JPS6026003A - Production of ethylenic polymer emulsion of excellent heat resistance - Google Patents

Abstract

PURPOSE:To obtain the titled polymer emulsion stably in high yields, by emulsion-polymerizing an ethylenically unsaturated monomer by using a specified redox initiator system in the absence of a surfactant. CONSTITUTION:An ethylenic polymer emulsion excellent in heat resistance and particularly suitable as an adhesive is produced stably in high yields by polymerizing an ethylenically unsaturated monomer (e.g., ethyl acrylate) in an aqueous medium in the absence of a surfactant by using a redox initiator system comprising an oil-soluble oxidizing agent and a water-soluble reducing agent (e.g., a combination of cumene hydroperoxide with L-ascorbic acid). Although conventional emulsion-type adhesives or self-adhesive have a tendency toward showing poor resistance to heat or water because a large amount of a surfactant is used in their polymerization, the ethylenic polymer emulsion formed according to the present process is freed from this drawback because the polymerization is performed without any surfactant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an ethylenic polymer emulsicone having an excellent heat resistance of 1. Concerning the payment of 100,000 yen from the manufacturer's report.

Conventionally, solution-type adhesives and pressure-sensitive adhesives using organic solvents as a medium have been used. (111 Ushigami 1゜) From the standpoint of resource conservation, emulsion type adhesives and adhesives have been increasingly used in recent years.

However, in the case of mulsion-type adhesives and adhesives, because a surfactant containing a large amount of u4 is used during polymerization, -
'l,? I・I water P1 61 and I that the weather resistant edition is inferior
It's in the opposite direction.

In particular, when emulsion type 1 type is used as a pressure sensitive adhesive such as fine powder seam 1 or adhesive tape, it has a problem that its heat resistance is inferior to that of a solution type pressure sensitive adhesive. Therefore, conventional]
- Paste stickers, labels, hooks, etc. coated with a mullion-type adhesive on the adherend (if it is J, at room temperature -
1-4 and changes in the air grooves depending on the season, they may slip or fall from the adherend.

In addition, for general industrial purposes, such as pasting heat insulating adhesives on heat-generating parts such as air-conditioning equipment, the current situation is that the use of multi-mulsion adhesives is limited due to their poor heat resistance. be.

In order to improve the heat resistance of conventional emulsion-type adhesives, we used water-soluble radical polymerization initiators such as hydrogen peroxide and potassium persulfate in the absence of surfactants during emulsion polymerization. Polymerization 1! There are known ways to reduce it. However, when emulsion polymerization is carried out by this method, the particles in the emulsion become coarse and agglomeration between particles tends to occur during polymerization, and the yield is significantly reduced. Sex is also not something that should be fully satisfied.

As a result of various studies in order to overcome the drawbacks of the above-mentioned conventional methods, the inventors of the present invention have determined that when emulsion polymerization is carried out, a specific redox initiator is used instead of a surfactant +7I agent, or a surfactant is used. -ion f't Jlj using a specific redox initiator without using an agent
Heat resistance 1 due to the presence of 11 parts in 1Z
71 The polymer-based emulsion that has deteriorated in No. 1 is only stabilized.
) 1rj with high yield and completed the present invention.
fought against each other.

That is, the present invention 1. L, 1-bu 1 non tl + unsaturated instep f
In polymerizing 4- in water↑11 medium in the absence of interfacial agent 1-1, oil-soluble t'l anti-mildew agent solution t! l',
Heat-resistant 1/L: f
:1 Guretaoujinon1 (1 polymer) - Mulsion!
P! 13 Concerning people.

In general, the present invention provides a method for polymerizing nib 1 in the absence of surfactant P 1 in an aqueous medium.
Using a redox initiator consisting of a 'l-,1Ilf-forming agent and a water-soluble 1z1 reducing agent, heat-resistant polymerization is achieved, which is characterized by the ability to quickly polymerize θf of an indium bamboo monofilament. The present invention relates to a method for producing an ethyl non-f/I polymer emulsion.

