JPH0687943A - Production of rigid expanded synthetic resin - Google Patents

Abstract

PURPOSE:To obtain a rigid expanded synthetic resin by using a specific polyol. CONSTITUTION:Firstly, a polyether polyol with a hydroxyl value of 300-500 is prepared by reaction of an 1-(2-aminoethyl)piperazine-3 mole PO-added product with PO and/or EO using a KOH catalyst. Then, this polyol is made to react with a crude MDI in the presence of a foaming agent such as water or R11 to obtain the objective rigid polyurethane foam, which is excellent in adhesiveness to base materials or facing materials.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a rigid foam synthetic resin such as a rigid polyurethane foam.

[0002]

2. Description of the Related Art It is widely known that a rigid foam synthetic resin is produced by reacting an active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group with a polyisocyanate compound in the presence of a foaming agent. It is being appreciated.

Examples of active hydrogen compounds include polyhydroxy compounds and polyamine compounds. Examples of the rigid foam synthetic resin obtained include rigid polyurethane foam and rigid polyisocyanurate foam.

As the foaming agent, R11 which is a specific CFC
(Trichloromonofluoromethane), and optionally R12 (dichlorodifluoromethane) are also commonly used with water. However, there is a concern that these specific CFCs may destroy the ozone layer in the stratosphere and affect biological systems,
Recently, its production and use are being restricted.

Also in the field of urethane foaming, R11 and R1
It is required to drastically reduce the amount of use of item 2 or abolish it. At this time, a method is adopted in which R11 and R12 are reduced by increasing the amount of water, which produces carbon dioxide gas by the reaction with the polyisocyanate compound, as a blowing agent component.

However, as the amount of water increases, the number of urea bonds increases, which makes the foam brittle. When it is adhered to a base material or face material, the adhesiveness is remarkably reduced, and the foam easily peels off. When the foam is used as a spray foam, the foam shrinks violently in the temperature range, and immediately after spraying, the foam rises due to a phenomenon called lateral expansion, which causes problems such as impractical use.

As a method for improving the adhesiveness, it is conceivable to add a high molecular weight polyol or a low hydroxyl value polyol having a small number of functional groups, which is generally used in the production of flexible polyurethane foam. There arises a problem that the foam formed tends to shrink.

[0008]

DISCLOSURE OF THE INVENTION The present invention is directed to the production of rigid foaming synthetic resins such as rigid polyurethane foam, in the case of significantly reducing specific CFCs such as R11 used as a foaming agent to increase the amount of water, and to substitute foaming of R11. Problems that occur when HCFC, HFC, etc. are used together with water as an agent, that is, the adhesiveness to the base material and face material becomes extremely poor, the lateral spread becomes remarkable, and the construction and production become impossible. It is an object of the present invention to solve problems such as severe shrinkage of foam in a temperature range and extremely brittle foam to be obtained.

[0009]

The present invention has been made to solve the above-mentioned problems. That is, in a method for producing a rigid foam synthetic resin by reacting an active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group with a polyisocyanate compound in the presence of a foaming agent, at least one active hydrogen compound is used. Part is a piperazine-based polyether polyol obtained by addition reaction of alkylene oxide to piperazine and / or 1- (2-aminoethyl) piperazine.

The piperazine and 1- (2-aminoethyl) piperazine in the present invention have the structures shown in Chemical formula 1 and Chemical formula 2, respectively.

[0011]

[Chemical 1]

[0012]

[Chemical 2]

In the present invention, piperazine and / or 1-
The alkylene oxide added to (2-aminoethyl) piperazine is preferably an alkylene oxide having 2 to 4 carbon atoms. Specifically, at least one selected from ethylene oxide, propylene oxide, 1,2-butylene oxide and 2,3-butylene oxide is preferable. Particularly, propylene oxide alone or a combination of propylene oxide and ethylene oxide is preferable.

The hydroxyl value of the piperazine-based polyether polyol in the present invention is not particularly limited, but it is preferably 100 to 800 mgKOH / g, particularly preferably 250 to 650 mgKOH / g, and further 30.
Most preferably, it is 0 to 600 mgKOH / g.

