JPS5819682B2 - Coconut polyurethane foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high specific gravity polyurethane foam, and more particularly to a high specific gravity polyurethane foam that has excellent sound absorbing properties, sound insulating properties, and vibration damping properties.

Polyurethane foam has made remarkable advances in various fields in recent years, and flexible polyurethane foam takes advantage of its excellent elasticity and heat retention properties to be used as cushioning material for bedding, furniture such as sofas, chairs, automobile seats, etc. Also, rigid polyurethane foam is widely used for LPG, LPG, etc. due to its excellent insulation properties and ease of on-site construction.
It is widely used as a cold insulation material for NG, etc., and a heat insulation material for chemical plants, etc.

The specific gravity of polyurethane foams used for these purposes is usually relatively low, about 0.01 to 0.07 kg/m°.

However, such low specific gravity materials have poor sound absorbing properties, sound insulating properties, and vibration proofing properties, and are therefore unsuitable for applications such as sound absorbing materials, sound insulating materials, and vibration damping materials.

The present invention uses polyurethane foam as a sound absorbing material, a sound insulating material,
As a result of considering its use as a vibration-proofing material, it was realized that the specific gravity of the polyurethane foam could be increased.

The low foaming method and the filler addition method can be considered to increase the specific gravity of polyurethane foam, but the low foaming method has the disadvantage of high cost and is generally not used for other than special purposes, and the specific gravity is at best It is only about 1.26g/cnffi.

The specific gravity can be adjusted freely in the filler addition method, but simply adding a filler with a high specific gravity may cause the stock solution to become highly viscous, resulting in poor workability, or the urethane and filler may be mixed together. There are drawbacks such as poor affinity and resulting polyurethane foam that is extremely non-uniform and has poor physical properties.

The present inventors have conducted extensive research to solve the above-mentioned drawbacks of the filler addition method, and have found that if a high specific gravity solid powder treated with a polymeric substance having a specific hydroxyl group equivalent is used as a filler, It has been found that this drawback can be solved.

According to the present invention, the compound has at least one OH group and/or C0OH group in its molecule and has the following formula, where M is the average molecular weight of the polymeric substance, and A is one molecule of the polymeric substance. 10H group and/or -CO present in
This is the total number of OH groups.

The specific gravity treated with a polymeric substance that satisfies the relational expression shown is at least 1. A high specific gravity polyurethane foam is provided which is made by uniformly dispersing a water-insoluble solid powder of Qg/cm.

The solid powder used in the present invention is not particularly limited in type as long as it has a specific gravity of at least 1.0 g/- and is insoluble in water, and can be appropriately selected from a wide range of materials. can.

However, solid powders with too high specific gravity are difficult to uniformly disperse into polyurethane foam, so solid powders with a specific gravity of 3.59/cni or less, especially 1.5 to 3
．． A range of 0 g/- is suitable.

Examples of such solid powders include inorganic powders such as calcium carbonate, inorganic salts such as gypsum, silicic acid compounds such as silica, clay, and sand, ceramics, metal powders such as aluminum, metal oxides such as alumina and titanium dioxide, and sludge. Niblastic powder such as vinyl polymers such as vinyl chloride, polyester polymers, polyamide polymers, unsaturated polynisal polymers, epoxy resins, phenolic resins, hardened amino resins, etc.; Fibrous materials such as resin impregnation Contains fallen cotton, asbestos, metal fibers, etc.; brake lining powder, etc.

These solid powders may be used alone, or in combination of two or more.

The particle size of these solid powders is preferably fine enough not to inhibit uniform foaming of the polyurethane foam.
In general, 5 meshes or less is suitable.

The feature of the present invention is that the solid powder as described above has an OH group and/or a COOH group in the molecule and has a formula M/A.
(However, M and A have the above meanings) has a value of 35 to
150, preferably 38 to 135, before being introduced into the polyurethane foam.

When the above value exceeds 150, the solubility of the hydrophilic polymer substance in water decreases, the viscosity increases, and workability decreases.

On the other hand, if the above value is less than 30, the amount of polyisocyanate used in the urethanization reaction described below will be excessive, and the reaction heat will also be too large, resulting in non-uniform cell structure near the surface of the solid powder. It is also economically disadvantageous.

Examples of polymeric substances that can be used in the present invention include amino resins such as urea-aldehyde initial condensates and melamine-aldehyde initial condensates, polyvinyl alcohol, carboxymethylcellulose, polyoxyethylene, poly(N-methylolacrylamide), and starch. , etc.

These polymeric substances can generally be applied to the solid powder in the form of an organic solvent solution or preferably an aqueous solution.

