KR20000031781A - Foaming agent composition - Google Patents

Abstract

PURPOSE: A foaming agent composition is provided which has an improved fluidity, load solidification characteristics and aging solidification characteristics. CONSTITUTION: 0.05-10 weight % of glycerin tri-12-hydroxy stearate (formula 1) is dispersed in chemical foaming agent such as azodicarbonamide, p,p-oxybisbenzene sulfonyl hydrazide, benzene sulfonyl hydrazide, sodium bicarbonate or sodium carbonate. Thus, 100 weight parts of azodicarbonamide and 0.5 weight part of glycerin tri-12-hydroxystearate are mixed at room temperature, for 10 minutes in the condition of 1,000 rpm to give the title foaming composition.

Description

Blowing agent composition

The present invention relates to a foaming agent composition, and more particularly, to a foaming agent composition having excellent foaming ratio and excellent flow characteristics, load solidification characteristics, and hardening characteristics.

Known chemical foaming agents such as azodicarbonamide, p, p-oxybis (benzenesulfonylhydrazide), dinitrosopentamethylenetetramine (DPT), p-toluenesulfonylhydrazide and benzenesulfonylhydrazide Polyethylene, polypropylene, ethylene-vinylacetate copolymer (EVA), polyvinyl chloride, styrene-butadiene rubber, thermoplastic resins such as acrylonitrile-butadiene rubber, and the like have been widely used as blowing agents. The chemical foaming agents are excellent blowing agents, in which the generation of nitrogen gas by heating and the decomposition products are not only nonflammable but also nontoxic. However, the chemical foaming agents have a problem in that the deterioration in quality occurs when the storage stability and / or the shelf life after the production is long due to poor storage stability. That is, the chemical foaming agents are usually in a fine powder form, but the storage stability and / or the uniformity of foaming are poor due to poor storage stability such as the aggregation of the powder gradually progresses and the dispersibility in the resin decreases with the passage of time in the storage and / or distribution stage. This becomes bad.

In order to solve this problem, conventionally (1) a method of adding an antimicrobial solidifying agent in the form of inorganic particles, (2) a method of increasing the particle size of the chemical foaming agent, and (3) a drying method of the chemical foaming agent are applied in a batch manner. Methods of reducing moisture are known.

However, these methods have several other problems. That is, the method of (1) has no problem in the foaming of polyvinyl chloride, but when foaming polyolefin-based resins such as polyethylene and polypropylene, there are problems such as adversely affecting foam quality, crosslinking, foam manufacturing equipment, and the like. In the method of (2), the quality of the foaming agent, the foaming conditions, the foam quality, etc. are greatly influenced by the particle size of the foaming agent. In addition, since the method of (3) is a batch type rather than a continuous type, it takes a long time to dry, and thus there is a problem of lowering productivity.

Accordingly, the technical problem to be achieved by the present invention is to provide a foaming composition having improved flow characteristics, load solidification characteristics, hardening characteristics without affecting the foaming performance in order to solve the above problems.

In order to achieve the above technical problem, the present invention provides a foaming agent composition comprising 0.05 to 10 wt% of glycerin tri 12-hydroxystearate based on the weight of the chemical foaming agent and the chemical foaming agent.

In the foaming agent composition according to the present invention, the metal oxide may further comprise 0.05 to 1% by weight based on the weight of the chemical foaming agent.

In the foaming agent composition according to the present invention, the metal hydroxide may further comprise 0.05 to 1% by weight based on the weight of the chemical foaming agent.

In the blowing agent composition according to the present invention, the metal element or the metal element in the metal hydroxide is preferably at least one selected from the group consisting of Si, Al, Ti, and Zn.

In the foaming agent composition according to the present invention, the glyceride of any one or more fatty acids selected from the group consisting of 12-hydroxystearic acid, dihydroxystearic acid, and stearic acid based on the weight of the chemical foaming agent further comprises 0.01 to 2% by weight can do.

In the blowing agent composition according to the present invention, the chemical blowing agent is azodicarbonamide, p, p-oxybisbenzenesulfonylhydrazide, dinitrosopentamethylenetetramine, p-toluenesulfonylhydrazide, benzenesulfonylhydra It is preferably at least one selected from the group consisting of a jide, sodium bicarbonate, and sodium carbonate.