The present invention is a method for producing a rigid foamed synthetic resin by using the above-mentioned piperazine-based polyether polyol or the other active hydrogen compound. Other active hydrogen compounds include polyhydric alcohols, polyether polyols, polyester polyols, and compounds containing primary and secondary amino groups.

As the polyhydric alcohol, ethylene glycol, diethylene glycol, propylene glycol,
Glycerin, diglycerin, 1,4-butanediol,
1,6-hexanediol, trimethylolpropane,
There is pentaerythritol and the like.

Examples of polyether polyols include
The polyether polol obtained by adding the alkylene oxide or caprolactone to an initiator such as a polyhydric alcohol, a saccharide or an alkanolamine can be mentioned. A polyether polyol obtained by adding propylene oxide or ethylene oxide is particularly preferable. It is also possible to use a polyol composition in which fine particles of vinyl polymer are dispersed in a polyether-based polyol, which is called a polymer polyol or a graft polyol.

Examples of the polyester polyols include polyhydric alcohol / polycarboxylic acid condensation type polyols and cyclic ester ring-opening polymer type polyols. As the primary or secondary amino group-containing compound, ethylenediamine,
Examples include propylenediamine, dioctylamine, the above-mentioned polyhydric alcohols, and compounds obtained by aminating the ends of polyether polyols.

The hydroxyl value of the polyol combined with these piperazine-based polyether polyols is not particularly limited, but usually, the hydroxyl value is 100 to 800 mg.
KOH / g polyol is used.

The piperazine-based polyether polyol is preferably used in an amount of 20 to 100% by weight based on the total active hydrogen compounds. Particularly, 40 to 100% by weight is preferable.

The hard foam synthetic resin of the present invention is obtained by reacting the above-mentioned active hydrogen compound and polyisocyanate compound as basic raw materials. Generally, it is necessary to use various additives other than this basic raw material. Usually essential additives are a foaming agent, a foam stabilizer, and a catalyst. Further optionally used additives include, for example, flame retardants, fillers,
There are stabilizers, viscosity reducers, colorants and the like. These additives are usually added to the polyol, but may be added to the polyisocyanate compound as needed.

The present invention preferably uses water as the blowing agent. The amount used is 0.
2 to 10% by weight is preferable. Especially 1.0 to 8.0% by weight
Preference is given to using. Further, although the technique of the present invention can be used for a formulation in which water is used as a sole foaming agent, it is preferable to use a low boiling point halogenated hydrocarbon together as a foaming agent.

As the low-boiling halogenated hydrocarbon, R1
1, R12, monochlorodifluoromethane (R22),
1,1,2-trichloro-1,2,2-trifluoroethane (R11
3), 1,2-dichloro-1,1,2,2-tetrafluoroethane (R114), monochloropentafluoroethane (R1
15), 2,2-dichloro-1,1,1-trifluoroethane (R
123), 1,2-dichloro-1,1,2-trifluoroethane (R123a), 1,1-dichloro-1-fluoroethane (R
141b), 1-chloro-1,1-difluoroethane (R14
2b), 3,3-dichloro-1,1,1,2,2-pentafluoropropane (R225ca), 1,3-dichloro-1,1,2,2,3-pentafluoropropane (R225cb), 3 -Chloro-1,1,
2,2-Tetrafluoropropane (R244ca), 1-Chloro-1,2,2,3-tetrafluoropropane (R244c
b), 3-chloro-1,1,2,2,3-pentafluoropropane (R235ca), 1,1-dichloro-1,2,2-trifluoropropane (R243cc), 1,1,1,2 -Tetrafluoroethane (R134a), 1,1,1,2,3,3-hexafluoropropane (R236ea), difluoromethane (R32),
There are fluorine-containing halogenated hydrocarbons such as hexafluorobutane (R356) and dodecafluoropentane.

In addition, halogenated hydrocarbons containing no fluorine atom such as methylene chloride, fluorine-containing halogenated hydrocarbons other than the above, low boiling point hydrocarbons such as butane, hexane and isopentane, inert gases such as air and nitrogen I have gas. Of course, these foaming agents are used alone,
It is also possible to use them in combination.

