JPH0241338A - Antifoaming agent for polymer latex - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides an antifoaming agent for polymer latex which contains as an essential component one or more mono-, di- and trialkanolamine salts of higher fatty acids having 14 to 22 carbon atoms. Regarding.

[Conventional technology]

When producing synthetic rubber latex such as SBR, NOR, or polymer emulsion (hereinafter collectively referred to as polymer latex) such as vinyl acetate, vinyl acetate-ethylene, or alkyl (meth)acrylate, or after producing polymer latex. Foaming problems occur when recovering monomers and when blending and mixing polymer latex for various uses. For this reason, it is known to use antifoaming agents in order to smooth the manufacturing process of polymer latex or the blending process for various uses (Japanese Patent Application Laid-open Nos. 62-49939, 47-42588, etc.). ).

Conventionally, mineral oil, higher alcohol, wax emulsion, silicone resin, polyoxyethylene polypropylene glycol, polyalkylene glycol, etc. have been used as such antifoaming agents, but depending on the type of foam generated, the effectiveness may be insufficient. Problems have been pointed out such as the polymer latex may not be suitable for use, and furthermore, the storage stability of the polymer latex is poor and the film performance is deteriorated.

(Problems to be Solved by the Invention) An object of the present invention is to provide an antifoaming agent that has an extremely good antifoaming effect and can also stably maintain the original performance of polymer latex.

[Means to solve the problem]

According to the present invention, there is provided an antifoaming agent for polymer latex, which contains as an essential component one or more of mono-, di-, and trialkanolamine salts of higher fatty acids having 14 to 22 carbon atoms.

The mono-, di-, and trialkanolamine salts of higher fatty acids which are essential components of the antifoaming agent for polymer latex of the present invention are characterized in that they are mono-, di-, and trialkanolamine salts of higher fatty acids having 14 to 22 carbon atoms. , preferably a trialkanolamine salt of a higher fatty acid having 16 to 20 carbon atoms, particularly preferably a triethanolamine salt of a higher fatty acid having 18 to 20 carbon atoms.

If the number of carbon atoms in the higher fatty acid is less than 14, the water solubility will be high and the antifoaming effect will be reduced, and if the number of carbon atoms is more than 22, the water solubility will be extremely low and the antifoaming effect will be poor, which is not preferred. In addition, salts other than mono-, di-, and tri-alkanolamine salts, such as alkali metal salts and ammonium salts, have rather weak foaming properties and have no antifoaming effect, and alkaline earth metal salts are insoluble in water and have no antifoaming effect. Without this, the intended purpose of the present invention cannot be achieved.

That is, the antifoaming agent for polymer latex of the present invention has 1 carbon number.
It is characterized by having at least one type of mono-, di-, and trialkanolamine salts of higher fatty acids of 6 to 22 as an essential component, and even if it is added before emulsion polymerization when preparing polymer latex, it will not affect the polymer after production. Even when added to latex, it exhibits a good antifoaming effect.

The amount of the antifoaming agent of the present invention added is 0.001 to 2.0% by weight, preferably 0.005 to 0.0% by weight, based on the polymer latex.
．． It is 5% by weight, more preferably 0.01 to 0.3% by weight.

Since the antifoaming agent for polymer latex of the present invention is a solid or highly viscous material, in order to facilitate its handling, it preferably contains water, lower alcohols such as methanol, ethanol, and isopropyl alcohol, ethylene glycol, etc.
It is desirable to use a solubilizing agent such as glycols such as diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, and polyoxypropylene polyethylene glycol in combination to liquefy the product.

〔Effect of the invention〕

The antifoaming agent for polymer latex of the present invention has 14 to 14 carbon atoms.
Because it contains one or more of the mono-, di-, and trialkanolamine salts of 22 higher fatty acids as an essential component, unlike conventional antifoaming agents for polymer latex, it is compatible with synthetic rubber latex such as SBR and NBR, vinyl acetate, and acetic acid. When recovering monomers during and after the production of polymer emulsions such as vinyl-ethylene, (meth)acrylic acid alkyl esters, vinyl chloride, vinylidene chloride, and styrene, and when recovering monomers such as these synthetic rubber latex or polymer emulsions. When blending and mixing with pigments, fillers, fine aggregates, cement, etc. to prepare paints, polymer cement mortar (concrete), etc., it not only suppresses foaming problems, but also improves its storage stability. , furthermore,
The original performance of the films formed by these synthetic rubbers and latexes can be stably maintained over a long period of time.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 (Preparation of polymer latex) In a glass reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, a nitrogen introduction tube, and a dropping funnel, sulfuric acid ester of ethylene dodecyl ether (EOP=5) was added as an emulsifier. 12.0 parts by weight and 150 parts by weight of water,
The mixture was dissolved and the inside of the system was replaced with nitrogen gas.