The concentration of the polymeric substance in the solution is suitably in the range of 1 to 50% by weight or 3 to 30% by weight, and the polymeric substance is added to 1 part by weight of the solid powder at a concentration within this range. 0.1 to 3 parts by weight, preferably 0.3 to 1 part by weight
．． 5 parts by weight can be mixed and applied to the solid powder.

The polymeric substance solution can be applied to the solid powder in a conventional manner; for example, simply mixing the two is sufficient, but dipping or spraying may also be used.

The solid powder to which the polymeric substance has been applied is used as it is, or after being granulated into pellets if necessary, it is dried to a moisture content of 3% or less using a hot air dryer, a vacuum dryer, a fluidized fluid dryer, etc. Dry with.

The solid powder thus prepared is then uniformly dispersed in polyurethane foam.

Polyurethane foams can be produced by any method known per se.

The solid powder treated as described above can be blended into polyurethane foam at any stage of polyurethane foam production, for example after being mixed in advance with either or both of the polyisocyanate stock solution and the active hydrogen compound stock solution. Alternatively, the polyisocyanate stock solution and the active hydrogen compound stock solution may be mixed and then the treated solid powder may be mixed into the mixed solution.

The polyisocyanate that can be used in the production of the polyurethane foam of the present invention is an aliphatic, cycloaliphatic or aromatic organic compound having at least two isocyanate groups (NCO), and includes not only polyisocyanate monomers but also both The molecular weight is about 700 to 50, which has an incyanate group at the end.
000 prepolymer and a mixture of a polyisocyanate monomer and the prepolymer, and the polyisocyanate may be used for non-foaming to low foaming polyurethane, or for foamed polyurethane. It may be something.

Examples of such polyinsyanates include 2,4- and 2-
, 6-) lylene diisocyanate, methylene bisphenyl-4,4'-diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, m-
and P-phenylene diisocyanate, 1-chlorophenylene-2゜4-diincyanate, 1,5-naphthalene diisocyanate, polymethylene polyphenylisocyanate, dimers and trimers of these polyisocyanates, and these polyisocyanates. For example, a reaction product with a polyhydric alcohol such as trimethylolpropane having a molecular weight of i, ooo to 30,000 is included.

Active hydrogen compounds that can be used in combination with the above polyisocyanate stock solution composition include polyols, polyamines, polycarboxylic acids, etc., and specifically, ethylene glycol, propylene glycol, trimethylolpropane, glycerin, hexanetriol, etc. , pentaerythritol, ethylene diamine, diethylene triamine, and other low molecular weight active hydrogen compounds; ring-opening polymers of these low molecular weight active hydrogen compounds, polyfunctional initiators such as sorbitol, and saccharose, and cyclic ethers such as ethylene oxide and propylene oxide, that is, molecular weight is 300
Polyalkylene ether glycol of ~5,000; ethylene glycol, propylene glycol, 1,4
- Low molecular weight diols such as butadiol, 1,6-hexanediol and adipic acid, co-phosphoric acid, maleic acid, phthalic acid.

Polyester polyols obtained by dehydration polycondensation with low molecular weight dicarboxylic acids such as terephthalic acid; ring-opening polymers of cyclic esters such as caprolactone and butyrolactone; and the like.

The formation of polyurethane foam from a polyisocyanate stock solution composition and an active hydrogen compound stock solution can be carried out by various methods known per se.

For example, a polyisocyanate stock solution composition and an active hydrogen compound stock solution as described above are mixed with a blowing agent, a catalyst, a foam stabilizer, and if necessary a flame retardant, etc., and the treated solid powder described above is further added. , after stirring for a short time, it can be foamed and hardened.

As blowing agents, water, boric acid, reactive blowing agents such as nitroalkanes, and low boiling point logenated hydrocarbons are used.
As the catalyst, any catalyst for producing urethane foam can be used; for example, amine catalysts such as triethylene diamine, N-methylmorpholine, and dimethylaminoethyl ether, and tin catalysts such as stannous octoate and dimethyltin dilaurate are preferably used. be done.

As the foam stabilizer, for example, a silicone-based activator is preferable, and as the flame retardant, for example, a phosphoric acid ester type, a halogen-containing phosphoric acid ester type, or a phosphorus-containing polyether type is suitable.

Further, small amounts of other additives such as tar and pitch may be added as necessary.

Foaming can also be carried out by means known per se.
For example, any one of the one-shot method, prepolymer method, and pseudo-prepolymer method may be used, and block foaming, injection foaming, mold foaming, etc. may also be used.

The high-density polyurethane foam of the present invention not only has the inherent sound absorption properties of the polyurethane foam itself, but also has excellent vibration-proofing properties, and exhibits the unique effect of having excellent sound-insulating properties not found in ordinary polyurethane foams. .

