, measures are generally taken to improve the stability by adding a surfactant or the like to the aqueous dispersion.

However, the addition of surfactants impairs the water resistance of films formed using aqueous dispersions, causes discoloration, and causes impurity effects, making it difficult to apply slurry-like aqueous dispersions to various applications. can easily cause problems.

Therefore, the inventors discovered that a copolymer having an acid 1 group in the fraction! The above copolymer was compared without using a surfactant by preparing Ij 9 and adding alkali and water to neutralize some or all of the above-mentioned 1-1 biogroups and stirring. We have already proposed a method for obtaining a slurry-like aqueous dispersion that is dispersed in water in a stable state. The slurry-like water dispersion obtained by this proposed method has an excellent feature of greatly improved storage stability compared to that obtained by the conventional method, but it also has poor long-term storage stability. There is still room for improvement. Furthermore, since the slurry-like water dispersion has a large average particle diameter of about 0.1 to several μm and a relatively wide particle size distribution, it has a uniform film-forming ability of 16.

This invention aims to provide a new and useful method for improving the problems of slurry water dispersions obtained by the reverse proposal method, and the gist thereof is to provide unsaturated monomers with acidic groups. A copolymer with a weight average molecular weight of 10 to 106 obtained by copolymerizing 0.1 to 35 weight 96 and 99.9 to 65 weight % of other unsaturated monomers copolymerizable therewith. Add alkalina or alkaline water to 1
- Neutralize some or all gB of the above copolymer, prepare a slurry-like water dispersion in which the -1- above copolymer is dispersed in water, and add an alcohol-based hydrophilic solvent to this water dispersion. ”
- By adding 0.1 to 100 parts by weight to 100 parts by weight of the above copolymer and stirring, the above copolymer can be stabilized in water with an average particle size in the range of 0.01 to 0.1/IrrL. A method for producing hydrosil, which is characterized by obtaining dispersed hydrosil.

The hydrosil obtained by this method has storage stability and uniformity.
It has very good film-forming ability and does not contain any surfactants, so when it is used to form a film, its water resistance may be impaired, or there may be problems caused by surfactants. There will be no discoloration or impurity effects in the pond.

In addition, since the above method is for obtaining hydrosil from a slurry water dispersion, it is very easy to increase the 61u content of hydrosil (+llI).

In this invention, unsaturated l1R4 having a ' radical at 14
Body toko;n, (!: Jii1-ta"'I 1lle
if fli ] In order to market the unsaturated 11tiji body, the bulk jW G method, solution/(E '+1'
Is it possible to employ the known 11 methods of moths such as C agency θ (, milk method, pearl polymerization method, etc.?), especially bulk (11 methods and solution polymerization method using a solvent of 20 + Jj! iI: 96 or less). It is within the "good" range.

This is advantageous because the copolymerization product obtained from these two methods can be used as it is as a raw material for correcting slurry water content.

On the other hand, in polymerization methods such as solution polymerization method, emulsion polymerization method, and pearl polymerization method using large organic solvents (bait for R reaction).
Since the desired medium interferes with the production of a slurry water dispersion, it is necessary to remove it after polymerization. For example, in the solution polymerization method, the organic solvent in the system is removed by distillation or other means to a
Particularly preferably, the copolymer is removed until it is completely removed, and in the emulsion polymerization method, water is removed by solidifying the copolymer at tM by salting out, and in the pearl polymerization method, water is removed by filtering the particulate copolymer. In these water removal steps, the emulsifier used during copolymerization is also removed at the same time.

I used in the present invention: unsaturated monomers having one group;
II12, HumarlIl! Unsaturated carboxylic acids having a carboxyl group as a monomer group, such as 2, styrene sulfonic acid, allyl sulfonic acid, sulfopropyl acrylate, 2-acryloyloxynaphthalene-2-sulfonic acid, 2-methacryloyloxynaphthalene-2- Examples include unsaturated sulfonic acids having a sulfonic group as acidic groups such as sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, and 2-acryloyloxybenzenesulfonic acid, and other unsaturated sulfonic acids having a sulfonic group. One or more of these may be used.

- The amount of the above unsaturated monomer used is 0.1 to 3 in the total monomer.
For example, in the case of an unsaturated carboxylic acid, it is particularly preferably 0.5 to 2 oomq6, and the unsaturated carboxylic acid
RQ r'l'l sulfone awakening place is particularly preferably 0
．． 2~10141m96. When this usage is 0.1 weight iIt 96 less than 1 oka, it is possible to obtain a slurry-like aqueous dispersion. (4: #+' is the child's division νj
It became easier to produce IL sinking year 1, and 35 tons: li, '96
If more 4f is added, the mixture will be water-solubilized without forming a slurry, so the hydrosilation in the next step cannot be carried out satisfactorily in either case.