The ethylenically unsaturated monomer that can be used in the present invention has at least 61 ethylene unsaturated bonds in its molecule, and its TI'i3- It is preferable to have a glass transition humidity of -20°C to -70°C. Typical examples include methyl acrylate, edyl acrylate, butyl acrylate,
Acrylic or methacrylic acid esters such as ocdyll acrylate, methacrylate, ethyl methacrylate, butyl tacrylate, ocdyl methacrylate, etc., hard vinyl esters such as vinyl acetate, vinyl propionate, vinyl persate, acrylic acid, Unsaturated monocarboxylic acids such as methacrylic acid, unsaturated polycarboxylic acids such as itaconic acid and maleic acid, vinyl aromatic compounds such as styrene and α-methylstyrene, vinyl chloride, vinyl bromide, etc. Examples include olefins such as vinyl halides, ethylene, propylene, and the like. These ethylenically unsaturated monomers may be used alone or in combination of two or more.

A small amount of a cross-linking agent may be added to the ethylenically unsaturated monomer, if necessary.

Examples of cross-linking agents include divinylbenzene, dipy-4-nylnatone, divinyl-toluene, etc.2) Aromatic polyvinyl compounds, 1-dylene glycol dimethacrylate, di-+11song glycol dimethacrylate, etc. Ray
1., aliphatic polyvinyl compounds similar to trimedyl 11-propane 1 to rimethacrylic 1 notes, N-methylol acrylamide, N-mesololmethacrylamide, medylol compounds similar to Kasa, glycidyl methacrylate-1
〜 etc. can be mentioned.

The redox initiator used in the present invention is oil-soluble f'J anti-distillation agent-soluble)! If it is compatible with the base agent, bJ is fine. Examples of the oil-soluble f11 oxidizing agent include per-4:rads such as benzo, yl peroxide and lauroyl peroxide, and 1-nicomenhyde [1-butylhide]1-peroxide, etc. Examples include hydroperoxides.

Water-soluble 411 reducing agents include, for example, ferrous chloride, transition metal salts such as Mohr's salt, sulfites, hyposulfites, Kuruma 1
Bad sulfoxy compounds such as ITi sulfuric acid, bad primary or secondary amines such as ethylene diamine and diethylene triamine, bad cyclic esters such as 1-ascorbic acid, tartaric acid, malic acid, etc. Nidic acid, etc. can be mentioned.

These oil-soluble oxidizing agents and water-soluble reducing agents may be suitably combined L'-
It is possible to use T, but especially Kikumenhide 1-1
It is desirable to use a redox initiator such as a combination of per-A oxide and 1-ascorbic acid, or a combination of benzoyl peroxide and ferrous sulfate.

The oil-soluble oxidizing agent is preferably used in a range of 0.1 to 2% by weight based on the ethylene t'l unsaturated monomer. Dissolves in water! 1 Yu)! When used as a main contractor, it is used in a range of 10 to 500 mol % based on the oil-soluble oxidizing agent, and preferably in a range of 50 to 200 mol %.

If the amount of oil-soluble F1 oxidizing agent used is less than 0.1% by weight based on the ethylenically unsaturated monomer, or if the amount of water-soluble reducing agent used is less than 10 mol% based on the amount of oil-soluble oxidizing agent, the polymerization rate will decrease. Not only does this result in a decrease in yield due to a decrease in yield, but also the formation of a gel, which is undesirable. On the other hand, if the use h1 of oil-soluble II oxidizing agent is more than 2% for Tdi1 non-f'l unsaturated monot6 body, or the use 111 of water-soluble 1-1 reducing agent is oil-soluble t' tPI! If the amount of the blocking agent is more than 0% relative to the lizing agent, the intermolecularity of the 0 polymer will decrease, and therefore the cohesive force of the polymer will increase by 41°C, the contact force will increase, and the shear strength will decrease. do.

Combining with a strong oil-soluble f1 reducing agent such as palmitate
Even if the polymerization is carried out in the absence of agent I, no double polymers are formed and the polymer is formed into a full-length polymer. Also, a redox initiator consisting of a water-soluble f'l oxidizing agent alone, a combination of a water-soluble oxidizing agent and a water-soluble reducing agent, or a combination of a water-soluble oxidizing agent and an oil-soluble reducing agent-1! Even when polymerization is carried out in the absence of a surfactant using a redox initiator consisting of
I can't get 1m of Mulsion.

In the method for producing the emulsion of the present invention, any of the polymerization operations carried out in conventional emulsion polymerization methods can be employed, but in order to carry out the polymerization smoothly, for example, reaction Water or water and an ethylenically unsaturated monomer are charged into a container, and the reaction container is purged with nitrogen if necessary and heated to a predetermined temperature. It is preferable to add the system initiator in its entirety at once, or to add it continuously or in portions.

