JPH11116717A - Crude cell foam and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crude cell foam most suitable for a foam used for rubbing sponges for domestic and business uses, an air cleaner for, e.g. an air conditioner, a packing material, highly air-permeable pillows and bedclothes, a hydroponic culture medium, electrical and acoustic parts, or various filters, and a process for producing it. SOLUTION: A process for producing a flexible polyurethane foam consisting of a polyol, a polyisocyanate, a foam stabilizer, a foaming agent, etc., wherein prescribed amounts of chemicals are mixed under stirring in a mixing head so as to give an almost uniform mixture, while the pressure in a mixing chamber and the amount of air blown in during mixing are controlled to respectively 1.5-2.5 kg/cm<2> and 50-1,000 cc/min so that the mixture delivered on a conveyer will be in an emulsified state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sponge eagle for home and business use, an air cleaner for an air conditioner, a packing material,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coarse cell foam which is most suitable as a foam for highly permeable pillows and bedding, a culture medium for hydroponics, electric / acoustic components, various filters, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art A flexible polyurethane foam having excellent cushioning properties and usually having a cell number of 30 to 50 cells / 25 mm is used. A flexible urethane foam having a cell number exceeding 50 cells / 25 mm is called a fine cell foam,
For example, it is used for special uses such as puffs for cosmetics.
Such a microcell foam is produced by a combination of a polyol structure, a foam stabilizer and the like. A flexible polyurethane foam having less than 30 cells is called a coarse cell foam, and is used as a functional material such as various filters, and the demand is increasing. As a method for producing this coarse cell foam, for example,
As described in Japanese Patent No. 66847, a polyether polyol having a molecular weight of 500 to 2,000 per functional group is used, a thickener is added to increase the viscosity of the polyol component system, and two kinds of polysiloxane compounds are used. A technique relating to the production of a crude cell foam by addition is disclosed.

[0003]

However, the production of a crude cell foam using such a special polyol, a thickener or a special additive as described above requires a reduction in the number of cells and a uniform cell. There is a limit to the conversion, and further, the addition of a thickener or the like increases the workability and the possibility of increasing the cost. In recent years, there has been an increasing demand for foams having a cell number of 15 cells / 25 mm or less for use in mats and air filters of fish and shellfish.

[0004]

In order to solve these problems, the present inventor has proposed that a conventional urethane foam having a normal compounding formulation can be used for 6 to 6 times without substantially changing the current workability.
In order to obtain a coarse cell foam of 15 pieces / 25 mm, the present invention is completed by adjusting the internal pressure of the mixing chamber and the air injection amount and changing the discharge state of the mixed liquid to produce a coarse cell foam. Reached.

The present invention provides a flexible polyurethane foam comprising a polyol, a polyisocyanate, a foam stabilizer, a foaming agent and the like, wherein the number of cells is 6 to 15 cells / 25 mm. is there. Further, the present invention relates to a method for producing a flexible polyurethane foam comprising a polyol, a polyisocyanate, a foam stabilizer, a foaming agent, etc., wherein a predetermined amount of a drug is stirred and mixed in a mixing head so as to be substantially uniform. Pressure of the mixing chamber at the time of 1.5 to 2.5 kg / cm
² , the air injection rate is 50-1000cc / min,
An object of the present invention is to provide a method for producing a coarse cell foam, wherein a discharged mixed liquid is in an emulsified state.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The formulation of the flexible urethane foam used in the present invention may be a commonly used formulation,
Further, a filler, a coloring agent, an antibacterial agent, an antistatic agent, a flame retardant and the like can be added according to the performance required for the coarse cell foam.

Accordingly, the polyol is not particularly limited to ether-based and ester-based polyols. For example, alkyl oxide addition of polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, and sucrose is not required. Products, diethanolamine, triethanolamine, alkyl oxide adducts such as ethylenediamine, styrene,
Polyether polyols such as graft-type polymer polyols such as acrylonitrile, malonic acid, succinic acid,
Aliphatic carboxylic acids such as adipic acid or phthalic acid,
Polyester polyol having a hydroxyl group at a terminal obtained by polymerizing an aromatic carboxylic acid such as terephthalic acid or a mixture thereof with an aliphatic glycol such as ethylene glycol, propylene glycol or diethylene glycol or a triol such as trimethylchlorpropane or glycerin. Alternatively, polyester polyols such as polycaprolactone obtained by ring-opening polymerization of lactone can be used. Preferably, the hydroxyl value of each polyol is 20 to 160 mgKOH / g, more preferably 25 to 80 mgKOH / g. One or a mixture of two or more polyols is used.

The polyisocyanate is not particularly limited, and tolylene diisocyanate, diphenylmethane diisocyanate, triphenyl diisocyanate, paraphenylene diisocyanate, xylene diisocyanate and the like can be used. An 80:20 to 65:35 mixture of isocyanate and 2,6-tolylene diisocyanate is used.