The present invention is characterized by providing a chemical foaming agent composition having excellent flow characteristics, load solidification characteristics, and hardening characteristics by dispersion-mixing glycerin tri 12-hydroxystearate in a known chemical foaming agent.

The chemical foaming agent used in the foaming agent composition according to the present invention is not particularly limited and any known powdery chemical foaming agent may be used. For example, azodicarbonamide (ADCA), p, p-oxybis (benzenesulfonylhydrazide) (OBSH), dinitrosopentamethylenetetramine (DPT), p-toluenesulfonylhydrazide, benzenesul Ponylhydrazide, sodium hydrogen carbonate, sodium carbonate and the like can be used in the blowing agent composition of the present invention.

The chemical foaming agent used for the foaming agent composition of this invention can be used individually by 1 type or in mixture of 2 or more types. Although the average particle diameter of a chemical foaming agent is not specifically limited, It is preferable to use the particulate chemical foaming agent about 1-50 micrometers normally.

The blowing agent composition of the present invention may include a compound containing a metal element such as Zn, Pb, Cd, Cr and urea or urea-based compounds for the purpose of lowering the decomposition temperature of the blowing agent and improving the reaction rate. In addition, the foaming agent composition of the present invention contains unsaturated polybasic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid for the purpose of inhibiting decomposition and the like, various resin stabilizers, pigments such as carbon black, titanium oxide, Fillers, such as calcium carbonate, antioxidants, etc. can be foamed as needed.

Glycerin tri 12-hydroxystearate, which is dispersed and mixed in the blowing agent composition of the present invention, is represented by the general formula (1) and has a hydroxyl group in its molecular structure, and thus has a high melting point among glycerides.

In the foaming agent composition according to the present invention, the effect of the present invention can be achieved by dispersing and mixing only glycerin tri 12-hydroxystearate in the chemical foaming agent, but if it further contains a metal oxide and / or a metal hydroxide, fluidity and load solidification It has been found that the properties and hardening properties are further improved. At this time, the content of the metal oxide or metal hydroxide is preferably adjusted to 0.05 to 1% by weight based on the weight of the chemical foaming agent. If the content of the metal oxide or metal hydroxide is less than 0.05% by weight, the effect of adding them is insignificant. If the content of the metal oxide or metal hydroxide is more than 1% by weight, the effect of increasing the manufacturing cost of the foaming agent composition is no longer increased. The metal element or the metal element in the metal hydroxide is preferably at least one selected from the group consisting of Si, Al, Ti, and Zn in terms of effectively improving the fluidity, load solidification characteristics and hardening characteristics.

The blowing agent composition according to the present invention further comprises a glyceride of any one or more fatty acids selected from the group consisting of 12-hydroxystearic acid, dihydroxystearic acid, and stearic acid for the purpose of enhancing the releasability of the foam based on the weight of the chemical foaming agent. Can be. At this time, the content of the glyceride of any one or more fatty acids selected from the group consisting of 12-hydroxystearic acid, dihydroxystearic acid, and stearic acid is 0.01 to 2% by weight. If the content of the glyceride is less than 0.01% by weight, the effect of improving releasability is insignificant, and if it exceeds 2% by weight, there is a problem in that pinholes are excessively formed on the foam surface.

The method for dispersing and mixing the glycerin tri 12-hydroxystearate into a chemical foaming agent is not particularly limited, and known methods such as dry and wet methods, which are conventional mixing methods, can be used. The dry method is a method of adding glycerin tri 12-hydroxystearate or a solution thereof (dispersion) to the chemical foaming agent powder while stirring and / or preheating as necessary. Stirring and mixing are done using a conventional mixer, and preheating and warming should be done in a temperature range where no decomposition of the chemical foaming agent occurs. The wet method is a method in which a chemical foaming agent and a solution or dispersion of glycerin tri 12-hydroxystearate are mixed with each other and then dried. Glycerin Tri 12-hydroxystearate is chloroform. In a mixed solvent of tetrahydrofuran (THF), chloroform (60) / butyl alcohol (40), organic solvent or mixed organic solvent which does not react with chemical foaming agents such as n-hexane, toluene, xylene, isopropanol, methanol, ethyl acetate Use by dissolving or dispersing. Chloroform in particular among them. Preferred are mixed solvents of tetrahydrofuran (THF) and chloroform / butyl alcohol. In this case, the amount of glycerin tri 12-hydroxystearate used can be appropriately selected in a wide range without particular limitation in order to cope with the aging degree of the chemical foaming agent. As a result of various studies, 0.05 to 10% by weight is preferable based on the weight of the chemical foaming agent, and more preferably 0.1 to 1% by weight. If it is less than 0.05 weight%, it is difficult to exhibit the desired effect of this invention, and even if it exceeds 10 weight%, since the effect of this invention will not increase any more, it is uneconomical to increase the usage-amount more. In order to separate the chemical foaming agent treated with glycerin tri 12-hydroxystearate in this way, methods such as filtration, centrifugation and decantation can be used. In addition, when the chemical foaming agent is aggregated during drying, a grinding process may be added.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to the following Examples. On the other hand, in the following examples, unless otherwise stated, percentages and mixing ratios are based on weight. In Examples and Comparative Examples of the present invention, performance evaluation for the blowing agent composition was carried out by the following method.

