JPH02120385A - Foaming agent - Google Patents

Abstract

PURPOSE:To obtain a foaming agent which is nonflammable, does not generate toxic gas, and shows improvements in dispersibility in rubber, etc., foaming effect, and stability by (co)polymerizing a specified polymerizable tert-butyl ester of an unsaturated carboxylic acid and, if necessary, other monomer. CONSTITUTION:30wt.% or more of at least one monomer (A), i.e., at least one polymerizable tert-butyl ester of an unsaturated carboxylic acid, selected from a polymerizable tert-butyl ester of an unsaturated monocarboxylic acid, a polymerizable mono-tert-butyl ester of an unsaturated dicarboxylic acid, and a polymerizable di-tert-butyl ester of an unsaturated dicarboxylic acid, (e.g., di-tert-butyl fumarate) is (co)polymerized with 0-70wt.% monomer (B) other than component A (e.g., methyl methacrylate) in the presence of an initiator to give a foaming agent. This foaming agent, after being mixed with an aqueous resin dispersion or an aqueous resin solution if necessary, is applied to or incorporated into a material to be expanded, which is heated at 120-250 deg.C, preferably 150-200 deg.C, to effect foaming.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides the following advantages:
Foaming ink, foaming printing agent 1 foaming adhesive.

Foaming paints, foamed polystyrene, foamed polyolefin used for foamed electric wires, etc., foamed polyvinyl chloride used for flooring, wallpaper, etc., foamed EV
A. It relates to a blowing agent that is itself a polymer and is used in plastic foams and rubber foams such as foamed ABS, foamed modified PPO, foamed natural rubber 1 foamed SBR, foamed CR, and foamed EPDM.

(Conventional technology) Traditionally used as a foaming agent for rubber, plastic, etc.

Azocica-bonamide, dinitropentamethylenetetramine, p-toluenesulfonylhydrazide, p, p'~
In addition to oxybis (benzenesulfonyl hydrazide), microencapsulated organic fusing is used.

Azocicabonamide is an excellent blowing agent in many respects, such as 1) dispersion, 1) calorific value, self-extinguishing properties, and its own sanitary properties (1) decomposition temperature, but it has the drawback of generating -carbon oxide gas when decomposed. .

Dinitropentamethylenetetramine is a highly flammable substance and has the dangerous property of decomposing and igniting even at room temperature when it comes into contact with mineral acids.

Although p-toluenesulfonyl hydrazide is excellent in various respects as a foaming agent for rubber, particularly as a co-foaming vulcanizing agent for rubber, it has the disadvantage of having a low decomposition point (around 105° C.).

p,p'-oxybis(benzenesulfonyl hydrazide) has excellent stability, such as non-staining, non-coloring, and odorless decomposition residue, but has the disadvantage of poor dispersibility in rubber and plastics. Ta.

Furthermore, microencapsulated organic solvents are flammable. Since the capsule wall is easily destroyed by pressurization, the process of mixing the blowing agent is complicated and the applications are limited.

In addition, these foaming agents can be mixed with an aqueous resin dispersion or an aqueous resin solution to create an aqueous two-foaming ink.

Even if an attempt was made to obtain a foamable printing agent, a foamable adhesive, a foamable paint, etc., the dispersibility of the foaming agents was poor and a uniform foam could not be obtained.

(Problems to be Solved by the Invention) The present invention improves the above-mentioned various drawbacks of conventional blowing agents, and has good dispersibility in rubber and plastics.

It has excellent stability, is non-flammable, does not generate toxic gas when decomposed, and has a large foaming effect. It provides a novel blowing agent that is itself a polymer, and furthermore
When the above blowing agent is an aqueous dispersion or an aqueous solution,
Not only can it be used as a water-based foaming ink, a foaming printing agent, a foaming adhesive, and a binder for these, but it can also be used as a foaming agent when mixed with an aqueous resin dispersion or aqueous resin solution. The object of the present invention is to provide a foaming agent that has good dispersibility and can produce a uniform foam.

[Configuration of the invention].

(Means for Solving the Problems) The present invention provides tert-butyl dipolymerizable unsaturated monocarboxylate, monotert-butyl polymerizable unsaturated dicarboxylate, and ditert-butyl polymerizable unsaturated dicarboxylate. Polymerization or copolymerization of 30% by weight or more of one or more selected tert-butyl unsaturated carboxylic acids and 0 to 70% by weight of monomers other than tar t-butyl polymerizable unsaturated carboxylic acids. It is a polymer foaming agent made of The present invention also includes: The above blowing agent is an aqueous dispersion or an aqueous solution.

