JPS5818925B2 - Manufacturing method of antistatic urethane foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for making antistatic urethane foams.

Due to its nature, urethane foam is a material that is easily charged with electricity, and when removing urethane foam from a mold or cutting urethane foam, the static electricity generated can cause electrostatic shock to workers, which can lead to personal injury in extreme cases. bring up

Various patents have been published regarding the prevention of such charging phenomenon of urethane foam, but most of them are of the so-called additive type.

Preventing static electricity on urethane foam using additives has the following disadvantages: (1) The additives are merely physically mixed into the foam, and they ooze out from the foam, resulting in no long-term antistatic effect.

2. If the solubility of the additive in the polyether polyol, blowing agent, foam stabilizer, etc. is poor, the foam will not have uniform antistatic properties.

3. Since additives with antistatic properties generally have a catalytic effect, foaming conditions are subject to restrictions.

The present inventors have conducted extensive research into a method for producing antistatic urethane foam that does not have these drawbacks, and have finally arrived at the present invention.

That is, in producing a urethane foam from a polyisocyanate and a polyether polyol in the presence of a blowing agent, a foam stabilizer, and a catalyst, the present invention uses a hydroxyl group having one or more tertiary nitrogen in the molecule as the polyether polyol. A quaternary product obtained by quaternizing a polyether polyol having a molecular weight of 100 to 4,000 with a quaternizing agent selected from alkyl halides, aralkyl halides, dialkyl sulfates, chlorohydrin compounds, alkyl phosphate compounds, and alkylene oxides. This is a method for producing an antistatic urethane foam characterized by using a polyether polyol.

The quaternized polyether polyol used in the present invention is obtained by adding an alkylene oxide to a compound having one or more nitrogen atoms and two or more active hydrogen atoms (hereinafter referred to as starting material) in the molecule to reduce the molecular weight per hydroxyl group. 100-40
00, and the quaternary version of this is listed.

Examples of the above starting materials include the following nitrogen compounds.

(1) Ammonia (2) Monoamine Alkylamine Alkylamine having 1 to 12 carbon atoms such as methylamine, ethylamine, propylamine: Alkanolamine such as monoethanolamine, jetanolamine, triethanolamine, monoisopropanol Amines, etc.; Aromatic amines such as ani, phosphorus, toluidine, etc.; Alicyclic amines, such as cyclohexylamine, (3) Polyamines, polyalkylene polyamines, such as ethylene diamine,
Tetra or hexamethylene diamine, sidiethylenetriamine, triethylenetetramine, etc.: Heterocyclic polyamines such as piperazine, aminoethylpiperazine, etc.;
Aromatic polyamines such as 0-lm- or P-phenylenediamine, tolylenediamine, diaminophenyl!
Among the above starting materials such as methane xylylene diamine and benzidine, alkanolamines and heterocyclic polyamines are preferred in consideration of reactivity with alkylene oxides, and particularly preferred are triethanolamine and aminoethylpiperazine. be.

Examples of alkylene oxides include ethylene oxide (referred to as EO), propylene oxide (referred to as PO), butylene oxide, styrene oxide, and epichlorohydrin.

One or more of these alkylene oxides can be used, and in that case, they may be used in any order or as a mixture.

The method for adding alkylene oxide to the starting material may be the same as conventional methods, and is usually carried out by heating to 80 to 150 DEG C. under pressure in the presence of an alkali or acid catalyst.

Among the above alkylene oxides, preferred is PO or a combination system of PO and EO.

When EO and PO are used together, the PO content of the total alkylene oxide is usually 50-100% by weight.

The amount of terminal EO is 0 to 50% by weight based on the total alkylene oxide.

The molecular weight per hydroxyl group of the polyether polyol (hereinafter referred to as tertiary nitrogen-containing polyether polyol) obtained by adding alkylene oxide to the starting material is 100.
-4000, preferably 300-3000.

If the molecular weight per hydroxyl group is less than 100, the catalytic ability of the polyether polyol is too strong, causing shrinkage of the foam;
If it is larger than 00, charging ability is lost.

The tertiary nitrogen atom-containing polyether polyol is then 4
It is quaternized by a grading agent.

Examples of quaternizing agents include alkyl halides, such as methyl chloride and methyl bromide; aralkyl halides, such as benzyl chloride and benzyl bromide; diarykyl sulfates, such as dimethyl sulfate and diethyl sulfate; chlorohydrin compounds, such as ethylene chlorohydrin, Epichlorohydrin and the like; alkyl phosphate compounds such as trimethyl phosphate can be used.

Alkylene oxide (EO) can also be used.

Among the quaternizing agents, preferred are aralkyl halides, chlorohydrin compounds, and phosphate compounds in view of quaternizing ability.

The method for quaternizing the tertiary nitrogen-containing polyether polyol may be any known method, for example, by reacting the polyether polyol with a quaternizing agent usually at 80 to 180°C.