As copolymerizable unsaturated monomers to be used in combination with the above-mentioned acidic group-containing copolymers, there are various types of ethylenically unsaturated monomers.
'-W'E form, for example, the alkyl group has 1 to 15 carbon atoms
(preferably 3 to 10 acrylic esters and methacrylic esters, vinyl ethers, vinyl esters, acrylonilyl, acrylamide, hydroxyalkyl acrylates, styrene, vinyl chloride,
Ethylene, an ethylenic compound with a functional group such as amino in the molecule! Depending on the intended use, one or two types can be arbitrarily selected and used from the Japanese Uj-i gauge bodies and the like.

In addition, when employing the solution polymerization method, many common organic solvents can be used, but in particular, copolymerization is carried out with less than 20% solvent added, and the solvent is not removed at all or hardly at all afterwards. Preferably, alcohol-based hydrophilic solvents such as methanol, ethanol, n-butanol, 11-propanol, isopropyl alcohol, S'eC-butanol/S, or parent groups such as hydroxyl groups, carboxyl groups, and amine groups, and water The use of oligomers or prepolymers with threads is preferred.

On the other hand, the copolymer to be synthesized has a weight average molecular weight of 10
It is necessary to set it in the range of 4 to 106, and 104
If less than 106
If it exceeds the above range, the viscosity becomes high, which interferes with the alkali treatment and makes it difficult to form a slurry-like aqueous dispersion.

In this invention, a copolymer having a specific molecular weight is contained by the method described in (-), and it contains substantially no water or flIl medium other than 0 to 20% organic solvent ( After preparing and preserving the raw materials (for which it is permissible to make a living), an alkali or alkaline aqueous solution is added to the raw materials while stirring to neutralize the raw materials.

At this time, the degree of treatment i'A+f is maintained at a constant temperature IW depending on the type and properties of the copolymer, or is generally 40 to 95 degrees.
It is ℃. Alkaline components used for neutralization include ammonia, caustic sorter, and j! ,! ``Sex Potash, etc.'')S
There is usually about 1/5 (
J ~ 2 per 3 - (at a ratio of 1゛history) The misalignment is good.

1- After the neutralization treatment as described above, continue stirring/
When water is gradually added from i, a so-called phase inversion occurs after a certain period of time, resulting in a 07/SSI type slurry water dispersion in which water forms a continuous layer and copolymer particles are dispersed therein. is generated.

Please note that depending on the combination of various conditions during the above phase inversion, hydrosyls similar to those finally obtained in this invention may be produced in the slurry water dispersion. It is outside the scope of this invention because it can be used for various purposes without requiring a treatment step using an alcohol-based hydrophilic solvent.
In order to generate hydrosyl at this stage, a very limited combination of the properties of the copolymer and the alkali neutralization conditions is required, determined empirically, but in this invention it is easy to generate it normally by the above-mentioned operation. It is characterized in that it can also hydrosilate a slurry water dispersion and perform 4Hp.

In addition, as a general tendency, there is a certain amount of unreacted unsaturated monomers used in the copolymerization in the raw materials listed in 1.
If the copolymer remains at a concentration of about 30 to 30%, if the number of acidic groups in the copolymer is relatively small, or if the degree of neutralization with alkali is low, it tends to become slurry. In addition, this change from a slurry-like water dispersion to a hydrovine can be interpreted as a change in the dispersion from white to translucent, or a change in viscosity from a low viscosity state to a high viscosity state.

In this invention, an alcohol-based hydrophilic solvent is added to the slurry water dispersion described in I-, and the mixture is stirred, particularly at high speed. As a result, the slurry-like water dispersion changes into hydrosil with a well-uniformed particle size and an average particle size of 0.01 to 0.11 mounds.

Examples of alcohol-based hydrophilic solvents include methanol, ethanol, n-butanol, 1]-furopanol, isopropyl alcohol, and sec-butanol.
Examples include S, and two or more of these may be used in combination.

Additionally, addition of an alcohol-based hydrophilic solvent;
A range of 100 to 100 weight parts is preferable.

/f, O, In producing the hydrosil described in 1-4, various additives such as adhesive f, jLj agent, softener, plasticizer, crosslinking agent, filler, coloring agent, etc. are added at any stage in the above manufacturing process. By adding it, it is possible to impart desired physical properties to hydrosil or to molded products obtained from it.