In the present invention, monopolymerizable unsaturated monocarboxylic acid terL
-Butyl is tert- of polymerizable unsaturated monocarboxylic acids such as (meth)acrylic acid or its substituted products.
It is a butyl ester. Polymerizable unsaturated dicarboxylic acid mono-tert-butyl includes maleic acid, fumaric acid,
Monotert of polymerizable unsaturated dicarboxylic acids such as crotonic acid, isocrotonic acid, itaconic acid or substituted products thereof
The di-tert-butyl 9-polymerizable unsaturated dicarboxylic acid which is a -butyl ester is the di-tert-butyl ester of the above polymerizable unsaturated dicarboxylic acid. Among these, it is preferable to use tert-butyl (meth)acrylate because it increases the polymerization rate and improves the stability of 8-polymerization.

Polymerizable unsaturated tert-butyl carboxylate can be polymerized alone to form the blowing agent of the present invention, or copolymerized with other polymerizable unsaturated tert-butyl carboxylate to form the blowing agent of the present invention. Monopolymerizable unsaturated carboxylic acid tert-
Monomers other than butyl and 9-polymerizable unsaturated carboxylic acid ter
The content of t-butyl is 30% by weight or more, preferably 5% by weight.
The blowing agent of the present invention may be prepared by copolymerizing the foaming agent in an amount of 0% by weight or more. A monomer of polymerizable unsaturated carboxylic acid tert-butyl and a monomer other than polymerizable unsaturated carboxylic acid tert-butyl are combined into monopolymerizable unsaturated carboxylic acid tert-butyl.
If copolymerization is carried out in a range where the content of t-butyl is less than 30% by weight, the foaming properties of the resulting copolymer as a blowing agent will be low (as well as the foaming will be non-uniform, and other resins may When foaming is carried out by adding the above-mentioned polymerizable unsaturated material, a large amount of the copolymer must be used to obtain a suitable foam, which adversely affects the performance of the resulting foam. Monomers other than tert-butyl carboxylate include (meth)acrylic acid, maleic acid, fumaric acid, and crotonic acid.

Polymerizable unsaturated carboxylic acids such as isocrotonic acid and itaconic acid, polymerizable unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride, methyl (meth)acrylate,
(meth)ethyl acrylate, (meth)acrylic acid n-
Butyl, 5ec-butyl (meth)acrylate.

Polymerizable unsaturated carboxylic acids such as 2-ethylhexyl (meth)acrylate and dodecyl (meth)acrylate
(meth)acrylic acid alkyl ester other than t-phthyl, 2-hydroxyethyl (meth)acrylate.

(Meth) such as hydroxypropyl (meth)acrylate
Examples include acrylic acid hydroxyalkyl ester, (meth)acrylamide, N-methylol (meth)acrylamide, acrylonitrile, styrene, alkylstyrenes such as α-methylstyrene, and vinyl acetate. The above polymerizable unsaturated carboxylic acid tert-butyl and monomers other than these used as necessary are prepared by a conventional method, that is, an azo initiator such as azobisisobutyronitrile, Suspension polymerization in the presence of an oxide initiator or a redox initiator that is a combination of the above peroxide initiator and a reducing agent,
Emulsion polymerization.

It is polymerized or copolymerized by solution polymerization or bulk polymerization and is used as the blowing agent of the present invention. When using the blowing agent of the present invention in combination with an aqueous resin dispersion or an aqueous resin solution,
Easy to mix and uniform mixing is possible.

Since uniform foaming can be achieved, it is preferable to use a foaming agent obtained by emulsion polymerization or solution polymerization in a solvent containing water as a main component.

The foaming agent of the present invention thus obtained may be used as a foaming ink by adding other resins, dyes, pigments, inorganic fillers, adhesion promoters, leveling agents, and other additives as necessary. 9 Printing on a printing medium such as paper, film, foil, etc. 1
When used as a foamable printing agent, it is printed on a printing object such as woven fabric or nonwoven fabric, and when used as a foaming adhesive, it is applied to the object to be adhered.

When used as a foaming paint, apply it to the object to be coated.

Alternatively, it can be added to rubber or plastic to give 120 to 25
Foaming is carried out by heating to 0°C, preferably 150 to 200°C.

(Function) Possible mechanisms for foaming the blowing agent of the present invention include: (1) decomposition of a tert-phthyl group into isobutyne; (1) decomposition of a blowing agent polymer into a low molecular weight volatile substance;

(Example) The present invention will be explained below with reference to Examples. In example.

Parts represent parts by weight, and 1% represents % by weight, respectively.