The amount of the quaternizing agent used is 0.1 to 2 mol, preferably 0.2 to 1.2 mol, per tertiary nitrogen in the tertiary nitrogen-containing polyether polyol.

The quaternization rate of the quaternized polyether polyol obtained in this way is usually 20 to 100%, preferably 30 to 100%.
When the quaternization rate (%) is less than 20%, the antistatic effect is not sufficient.

Note that the quaternization rate can be determined by the following formula.

4th grade eyes-too(A-B)/A (%)A:
Amine value B of the tertiary nitrogen-containing polyether polyol: The amine value of the quaternized polyether polyol or the quaternary nitrogen content of the quaternized polyether polyol is usually 0.1.
4 to 4.2% by weight, preferably 0.17 to 1.4% by weight.

The quaternary nitrogen content of the quaternized polyether polyol is 0.
If it is less than 14% by weight, the antistatic effect is insufficient and 4.2
If the weight percentage is exceeded, the cream time and rise time will be longer in the reaction of the urethane foam.

That is, the average molecular weight per hydroxyl group of the quaternized polyether polyol that acts as a negative catalyst is usually 5 when producing flexible urethane foam.
00 to 4000, preferably 1000 to 3000.

When manufacturing semi-rigid urethane foam, it is usually 100~
3000, preferably 150-2000.

Further, when producing a hard urethane foam, the number is usually 30 or more, preferably 50 or more.

When producing a urethane foam using a quaternized polyether polyol, the quaternized polyether polyol can be used alone or in combination with other polyether polyols.

Other polyether polyols that can be mixed include those commonly used in the production of urethane foams, such as ethylene glycol, propylene glycol, chrycerin, trimethylolpropane, hexanetriol, pentaerythritol, diglycerin, sorbitol, and sucrose. Adding one or more alkylene oxides to a polyol.

In addition, polyether polyols having a molecular weight of 500 to 4,000 per hydroxyl group can be mentioned.

When mixing, the amount of other polyether polyols is
The amount of class nitrogen atoms is 0.1 in all polyether polyols.
4-4.2% by weight, preferably 0.17-1.4% by weight
It is set so that

The polyisocyanates used in the present invention include common polyisocyanates such as 2,4- and 2,6-tolylene diisocyanate, diphenylmethane-4,47-diincyanate, m- and p-xylylene diisocyanate, phenylene diisocyanate, biphenylene diisocyanate, 4,
47-diisocyanate, triphenylmethane-4.4
', e, -) IJ Incyanate, aromatic polyinsyanate such as polyphenylpolymethylene polyisocyanate obtained by reacting an aniline formaldehyde condensate with phosgene: ethylene diisocyanate, 1,4-tetramethylene diisocyanate, ■・6
- Aliphatic diisocyanates such as hexamethylene diisocyanate and lysine diisocyanate, and alicyclic diisocyanates such as inphorone diisocyanate and hydrogenated tolylene diisocyanate.

Among these, aromatic polyisocyanates are preferred, and tolylene diisocyanate and polyphenylpolymethylene polyisocyanate are particularly preferred, since they can be made into polyurethane foam by conventional methods.

In the present invention, auxiliary agents such as blowing agents, foam stabilizers, and catalysts are used.
be done.

The blowing agent may be a known blowing agent, such as water or a low-boiling organic fluorocarbon such as monofluorotrichloromethane or difluorodichloromethane.

Examples of foam stabilizers include silicone oil.

The catalysts may be those known for producing polyurethane foam, such as trimethylamine, dimethylbenzylamine, N-ethylmorpholine, triethylenediamine, dimethylpiperazine, 2-dimethylimidazole, dimethylaminoethanol, diethylaminoethanol, 1.
Examples include amine catalysts such as 8-diazabicyclo(5.4.0)undecene-7 and its phenol salts, triethylenediamine formate, and tin catalysts such as dibutyltin dilaurate.

In addition to the above-mentioned auxiliaries, other auxiliaries may be used if necessary.

Other such auxiliaries include dyes, pigments, plasticizers (such as dioctyl phthalate), and fillers (such as calcium carbonate).
Examples include flame retardants (such as trischloroethyl phosphate).

Furthermore, although not particularly necessary, an f4 additive (quaternary ammonium salt), which has been conventionally used to obtain an antistatic effect, may be added.

When producing urethane foam using each of the above-mentioned fine raw materials, the NCO index of the active hydrogen-containing compound containing polyincyanate and polyether polyol may be the same as in the usual case, for example, the NGO index may be 0.7 to 1.3, Preferably it is 0.9 to 1.1.

Urethane foam can be produced using known methods (for example, using polyisocyanate, polyether polyol,
A method (one-shot method) in which a composition obtained by simultaneously mixing all components such as auxiliary agents may be used, or a urethane prepolymer containing a terminal NCO group from polyincyanate polyether polyol, polyether polyol, and auxiliary agent may be used. A method of mixing, foaming, and reacting (prepolymer method) may also be used.