The hydrosil obtained as described in V- below has excellent long-term stability as described in 5, has good uniform film-forming ability, and can be formed into films or other molded products. In some cases, water resistance and other physical properties [Ifl] exhibit sufficiently satisfactory performance. Furthermore, in the method of the present invention, the solid content concentration of the slurry water dispersion can be adjusted at the stage of preparing the slurry water dispersion, and the same adjustment can be made by adding water after hydrosil formation, so that the solid content concentration of hydrosil can be adjusted over a wide range. It can be adjusted freely. Furthermore, the viscosity of hydrosil is, for example, 30 to 70% at 25°C when the solid content concentration is 30 to 70% by weight.
0 poise (even if the deerskin has a high solids content, the value is relatively low).

Therefore, the range of application of this hydrosil is wide, and it can be effectively used in various fields such as paints, paper, sizing agents, adhesives, adhesives, overcoating agents, exterior materials, interior materials, packaging, and films. can.

Next, practical examples and comparative examples of the present invention will be shown, but the present invention is not limited to the following practical examples.

Example 1 Acrylic tm n-butyl 5 (1, methyl methacrylate 5 (N', methacrylic l!l!3), azobisin butyronitrile 0.1 g, lauryl mercaptan 0.059
2C1 of the polymerization raw materials consisting of 5g of 5ec-butanol was charged into a 500mm fourth flask, and the flask was purged with nitrogen at 40°C for 60 minutes while stirring at 112°C.

After that, the reaction was carried out at 85°C for 4 hours while dropping the remaining Tf of the above composition from the dropping funnel over 3 hours.
However, YIj (ji: average molecule 1 total is 4.0
A copolymer of x105 (according to 01″0) was obtained.

Next, 1,/8 for the carboxyl group of this copolymer.
After adding aqueous ammonia solution (25% by weight) of this 111 and neutralizing it at a temperature of 83°C,
Co-Hi combination while stirring W 10 cities 135i1j! Re1≦
It took about 1.5 hours to drip water, and it was out of 100! When 7i parts of water was dropped, a phase inversion phenomenon occurred in which a continuous layer became water, and the final viscosity was 8.

A white slurry water dispersion exhibiting poise (25°C) was obtained.

Then, maintaining this aqueous dispersion at 83° C., 15 parts by weight of 5QC-butanol was added to the water dispersion, and the mixture was stirred for 2 hours using a high-speed 4 tl stirrer. When the mixture was stirred for 20 minutes at a rotational speed of 0 0 0 rp+n, translucent hydrosil was obtained. This hydrosil has a viscosity of 250 poise (25°C), a solids concentration of 40% by weight, and an average particle size of 0. U9/177L
(by Nanosizer).

When I investigated the stability of 1 L of this hydrosil when left unused, I found that it was 25
No sedimentation and separation of the copolymer particles was observed even after heating at 50°C. In addition, 7 5 tr71L of the 1-hydrosol
It was cast onto a thick polyester film I- and heated at 130°C.
A film with a thickness of 50/Int was formed by heating and drying repeatedly for minutes, and a sample of this film was immersed in water at 40'C.
It was found that the water absorption rate after 3 days was 12 weight and 96, and no whitening occurred even after 48 days, indicating excellent water resistance.

Comparative Example 1 A copolymer was synthesized with the same composition and under the same polymerization conditions as in Example 1, and a slurry water dispersion was prepared in the same manner as in Example 1 using this copolymer. When the storage stability of this slurry aqueous dispersion was evaluated by N1AJ, it was found that one copolymer particle sedimented after 10 days at 25°C. Further, a film was formed on polyester film-L using the above slurry water dispersion in the same manner as in Example 1, and this film was
When immersed in 'C water, the water absorption rate of 311f& was 1
It reached 5.4%] and whitening occurred after 411 days.

Comparative Example 2 The same composition as Halo Example 1 was used, and one piece of co-mercury '11 was cut under the same conditions. This J IU combination 1 I ζ -] tJ 'C for the order hat ;) Crush it, and together j7'
) body powder? It's H. This fine powder 1 tJ 11 ton L
j: Cut i'iB into 150 parts by weight of ion-exchanged water into i:i': parts J[]shi, 2. (J U (J
RPM 1 related 1] θ was carried out from O to Kyoichi I. The dispersion was divided into 11 parts in water to obtain a slurry of water. This dispersion had excellent storage stability. After 3 minutes, a sedimentation amount of 1 iHlf was produced.
Due to poor properties, film formation and film formation as in Example 1 were performed.
It was also difficult to form an o-sol.