Organopolysiloxane as a foam stabilizer
Nonionic surfactants such as polyoxyalkylene copolymers and silicone-glycol copolymers are exemplified. As the catalyst, a commonly used amine catalyst or metal catalyst can be used. Specifically, amino group-containing compounds such as triethanolamine, tetramethylhexamethylenediamine, triethylenediamine, bis- (2-dimethylaminoethyl) ether, dibutyltin dilaurate, lead octylate, lead naphthenate and other organic metals. The compounds are used alone or in combination.

The flame retardant is not particularly limited, but Tris (2
A halogen-containing phosphate compound such as -chloroethyl) phosphate, tris (2-chloropropyl) phosphate, and tris (dichloropropyl) phosphate is often used.

In urethane foaming, a method of mixing two components having an active hydrogen compound as one component and a polyisocyanate compound as another component is usually adopted. But,
Divide at least one component into two or more components,
It is also possible to mix three or more components in total. Further, the active hydrogen compound and the polyisocyanate compound can be reacted by a prepolymer method or a pseudo prepolymer method,
Usually, the one-shot method is used for the reaction.

The polyisocyanate compound in the present invention can be appropriately used from those generally used in the past. Typical examples are aromatic, alicyclic, or aliphatic polyisocyanates having two or more isocyanate groups, modified polyisocyanates obtained by modifying them, and mixtures of two or more thereof. .

Specifically, for example, tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate (commonly called crude MD
I), polyisocyanates such as xylylene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate, and their prepolymer type modified products, nurate modified products, and urea modified products. Crude MDI is particularly preferable. The amount used is 0.6 to 3.0 equivalents, particularly 0.8 to 2.0, based on the hydroxyl equivalents of all active hydrogen compounds.
Equivalent weights are preferred.

The present invention is also useful in the production of rigid polyurethane foams, urethane-modified polyisocyanurate foams and other rigid foams which require adhesive strength. In particular, the hard foam synthetic resin of the present invention is most suitable for spray foam, continuous production laminated board foam, continuous production sizing foam, or heat insulation panel foam produced by injection molding due to its adhesive strength.

[0031]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[Production of Polyol] Polyol A: 1- (2-aminoethyl) piperazine-
A polyether polyol having a hydroxyl value of 500 mgKOH / g obtained by further reacting propylene oxide with a 3 mol propylene oxide adduct using a KOH catalyst. Polyol B: hydroxyl value 450 obtained in the same manner as A
mg KOH / g polyether polyol. Polyol C: 1- (2-aminoethyl) piperazine-
A polyether polyol having a hydroxyl value of 450 mgKOH / g, which is obtained by further reacting propylene oxide and ethylene oxide with a 3 mol propylene oxide adduct using a KOH catalyst. Polyol D: Hydroxyl value 300 obtained in the same manner as A
mg KOH / g polyether polyol. Polyol K: Polyether polyol having a hydroxyl value of 450 mgKOH / g, obtained by further reacting piperazine-2 mol propylene oxide adduct with propylene oxide using a KOH catalyst.

Polyol E: Hydroxyl value 480 obtained by reacting triethanolamine with propylene oxide
mg KOH / g polyether polyol. Polyol F: hydroxyl value 4 obtained by reacting ethylenediamine with propylene oxide and ethylene oxide
50 mg KOH / g polyether polyol. Polyol G: A polyether polyol having a hydroxyl value of 350 mgKOH / g obtained by reacting sucrose with propylene oxide. Hydroxyl value 300 obtained in the same manner as Polyol H: G
mg KOH / g polyether polyol. Polyol I: A polyether polyol having a hydroxyl value of 250 mgKOH / g obtained by reacting ethylenediamine with propylene oxide. Hydroxyl value 750 obtained in the same manner as Polyol J: I
mg KOH / g polyether polyol.