(1) solidification test

1 kg of the foaming agent composition sample was filled into a 30 cm × 20 cm plastic bag and thoroughly degassed. Subsequently, the opening of the said plastic bag was sealed, and the load of 0.1 kg / cm <2> was applied. After two weeks, the sample was taken out and passed through a mesh of 100 mesh, and then the amount that failed to pass was measured and converted into% to obtain a solidification test value.

(2) real packing solidification test

25 kg of blowing agent composition sample was packed into a real product packaging bag and completely degassed. Subsequently, after sealing the opening part of the said packaging bag, it was left to stand on conditions of temperature 40 degreeC and humidity 80% for 1 month. The sample is then taken out and passed through a mesh of 100 mesh to determine the amount of passage that cannot pass, and then converted to% to obtain the actual packaging solidification test value.

(3) angle of repose

The angle of repose of the foaming agent composition sample was determined using a powder tester (Model PT-N manufactured by Hosokawa Micron Co., Ltd.). The angle of repose is one of the indicators of the friction characteristics or fluidity of the powder, and means the angle formed by the free-falling powder surface with the horizontal plane. Smaller angle of repose means better fluidity.

(4) decomposition temperature

The decomposition temperature of the foaming agent composition sample was measured by the capillary method using the decomposition temperature spectrometer. The temperature increase was measured on condition of 100 degreeC-3.3 degreeC / min.

(5) expansion ratio

Samples of the foaming agent compositions of Examples 1 to 4 and Comparative Example 1 below, wherein the chemical foaming agent is ADCA, were prepared according to the formulation examples a and the formulation b of Table 1 below, and were made from low density polyethylene (manufactured by Hanwha General Chemical Co., Ltd., product no. After kneading at 120 ℃ and foamed at 220 ℃. The maximum value in foaming ratio at this time was compared. The expansion ratio is defined as the density of the unfoamed material plastic divided by the density of the plastic after foaming. On the other hand, the foam press mold was 200 mm x 200 mm x 2 mm in size.

Formulation Example a Formulation Example b Low density polyethylene 100 parts by weight 100 parts by weight Blowing agent composition 20 parts by weight 20 parts by weight Dicumylperoxide (DCP) 1 part by weight 1 part by weight Zinc oxide - 0.5 parts by weight

Examples 1 to 6 and Comparative Examples 1 to 2

Chemical foaming agents used in this Example and Comparative Example were used as follows.

ADCA: Azodicarbonamide (Dongjin Hwasung Co., Ltd., product number: UNICELL ACX-01, Average particle size 20㎛)

OBSH: p, p-oxybisbenzenesulfonylhydrazide (Dongjin Chemical Co., Ltd., product number: UNICELL-OHW2, average particle diameter 6㎛)

DPT: dinitrosopentamethylenetetramine (Dongjin Chemical Co., Ltd., product number: UNICELL-G, average particle diameter 25㎛)

Example 1

100 parts by weight of ADCA and 0.5 parts by weight of glycerin tri 12-hydroxystearate (Baker Castor Oil, product number: MP-80) were added to a high speed mixer at room temperature for 10 minutes at room temperature and 1000 rpm. Thus, a blowing agent composition was prepared.

Example 2

100 parts by weight of ADCA was added to a high speed mixer, and 0.5 parts by weight of glycerin tri 12-hydroxystearate (homologous) was heated to 85 ° C. and then melted and sprayed, followed by mixing for 10 minutes at room temperature and 1000 rpm. A blowing agent composition was prepared.