Example 1 DiLert-butyl fumarate 40.0 parts Methyl methacrylate 60.0 parts Benzoyl peroxide 2.0 parts Polyvinyl alcohol (degree of saponification 98% 1 degree of polymerization approximately 2000) 1.0 part Water 2
00. O Part The mixture having the above composition was stirred at a rotational speed of 2 through the stirring hole.
Suspension polymerization was carried out at 80° C. for 3 hours while stirring at 50 rpm to obtain an aqueous slurry of a polymeric blowing agent, and the obtained aqueous slurry of a polymeric blowing agent was sufficiently washed with water and dried at room temperature for 7 days. A spherical foaming agent with an average particle diameter of 200 μm was obtained.

When the obtained foaming agent was heated at 180° C. for 3 minutes, it foamed uniformly to about 70 times the size (volume ratio).

Comparative Example 1 A spherical blowing agent with an average particle diameter of 200 μm was prepared in the same manner as in Example 1, except that the amount of di-tert-butyl fumarate was 25.0 parts and the amount of methyl methacrylate was 75.0 parts. Obtained.

When the obtained blowing agent was heated at 180°C for 3 minutes,
Although it expanded to an average size (volume ratio) of 5 times 'Xy, the foaming was uneven and there were 9 parts where no foaming occurred at all.

Example 2 methacrylic acid t instead of di-tert-butyl fumarate
A spherical foaming agent was obtained in the same manner as in Example 1 except that er L-butyl was used, and when heated in the same manner as in Example 1, it was uniformly foamed to about 50 times the size (volume ratio). .

Comparative Example 2 A spherical foaming agent was obtained in the same manner as in Comparative Example 1, except that tert-butyl methacrylate was used instead of di-tert-butyl fumarate, and heated in the same manner as in Comparative Example 1. It expanded to about 3 times the size (volume ratio) on average, but 2 foaming was uneven and 1 part was not foaming at all. I got hit twice.

Examples 3 to 5 and Comparative Example 3 iIL polymer mixture having the composition shown in Table 1 300.0 parts Sodium dodecylhenzenesulfonate 5.0 parts Polyethylene glycol nonylphenyl ether (ethylene glycol 20 mol) 5.08B Water
689.5 parts Ammonium persulfate 0.5 parts By batch emulsion polymerization, a mixture having the above composition was subjected to emulsion polymerization at 70° C. for 3 hours to obtain an aqueous resin dispersion.

Each of the obtained aqueous resin dispersions was dried at room temperature for 7 days to obtain a powder or film foaming agent, and the foaming ratio (volume ratio) and foaming when the resulting foaming agent was heated at 180 ° C. for 3 minutes. The uniformity is also shown in Table 1.

Table 1゜Example 6゜Blowing agent obtained in Example 3 20.0 parts Aqueous acrylic resin dispersion [Torcryl N-340j (trade name, manufactured by Toyo Ink Manufacturing ■), solid content 40V6゜p H7,5
, viscosity 100 cP) 80.0 parts Aqueous pigment dispersion RWS Blue 2G-3J (trade name, manufactured by Toyo Ink Mfg. ■) 4.0 parts An aqueous foaming printing agent having the above composition, 1
Screen printed on cotton knit using a 00 Me Noche screen, pre-dried for 2 minutes at 170 °C,
The mixture was foamed by heating at ℃ for 2 minutes. Unlike aqueous printing agents that use conventional microcapsule-type foaming agents, the above-mentioned aqueous foaming printing agents do not cause clogging during screen printing.
The workability is extremely good, and the foamed prints obtained are also 1
Since the foaming was uniform, there was no unevenness on the surface, and the texture and texture were very good.

〔Effect of the invention〕

The present invention has good dispersibility in rubber and plastics,
It has excellent stability, is non-flammable, does not generate toxic gas when decomposed, and has a large foaming effect.

New blowing agents are now available which are themselves polymers. In addition, when the foaming agent of the present invention is an aqueous dispersion or an aqueous solution, it can be used as an aqueous foaming ink,
Foaming printing agent 5 Foaming adhesive 9 Foaming paint or a binder for these as well as a foaming agent with good dispersibility and uniform foam even when mixed with an aqueous resin dispersion or resin aqueous solution is obtained.

Claims (1)

[Scope of Claims] 1. One or two selected from the group consisting of polymerizable unsaturated mono-tert-butyl monocarboxylate, mono-tert-butyl polymerizable unsaturated dicarboxylate, and di-tert-butyl polymerizable unsaturated dicarboxylate; 30% by weight or more of tert-butyl polymerizable unsaturated carboxylic acid, and 0 to 30% by weight of monomers other than the tert-butyl polymerizable unsaturated carboxylate mentioned above.
A polymeric blowing agent made by polymerizing or copolymerizing 70% by weight. 2. The blowing agent according to claim 1, wherein the blowing agent is an aqueous dispersion or an aqueous solution.