First, 100 parts by weight of a total of polyols of the types and proportions shown in the table were weighed in a 500 cm ³ plastic cup, 1.5 parts by weight of a silicone foam stabilizer (L-5421, manufactured by Nippon Unicar Co., Ltd.), and as a catalyst, Triethylenediamine solution (DABCO33LV, manufactured by Air Products and Chemicals) was used as a flame retardant, the necessary amount for gel time of about 25 seconds, and tris (2-chloropropyl).
10 parts by weight of phosphate (TMCPP, manufactured by Daihachi Chemical Co., Ltd.), water of parts by weight shown in the table, and a foaming agent of the type and parts shown in the table are added and thoroughly mixed and stirred by a disk-type stirrer. The liquid temperature was adjusted to 20 ° C.

Next, in this polyol-side stock solution, crude diphenylmethane diisocyanate (Millionate MR-100, manufactured by Nippon Polyurethane Industry Co., Ltd., NCO: 31.0%) whose liquid temperature was previously set to 20 ° C. is shown in the table.
X (INDEX) is added by weight as shown in the table,
High-speed stirring was performed at room temperature of 20 ° C. for 5 seconds, and foaming was performed in a 20 cm cubic wooden box having an open top. At this time, an iron piece (width: 2.5 cm, length: 7.5 cm, thickness: 0.05 cm) that had been installed in the wooden box in advance was peeled off after the foam was cured, and the maximum strength at that time was taken as the adhesive strength. .

Type and composition of raw materials (all used parts are parts by weight), and core density of the obtained foam (unit: kg /
m ³ ), the evaluation of the adhesion of the foam to the iron piece is shown in the table. In Example 18, a quaternary ammonium salt (DABCO-TMR, manufactured by Air Products and Chemicals) known as a trimerization catalyst was used instead of the triethylenediamine solution (DABCO33LV).

In the table, the adhesion to the iron piece was judged based on the following. A: Adhesive strength improved by 50% or more as compared with Comparative Example 1. Good: The adhesive strength was improved to be equal to or less than 50% as compared with Comparative Example 1. B: Less than 30% decrease in adhesive strength as compared with Comparative Example 1. X: A reduction in adhesive strength of 30% or more as compared with Comparative Example 1.

The foaming agents used are as follows. Foaming agent a: R11 Foaming agent b: R11, methylene chloride, isopentane mixture (XR-8410F manufactured by Asahi Glass Co., Ltd.) Foaming agent c: R141b Foaming agent d: R12 Foaming agent e: R22

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

Next, lead octylate (nickel octix lead 20%, was added to the polyol-side stock solutions of Examples 1 to 12).
(Manufactured by Nippon Kagaku Sangyo Co., Ltd.), and the rise time during the foaming reaction at a liquid temperature of 10 ° C. was adjusted to about 15 seconds, and then the polyol side stock solution and the crude diphenylmethane diisocyanate (crude MDI) were mixed with a gasmer. Using a foaming machine manufactured by the company, when spray-foaming each of the base materials of concrete, gypsum board, and plywood at a liquid temperature of 45 ° C. and an air temperature of 5 ° C., it showed a good spray state, and the obtained rigid polyurethane foam was The adhesive strength was practically no problem with the substrate.

[0043]

EFFECT OF THE INVENTION By using a piperazine-based polyether polyol in the present invention, the amount of water used as a foaming agent is increased to greatly reduce or completely eliminate specific freons such as R11 and R12. Can be manufactured. The polyurethane foam of the present invention has excellent adhesiveness to a substrate or face material and is suitable for boards. The polyurethane foams of the invention are also suitable for spray foams.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI technical display location C08G 101: 00) C08L 75:04 (72) Inventor Hiromitsu Odaka 2-15 Shimorenjaku, Mitaka City, Tokyo Ten

Claims (3)

[Claims] 1. A method for producing a rigid foamed synthetic resin by reacting an active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group with a polyisocyanate compound in the presence of a foaming agent, comprising: Is a piperazine-based polyether polyol obtained by addition reaction of piperazine and / or 1- (2-aminoethyl) piperazine with an alkylene oxide. 2. The method according to claim 1, wherein the hydroxyl value of the piperazine-based polyether polyol is 100 to 800 mgKOH / g. 3. The method according to claim 1, wherein water is used as a foaming agent in an amount of 0.2% by weight or more based on all active hydrogen compounds.