Further, as the catalyst, those generally used for producing flexible polyurethane foams can be used.
For example, there are an organotin compound catalyst and an amine catalyst. Examples of the organotin compound catalyst include stannas octoate, stannas oleate, dibutyltin dilaurate, dibutyltin di-2-ethylhexoate, and dibutyltin diacetate. As the amine catalyst, triethylamine, triethylenediamine, N-ethylmorpholine, N
-Methylmorpholine, tetramethylpropylenediamine, tetramethylhexamethylenediamine, tetramethylethylenediamine, dimethylethanolamine and the like.

In the present invention, as the blowing agent, water is mainly used as a blowing agent, but if necessary, low boiling halogenated hydrocarbons such as methylene chloride, trichloromonochloromethane, dichlorodifluoromethane and trichloroethane are also used. be able to.

As a foam stabilizer, an organic silicon-based surfactant is used. For example, L-52 manufactured by Nippon Unicar Co., Ltd.
0, L-532, L-540, L-544, L-355
0, L-5740S, L-5740M, L-6202
SH-190, SH-19 manufactured by Toray Silicone Co., Ltd.
2, SH-194, SRX-294, SRX298, etc.
Shin-Etsu Silicone F-114, F-121, F-1
22, F-230, F-258, F-260B, F-3
17, F-341, F-601, F-606 and the like can be used.

The above-mentioned polyols, polyisocyanates, catalysts, foaming agents, foam stabilizers and other additives are simultaneously and uniformly mixed in a mixing head in a predetermined amount suitable for the required density of the coarse cell foam. Stir and mix. At this time, the internal pressure of the mixing head chamber is set to 1.5 to 2.
Adjusted to 5 kg / cm ^2, the air injection amount 50 to 1000
cc / min. When mixing head pressure in the chamber is less than 1.5 kg / cm ^2, the shape of the cell becomes finer, not preferred, and in order but the cell becomes rough exceeds 2.5 kg / cm ² become unstable formulation , It is difficult to obtain a good foam. If the air injection amount at that time is less than 50 cc / min, the cell becomes coarse, but the prescription becomes unstable, and 1000 cc / m
When the value exceeds “in”, the cells gradually become finer, and furthermore, the cells become rough like the state of excessive stirring.

Next, the mixed liquid is poured in an emulsified state on a conveyor covered with kraft paper or the like, and the reaction is promoted to form the crude cell foam of the present invention. This coarse cell foam can have a cell number of 6 to 15 cells / 25 mm. When the obtained foam is used for a mat or a filter of fish and shellfish, it is possible to form a membrane by a usual method. Includes

[0014]

The coarse cell foam of the present invention has a cell number of 6-15.
Since it is 25 pieces / piece, it can be optimally used as a filter or a sponge swab. In addition, the production method of the present invention does not require a special compounding recipe,
The work efficiency is good and there is no change in cost.
Furthermore, since a uniform cell can be formed, it is possible to manufacture a coarse cell foam having a high product value.

[0015]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. Example In order to obtain a coarse cell foam having a density of about 25 kg / m ³ , the following formulation was carried out. Polyol ¹⁾ 100 parts by weight Water 3.6 parts by weight Triethylenediamine 0.05 parts by weight Silicone foam stabilizer ²⁾ 0.8 parts by weight Stanas octoate 0.3 parts by weight TDI 52 parts by weight 1) Propylene oxide to glycerin A polyether polyol having a hydroxyl value of 56 mgKOH / g obtained by addition polymerization. 2) L-540 manufactured by Nippon Unicar Co., Ltd. The foaming was performed by adjusting the internal pressure of the chamber and the amount of air with the above composition. Table 1 shows the properties of the obtained foam and the evaluation results of the number of cells.

[0016]

In Comparative Example 1, the air amount was set to 0 cc /
Because of the min, the cells were coarsened, but became independent cells, and the foam was cracked. In Comparative Example 2, the air amount was 100
Since it exceeded 0 cc / min, the cells became fine, and the desired number of cells was not obtained. Further, in Comparative Example 3, since the internal pressure of the chamber was less than 1.5 kg / cm ² , the state of the cells flowing into the conveyor became liquid, and the cells became fine and did not reach the desired number of cells. Furthermore, in Comparative Example 4, since the chamber internal pressure exceeded 2.5 kg / cm ² , the cells were crushed. In Examples 1 to 4 of the present invention, a desired urethane foam having 6 to 15 cells / 25 mm could be obtained.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akira Kurita 224 Asanuma-cho, Sano City, Tochigi Prefecture

Claims (3)

[Claims] 1. A flexible polyurethane foam comprising a polyol, a polyisocyanate, a foam stabilizer, a foaming agent and the like, wherein the number of cells is 6 to 15 cells / 25 mm. 2. A method for producing a flexible polyurethane foam comprising a polyol, a polyisocyanate, a foam stabilizer, a foaming agent, and the like, wherein a predetermined amount of a drug is stirred and mixed in a mixing head so as to be substantially uniform. Of the mixing chamber at 1.5 to 2.5 kg / cm
² , the air injection rate is 50-1000cc / min,
A method for producing a coarse cell foam, wherein a mixed liquid discharged onto a conveyor is emulsified. 3. The cell number of the coarse cell foam is 6 to 15 cells /
3. The method for producing a coarse cell foam according to claim 2, wherein the thickness is 25 mm.