Example 3

100 parts by weight of ADCA was added to a high speed mixer, and 0.5 parts by weight of glycerin tri 12-hydroxystearate (homologous) was dissolved in 2.5 parts by weight of chloroform. The solution was sprayed, and mixed at room temperature and 1000 rpm for 10 minutes. The blowing agent composition was prepared by treating.

Example 4

0.5 weight part of glycerin tri 12-hydroxystearate (homologous) was heated to 80 degreeC or more, and was melted. After further adding 0.5 parts by weight of Al (OH) _{2, the} mixture was stirred for 20 minutes or more to treat glycerin tri 12-hydroxystearate with Al (OH) ₂ . Subsequently, 100 parts by weight of ADCA was added to a high speed mixer, and the molten glycerin tri 12-hydroxystearate treated with Al (OH) ₂ was heated to 85 ° C. and then melted with a spray, followed by room temperature and 1000 rpm. The blowing agent composition was prepared by mixing treatment for 10 minutes at.

Example 5

A foaming agent composition was prepared by adding 100 parts by weight of OBSH and 0.5 parts by weight of glycerin tri 12-hydroxystearate (homologous) to a high speed mixer at room temperature, followed by mixing for 10 minutes at room temperature and 1000 rpm.

Example 6

A blowing agent composition was prepared according to the same methods and conditions as described in Example 4 except that 100 parts by weight of OBSH was used instead of 100 parts by weight of ADCA.

Comparative Example 1

A foaming agent sample was prepared by grinding 100 parts by weight of ADCA using a high speed mixer for 10 minutes at room temperature and 1000 rpm.

Comparative Example 2

A foaming agent sample was prepared by grinding 100 parts by weight of OBSH using a high speed mixer for 10 minutes at room temperature and 1000 rpm.

The composition of the foaming agent composition or foaming agent sample thus prepared was collectively shown in Table 2 below.

1) GTHS: glycerin tri 12-hydroxystearate

Table 3 shows various performance evaluation results with respect to the foaming agent composition or foaming agent which concerns on Examples 1-6 and Comparative Examples 1-2.

Referring to Table 3, it can be seen that the foaming agent composition of Examples 1 to 6 within the claims of the present invention can obtain a foaming agent having improved flow characteristics, load solidification characteristics, and hardening characteristics without lowering decomposition temperature. have. In addition, it can be seen that the expansion ratio of the foam is also increased. This is particularly true when metal oxides or metal hydroxides are also included. This is interpreted because the surface of the chemical foaming agent is coated with glycerin tri 12-hydroxystearate or glycerin tri 12-hydroxystearate treated with a metal oxide or a metal hydroxide to change the surface properties of the chemical foaming agent particles. .

As described above, the foaming agent composition according to the present invention has excellent foaming ratio and excellent flow characteristics, load solidification characteristics, and hardening characteristics. Therefore, the foaming composition according to the present invention is excellent in storage stability because it not only has excellent foaming performance but also minimizes solidification due to coagulation of the foaming agent particles due to product load and long time.

Claims (6)

A foaming agent composition comprising 0.05 to 10% by weight of glycerin tri 12-hydroxystearate based on the weight of the chemical foaming agent and the chemical foaming agent. The foaming agent composition of claim 1, further comprising 0.05 to 1 wt% of a metal oxide based on the weight of the chemical foaming agent. The foaming agent composition of claim 1, further comprising 0.05 to 1% by weight of metal hydroxide based on the weight of the chemical foaming agent. The foaming agent composition according to claim 2 or 3, wherein the metal element in the metal oxide or the metal hydroxide is at least one selected from the group consisting of Si, Al, Ti, and Zn. The glyceride of any one or more fatty acids selected from the group consisting of 12-hydroxystearic acid, dihydroxystearic acid, and stearic acid, based on the weight of the chemical foaming agent, characterized in that it further comprises 0.01 to 2% by weight. Foaming agent composition. The chemical foaming agent according to any one of claims 1 to 5, wherein the chemical foaming agent is azodicarbonamide, p, p-oxybisbenzenesulfonylhydrazide, dinitrosopentamethylenetetramine, p-toluenesulfonylhydrazide , Benzenesulfonylhydrazide, sodium bicarbonate, and sodium carbonate, any one or more selected from the group consisting of a blowing agent composition.