The polymerization temperature varies depending on the ethylenically unsaturated monomer used, the redox initiator, the cooling capacity of the reaction vessel, etc.
Although it cannot be determined exactly, generally 30 to 90℃
It is preferable that it is in the range of .

In the present invention, heat resistance is achieved by polymerizing ethylenically unsaturated monomers in the presence of a redox initiator consisting of an oil-soluble oxidizing agent and a water-soluble reducing agent without using a surfactant. Excellent emulsions can be obtained stably at high concentrations, but if an ionic monomer is added to the polymerization system, the polymerization rate will further increase, and the stability and heat resistance of the resulting emulsions will further increase. improves.

The ionic monomers mentioned here do not exhibit surfactant-like effects on their own, and specific examples include allylsulfonic acid, meta-allylsulfonic acid, and methylnonesulfonic acid. , vinylsulfonic acid, sodium allylsulfonate, sodium metaallylsulfonate, sodium styrenesulfonate, sodium vinylsulfonate, and other sulfonated unsaturated hydrocarbon salts, 2-
Acrylamido-2-methylpropanesulfonic acid, 2-
Acrylamide-2-methylbenzene derivatives of acrylamide such as sodium pansulfonate and salts thereof, N-methyl vinyl chloride, and 2-hydroxy-3-methacryloyloxypropyl 1- Limethylammonium chloride, 2-
Examples include quaternary ammonium salts such as hydroxy-3-acryloyloxypropyl 1-limebluan[nium chloride, 2-hydroxy-3-methacryloyloxypropyltriethylammonium chloride, and the like.

For use with ionic monomers, ethylenically unsaturated monomers 1
0.1 to 2 parts by weight, preferably 0.00 parts by weight.
! i~1 part by weight. If the amount of ionic monomer used is less than 0.1 parts, the thermal stability of the emulsion may be further improved by removing the agglomerates from the polymerized nib. On the other hand, if the amount of ion t used is more than 2 parts by weight, lumps are likely to form during polymerization, and if an emulsion with 1.r < , iFj is used as an adhesive. , Water resistance of adhesive tape 1!
4 decreases, which is not preferable.

If you use a regular surfactant instead of the ionized Takenaka Reitai, it will not be heat resistant! [A cloudy emulsion cannot be sold for 1q.

The ionic suspension can be added to the aqueous medium in advance, or it can be added to the ethylenically unsaturated monomer I4. According to the present invention, a chain transfer agent such as carbon tetrachloride or mercaptan may be present as necessary to adjust the molecular weight of the polymer during polymerization.

Thus, since the ethylene f1 polymer emulsion obtained by the method of the present invention has excellent heat resistance, it is particularly suitable for adhesive sheets or adhesive tapes.
It is useful as an adhesive for a. Also, glue and 1
)-(also(r Il'l).

Hereinafter, the present invention will be further explained with reference to Examples.

Example 1 1, If iil, It'll 4'l' il
L, N A L, II Container, drop [1-1- Take etc. (t
+] In a reaction vessel with an internal volume of 3Ω, add 1.2q1 2-acrylamide-2-tar 1 pansulfonic acid sorter.
Acrylic infusion 1 = fle 2! il, and added 414Q of water.

While stirring, nitrogen was passed for 30 minutes to exchange the air in the reaction vessel with F'7. :1ν,j (1, the temperature in the reaction vessel was gradually lowered by -1°C) and the temperature in the reaction vessel was brought to 70°C.

Next, 0.5 g of a 10% aqueous solution of 1--des-1 lupic acid and 0.5 g of conomenhyde peroxide was added to the reaction vessel. After heating the inner pot of the reaction vessel to 75-80°C
2--T pool hexyl acrylate-1-32
0g, Acrylic Chu Nibble 1 GOL Divinyl Bengen 1
, 5 g and acrylic acid 90J: Lii A weight compound, 4.8 g of sodium 2-acrylamide-2-methylpropanesulfonate 113J: Bisui 40aJ: Rinarui A ↑ No 1 single skewer 11 - I Wood aqueous solution, Kimen Hydroper Δ21 Cito 1.5g
, 1--as' 10% aqueous solution of lupic acid 15! J was added dropwise over 3 hours.