Example 2 Acrylic] ζ・2+1-butyl 4 tJ F, methacryl 1゛1-methyl 6u9. Acrylic l tube 2. The average molecular weight was 7.1X in the same manner as in Actual bm Example 1 using polymerization raw materials consisting of LJp and Hensoil peroxyl-0,19.
1 (J5 copolymer was obtained. Next, an ammonia aqueous solution (2
5ffliTr% concentration) was added and neutralized at 83°C.
In addition, there is an extra 180 ton 1 for the copolymer iuu ton 1
A white slurry-like aqueous dispersion was obtained by adding water in a proportion that would form a hill over a period of 2 hours. This aqueous dispersion had a viscosity of 2 U poise (25°C).

The aqueous dispersion was then maintained at 83° C. and the copolymer 1 fl tJ ! ii: 5 times 1 for 1i+ part
``The methanol of the L part is 2,01J (J l'1)Il
The mixture was added with a high-speed stirring blade of 1.5 liters and stirring was continued for 20 minutes, yielding a translucent hydrosil.

This hydrosil has a viscosity of 19 tJ poise (25°C).

The solid content concentration was 34 weights, the average particle size was 0.09 μm, and both the storage stability and film properties were excellent, almost the same as in Example 1.

Example 3 Acrylic 11'22-ethylhexyl 100FI, methacrylic acid 2 (J9. Azobisisobutyronitrile 0.1
71 lauryl mercaptan 0. Polyvinyl alcohol aqueous solution 2 of 0.1% by weight M° of polymerization raw material consisting of 5g of
The mixture was stirred at 2.00 rpm and allowed to react for 5 hours. Filter the produced pearl ton and thoroughly rinse with water. After cleaning and drying, the weight average molecule U1 of the stripped copolymer was found to be 53.105. 1
1 t of ammonia water r8 ltK (25ll'i,
1. '+i,' 9o concentration) was added and neutralized at 70°C, and the copolymer 1. OO! A total of 111 or 170 tons of water was added over 1.5 hours to obtain a white slurry water dispersion. This water dispersion had a deadness of 103 poise (25°C).

(') (Then, maintain this aqueous dispersion at 83°C and then
y) 951F: Combined (a; 100 mill MS
Ic vs. m1IJS (') Isopropyl alcohol at 2,0001'Pm IIJ
When the mixture was added under pressure and stirring was continued for 20 minutes, a translucent hydrogel was formed.

This hydrovine has a viscosity of 400 poise (25°C).

Solid concentration 52 Weight 96. Average particle size 0.08 trm
With hLi, 111, the stability and film properties of Example 1 and 2 were almost unchanged.

[Row 4] A polymerization raw material consisting of 50 g of ethyl acrylic, 50 f of vinyl acetate, 50 g of methacrylic acid, benzoyl peroxide O, IV, and 200 y of ethyl acetate was placed in a flask 1e and heated at 40°C for 40 minutes with stirring. Nitrogen 11'! -1'
I changed it. Next, add Hensoil peroxide 017J
JII L, after completely dissolving, react at 60'C for 3 hours, II\h and Il uniform molecular weight) i7.8 x 105
A combination of ``noco+fi'' was synthesized. Ethyl acetate and unreacted monomer components were distilled off from this copolymer, and then an aqueous slurry dispersion was obtained in the same manner as in Example 1 using this copolymer. This aqueous dispersion had a viscosity of 72 poise. Thereafter, hydrosil was prepared in the same manner as in Example 1 using this aqueous dispersion.

The hydrosil thus obtained has a viscosity of 220 boids (at 25°C) r solid fraction IJt 39 't17
The a96° average particle diameter was 0.09 am, and the same good results as in Examples 1 and 2.3 were obtained in terms of radiation stability and film properties.

Claims (1)

[Claims] Lll +'+e Unsaturated 1 (1-i) with M group
Body 0.1-35-1li::I'+', 96 and the song Furii that can be copolymerized with this! Japanese unit (l; body 999-65
1'+', ii:' Obtained by copolymerizing with 96! '
l'T) l'l·do PH, H104-106 co-i1j1/ is added with alkali lS or alkaline aqueous 〆^ to convert -); IS or all of the hexagonal groups in the above copolymer molecules. At the same time as neutralization, a slurry-like water dispersion in which the co-r1↑tone body is dispersed in water is prepared, and an alcohol-based water-based solvent is added to the water dispersion in an amount of 0.0% to 100 parts by weight of the copolymer. By adding 1 to 100 parts by weight and stirring, the copolymer has an average particle diameter of OO1 to 0.1 tr.
A method for producing hydrosil, characterized by obtaining hydrosil stably dispersed in water within a range of m.