Among the above methods, (1) one-shot method yields a urethane foam with a low foam density.

■In the prepolymer method, the viscosity of the prepolymer is generally high, which limits the production of urethane foam.

Alternatively, it is necessary to synthesize a prepolymer.

From this point of view, the one-shot method is preferred.

The manufacturing methods for this urethane foam include molding (open mold molding, PVC integral molding method, cold cure and hot cure), slab method, on-site construction, spray coating,
It can be applied to various methods such as impregnation.

The method of manufacturing urethane foam according to the present invention is particularly useful for manufacturing soft foams such as pinerests and cushions, semi-rigid foams such as shock absorbing foams and integral skin foams, and hard foams such as insulation boards.

The integral skin foam can be produced, for example, by using the quaternized polyether polyol of the present invention as part or all of the polyol in the method described in British Patent No. 1392119, Canadian Patent No. 664192, and Japanese Patent Publication No. 47-1387. It can be carried out.

The method for producing urethane foam of the present invention is characterized in that no additives are used to provide an antistatic effect.

Therefore, the obtained urethane foam has a long-term antistatic effect and uniform antistatic ability.

Further, there is no need to particularly consider the problem of restrictions on foaming conditions due to the addition of additives.

Furthermore, the antistatic effect is equal to or better than when additives are used.

The present invention will be specifically explained below using Examples.

Parts in Examples indicate parts by weight.

Example 1 Mono-terminated polyether polyol prepared by reacting triethanolamine with PO and EO (% by weight of EO in the molecule)
=10%, 0H-V=28) 2.1 parts of benzyl chloride was added to 100 parts and reacted at 130° to 150°C for 3 hours to obtain a quaternized polyether polyol with a quaternization rate of 71%.

100 parts of this quaternized polynythyl polyol, 3.
5 parts,) 0i part of lyethylenediamine, 1.0 part of silicone foam stabilizer F-230, 0.05 part of neostane U-28
parts and 2.4- and 2.6-dolylene diisocyanate (2.4-/2.6-=80/20 weight ratio.

A urethane foam having the following properties was obtained from 41.2 parts of 5) TDI-80.

Foam density 25.9kg/ffl tensile strength
0.61 kg/crrt elongation
163% Tear strength 0.5kg/cm25%1. L
, D 4.5kg/314cr; t65%1
．． L, DI 0.7kg/314cvtSurface resistance 1.7X1013ΩReference example Terminal-graded polyether polyol (80% by weight in the molecule) made by reacting triethanolamine with PO and then EO
-10%, 0H-V=28) was used in place of the quaternized polyether polyol to obtain a urethane foam having the following properties by foaming with the same foaming recipe as described in Example 1.

It is clear that foams using quaternized polyether polyols have low surface resistance and antistatic properties.

Foam density 31.7 to 9/m3 tensile strength
1.24 kg/cm elongation 2
57% tear strength 0.95 kg7cm25%1
．． L, D I 1.0 to 9/314ca65%1
．． L, D 23 to 9/314 crrt surface resistance 1. lX1015Ω Example 2 14 parts of trimethyl phosphate was added to 100 parts of a terminally graded polyether polyol (% by weight of EO in the molecule = 10%, OH-V = 56) made by reacting aminoethylpyrazine with PO and then EO. The reaction was carried out at ~150°C for 5 hours to obtain a quaternized polyether polyol with a quaternization rate of 92%.

100 parts of this quaternized polyether polyol, 3.5 parts of water
part, triethylenediamine 0.1 part, silicone foam stabilizer F
A urethane foam having the following properties was obtained from 1.0 part of -230, 0.05 part of Neostan U-28, and 44.6 parts of TDI-80.

Foam density 24.3 kg/m' Tensile strength 0.58 kg/crA elongation
142%

Claims (1)

[Claims] 1. In producing a urethane foam from a polyisocyanate and a polyether polyol in the presence of a blowing agent, a foam stabilizer, and a catalyst, the polyether polyol contains one or more tertiary nitrogen atoms in the molecule. A quaternized polyether polyol obtained by quaternizing a polyether polyol having A method for producing antistatic urethane foam characterized by foaming. The quaternization rate of the 24-quaternized polyether polyol is 20 to 1
00% of the antistatic urethane foam according to claim 1. 3 Poly having one or more tertiary nitrogens in the molecule. The method for producing an antistatic urethane foam according to claim 1 or 2, wherein the ether polyol (polyether polyol before quaternization) has a molecular weight per hydroxyl group of 100 to 4,000. 4 Claim No. 1 in which foaming is performed by a one-shot method
A method for producing an antistatic urethane foam according to any one of items 1 to 3.