Separately, 150 parts of an unsaturated monomer mixture consisting of 90 parts by weight of acrylic acid and 60 parts by weight of methyl methacrylate was prepared, and 5 parts by weight of these were added to the reaction vessel and heated at 40°C.
Emulsification was performed for 30 minutes. Next, after raising the temperature to 70°C, 2,2'-azobis(N,N'-dimethyleneisobutyramidine) hydrochloride was added to 9. OX 10-3moQe
/ aqueous phase in 50 parts of water and added to the reaction vessel, and immediately the remaining unsaturated monomer was continuously dropped into the reaction vessel over 30 minutes, and 60~ 65
Emulsion polymerization was carried out at ℃. After finishing dropping the unsaturated monomer, 6
A polymer latex was prepared by aging at 0 to 65°C for 60 minutes.

(Performance evaluation of antifoaming agent) The solid content concentration of the polymer latex thus obtained was adjusted to 20% by weight, 50g was placed in a 10100O diposa cup, antifoaming agent 20- shown in Table 1 was added, and Mixer (Toshiba hand mixer H 300 (R)
)) After stirring for 30 seconds at a beater rotation speed of 970 rpm, the polymer latex foaming liquid was immediately transferred to a too+72 graduated cylinder, and the foam amount was measured over time.

Regarding the antifoaming agents of Samples &2 to 8, which are examples of the present invention, and Samples Nnl and 9, which are comparative examples, the following composition was used as the antifoaming agent in order to liquefy the antifoaming agent. there was.

(Evaluation of standing stability) 100 g of polymer latex whose solid content concentration was adjusted to 20% by weight and 40 d of the antifoaming agent shown in Table 1 were uniformly placed in a 150-sized glass bottle and the bottle was tightly capped.

The polymer latex was left standing in a constant temperature room at 45° C. for one month, and the standing stability of the polymer latex was evaluated by the following method.

0: Average particle diameter of polymer latex immediately after preparation (manufactured by Coulter Electronics, USA).

Coulter Submicron Particle Analyzer Coulte
(Model N4 type used) and the average particle diameter of the polymer latex after being left standing with an antifoaming agent added are almost the same, and the layer separation of the polymer latex.

There is no agglomerated precipitate, and the polymer latex shows the same antifoaming performance as immediately after adding the antifoaming agent.

Δ: There are some aggregates in the lower layer of the polymer latex,
The performance of the antifoaming agent is 20% or more lower than immediately after the addition of the antifoaming agent.

×: There was layer separation in the polymer latex, and the performance as an antifoaming agent was lost.

(Performance evaluation of film characteristics) Solids were reduced to 20% by weight, and 30 g of polymer latex was added to 12 m after adding antifoaming agent additive and standing for 1 month.
It was uniformly cast on a glass plate of 14 countries and air-dried at room temperature.

A film was formed, and the transparency and gloss of the film were evaluated according to the following criteria.

Transparency: The haze value of the film was measured using an integral light transmittance measuring device according to JIS K6714.

Glossiness: Specular glossiness was measured at 60°C according to JIS 28741.

The performance as an antifoaming agent was evaluated using the above method. The results are shown in Table-1.

Samples &2 to 8 are examples of the present invention, and it can be seen that the antifoaming agent of the present invention has a good foam-inhibiting effect and does not affect the inherent performance of the polymer latex. In addition.

Samples N (kl, 9 to 12 are comparative examples).

Example 2 8.0 parts by weight of the cationic emulsifier shown in Example 2, 0.02 parts by weight of stearic acid, 0.01 parts by weight of triethanolamine (neutralization equivalent) and 150 parts by weight of water were added to a reaction vessel in the same manner as in Example 1. Prepare and perform emulsion polymerization in the same manner as in Example 1,
A polymer latex was obtained.

There was no foaming during emulsion polymerization and aging, and the polymer latex was adjusted to have a solid content of 20% by weight.
In the same manner as in Example 1, the performance as an antifoaming agent, the standing stability as a polymer latex, and the film properties were evaluated.

The results were: foam volume immediately after 50-1 foam volume after 130 seconds 0-1 static stability: o, transparency: 2.1 (3.0 after 1 month), gloss: 'J5 (93 after 1 month) ) and showed good results as an antifoaming agent.

Example 3 Similarly to Example 1, ethylene-vinyl acetate polymer emulsion (EVA; Nippon Kasei NS Hiflex H)
F-100) Primary antifoaming agent composition using SBR (Tomax Stopper manufactured by Nippon Latex) Higher fatty acids (C□s/Cxe”3/7 weight ratio); 15% by weight triethanolamine; Neutralization equivalent of fatty acid isopropyl Alcohol: 35% by weight polyoxypropylene polyoxyethylene water: Using balance, performance as an antifoaming agent, static stability as a polymer latex, and film properties were evaluated in the same manner as in Example 1. .The results were all good.

Patent applicant: Lion Co., Ltd.

Claims (1)

[Claims] (1) An antifoaming agent for polymer latex, characterized in that it contains as an essential component one or more of mono-, di-, and trialkanolamine salts of higher fatty acids having 14 to 22 carbon atoms.