Therefore, the polyurethane foam of the present invention is not only useful for special uses such as sound absorbing materials, vibration isolating materials, and sound insulating materials, but also can be used in a wide range of ordinary uses such as heat insulating materials, cushioning materials, backing materials, etc. Can be done.

The polyurethane foam of the present invention may be used alone for the above-mentioned purposes, or may be used as a composite with other materials such as metal plates, plywood, plastic plates, glass cloth, metal foil, asbestos, paper, etc. You can also do it.

Next, the present invention will be further explained by examples.

Example 1 Polyvinyl alcohol (average molecular weight 2420
0.0) T number 532, M/A = 45.5) After adding and kneading 100 parts of a trifunctional aqueous solution, it is molded into a plate shape and dried.

This is coarsely ground into a powder of 5 mesh or less.

On the other hand, 100 parts of polyether polyol with a molecular weight of 6000 (manufactured by Mitsui Toatsu), 0.8 parts of triethylenediamine, and 2 parts of water.
．． 5 parts, Threon 11 [manufactured by Asahi Glass ■] 6 parts, and dimethylpolysiloxane (Toshi, 5H-194) 0.
A premix of 2 parts (R liquid) and 4,4'-methylene bis diisocyanate (T liquid) are mixed in a ratio such that the NCO index is 110, and the above is added into the mixture. The crushed asbestos product described above is mixed with the mixed liquid at a weight ratio of 1:1 and foamed.

The obtained product had a semi-rigid urethane resin part with open cells, and coarsely crushed asbestos products were uniformly dispersed inside.

The specific gravity of the urethane resin part alone was 60 kg/m3, but the total specific gravity when the crushed product was included was 190 kg/m.
Example 2 100 parts of approximately 20 mesh gravel was mixed with carboxymethyl cellulose (average molecular weight: 100,000).

(C0OH number: 1111, M/A=90) Add 100 parts of a 5-coat aqueous solution, knead, form into a plate, and dry. Crush the slices to make a 10-mesh powder.

This was mixed with a urethane resin liquid prepared in the same manner as in Example 1 at a weight ratio of 1:1 and foamed.

The overall specific gravity of the foam was 400 ky/m''.

Example 3 A urea-formaldehyde initial condensate (average molecular weight 12
0. OH number 2, M/A=6 o) 30% aqueous solution 1
00 parts, knead and dry. 3 Add this to the urethane resin solution prepared in the same manner as in Example 1 at a weight ratio of 1:0.5.
Mix and foam.

The overall specific gravity of the foam was 150 kg/m3.

Example 4 Polyethylene glycol (average molecular weight 200.OH number 2°M/A=100
) Add 100 parts of the aqueous solution No. 5 and knead, then form into a plate shape and dry.

Coarsely grind this into 5 mesh pieces.

This was mixed with a urethane resin liquid prepared in the same manner as in Example 1 at a weight ratio of 1:1 and foamed.

The overall specific gravity of the foam was 1200 kg/mF.

Example 5 10 scraps of urea resin molded product crushed into about 10 mesh pieces
100 parts of a 3% aqueous solution of PoIJ (N-methylol acrylamide) (average molecular weight 600, OH number 62 M/A-100) was added to 0 parts and kneaded, then molded into a plate shape and dried.

This is coarsely ground into 15 meshes.

This was mixed with a urethane resin solution prepared in the same manner as in Example 1 except that 110 parts of tar was added to the R solution at a weight ratio of 1:1, and foamed.

The overall specific gravity of the foam was 250 kg/m3.

Reference Example The following experiment was conducted to demonstrate how excellent the high specific gravity polyurethane foam of the present invention has sound insulation properties.

A loudspeaker and a sound level meter are placed 2 m apart in a wind tunnel with a diameter of 1 m, and the volume of the loudspeaker is first adjusted so that the sound level meter indicates 90 horns.

Next, the middle between the loudspeaker and the sound level meter was blocked by a wall of polyurethane foam (manufactured from only R liquid and T liquid in Example 1) with no solid powder added and having a thickness of 100 mm and a specific gravity of 60 kg/m3. When I operated the loudspeaker at the same volume and measured the volume with a sound level meter, it was 85 horns.

In addition, the walls of the polyurethane foam were made of the high specific gravity polyurethane foam (specific gravity 1
When a similar experiment was performed with a wall of 90 kp/m3), the volume decreased to 75 horns.

Claims (1)

[Claims] 1 At least one OH group and/or COO in the molecule
H disease and F notation, where M is the average molecular weight of the hydrophilic substance, and A is the 10H group and/or -CO present in one molecule of the hydrophilic substance.
The specific gravity treated with a hydrophilic substance that satisfies the relational expression expressed by the total number of OH groups is at least 1.0 g/c
A high-density polyurethane foam having open cells made by uniformly dispersing water-insoluble solid powder of Tj3.