After the dropwise addition was completed, the temperature was further maintained at 80°C for 1 hour. After cooling 28
% aqueous ammonia was added.

The reaction proceeded smoothly, and the resulting emulsion had a polymer concentration of 50.2% by weight, a viscosity of 120 cps (30° C., rotational viscometer, 10 rpm), and a pH of 8.

Example 2 Polymerization was carried out in the same manner as in Example 1, except that sodium 2-acrylamide-2-methylpropanesulfonate was not used. There were patches of polymer with a dry weight of 15 g on the walls and bellows during polymerization. The resulting emulsion had a polymer concentration of 48.5% by weight and a viscosity of 80 cp.
s, PH was 8.

Example 3 In Example 1, the amount of sodium 2-acrylamide-2-methylpropanesulfonate used was changed to 2.4Q for the first time.
, except that the second dose was doubled to 9.6g.
Polymerization was carried out in the same manner as in Example 1.

12- The reaction is proceeding smoothly (polymer wetness of the q emulsion is IV), 5 mfR%, viscosity is 450 cps, P l
-1 was 8.

Example 4 In Example 1, except that acrylic acid was not used,
Polymerization was carried out in exactly the same manner as in Example 1.

The reaction was smooth and the emulsion was 1% in the polymer layer.
sJ: Rikozaku, Pl-1 was 8.

Example 5 Polymerization was carried out in exactly the same manner as in Example 1, except that divinylbenzene was not used, and the mer concentration was 48.
．． 3% by weight, viscosity was 1 oocps or less, and Pl-1 was 8.

Comparative Example 1 In Example 1, 2-acrylamide-2=methylp[1 instead of sodium pansulfonate, normal surfactant
Add the same amount of the drug dodecylbene (!sulfonic acid solution)
The procedure was carried out in the same manner as in Example 1, except that the first and second additions were the same.

1r, 1 emulsion has a polymer concentration of 49.3
% by weight, viscosity was 5!10 cps, and P l-1 was 7.

Comparative Example 2 In Example 1, Kikomene hydroperoxide and L
- Using 200 g of a 10% aqueous solution of potassium persulfate, which is a water-soluble radical polymerization initiator, instead of the redoxin initiator consisting of ascorbic acid, 10 g at the start of polymerization, and the remaining 10 g for 30 minutes after starting the polymerization, Polymerization was carried out in the same manner as in Example 1, except that the addition was carried out before the completion of the addition of the 7-mer.

The resulting emulsion had a polymer concentration of 49.3% by weight.
, lk'ia IJ 210clls, P t-1
It was 8.

Next, adhesive tapes were created using the emulsions obtained in Examples 1 to 5 and Comparative Examples 1 to 2 above.

The method for making the adhesive tape is as follows: 1) Add a nonionic thickener (Adekanol U l-1-14 (l) to 100 parts by weight of the emulsion
S It! + electrification (+:L) made by Ne1) 0.2 to 1
C viscosity 4・approximately 1000 (l c p
Apply Marji 31 (adjusted to S) to the front pattern paper using an I-mil j knob retractor. An adhesive 7-book was prepared by transferring it to paper. Table 1 shows the evaluation results for the samples. I did it.

(1) Adhesion f2 t'I J, l) +IIV 20℃ (2) Adhesive strength 5tJS304. Lamination: Measured 300 after 20 minutes
mm /min 20℃ (3) Holding Horn 1 Time until f roll falls when k<1/in2 (blank below) 15- Table 1 Patent Applicant Showa Kobunshi Co., Ltd. Ne1 Agent Patent Attorney Kiku Earth Spirit - '16-

Claims (1)

[Scope of Claims] 1.] Polymerization of non-nidilonic unsaturated shells in an aqueous medium in the absence of a surfactant! Oil-soluble (IC)
M-blocking agent (water-soluble)! Polymerization 1 using a redox initiator consisting of a base material! A method for producing an ethylene f1 car combination emulsion with excellent heat resistance f/1, characterized by: 2. In polymerizing the unsaturated monohedral dilene f1 in the absence of a surfactant in a water medium, a monodoxic initiator consisting of an oil-soluble oxidizing agent and a water-soluble ↑11 reducing agent was used. A method for producing Eblen t'1 polymer emulsion 1 based on heat-resistant fz1, which involves polymerizing Ant'111f in the presence of the same material.