JP2003147040A - Method for producing expanded synthetic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a good-quality expanded synthetic resin by using a simple expansion apparatus without using any chlorofluoro(hydro)carbon as a foaming agent. SOLUTION: This expanded synthetic resin is produced by reaction between an active hydrogen compound and a isocyanate compound by the use of a foaming agent comprising 1,1,1,3,3-pentafluoropropane(HFC-245fa) and 1,1,1,2- tetrafluoroethane(HFC-134a).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a foamed synthetic resin such as polyurethane foam, and more particularly to a method for producing a foamed synthetic resin using a simple foaming device and a specific foaming agent.

[0002]

2. Description of the Related Art Conventionally, there has been known a manufacturing method using a simplified foaming apparatus whose outline is shown in FIG. 1 for manufacturing a foamed synthetic resin such as polyurethane foam. This foaming device operates only by operating the pressure of a gas such as nitrogen supplied from a gas cylinder, and discharges and mixes the active hydrogen compound component and the isocyanate compound component from two cylinders filled separately. The discharge amount is controlled by the flow controller. Further, the active hydrogen compound component and the isocyanate component are uniformly mixed by the static mixer provided at the discharge port. Further, for the purpose of improving the mixing property, dichlorodifluoromethane (boiling point: -30 ° C) (hereinafter, C
It is general to partially use a foaming agent having a boiling point lower than room temperature, such as FC-12).

An example of such a simple foaming device is Auto Floss (manufactured by Asahi Glass Co., Ltd.). This is (1) easier to reduce the injection amount because it has better fluidity than conventional low-pressure foaming machines and high-pressure foaming machines, and (2) large because the foaming pressure is low. It does not require mold clamping equipment. (3) As a result, it has the features of reducing equipment investment.

[0004]

Trichlorofluoromethane (CFC-11) which has been widely used as a blowing agent.
Chlorinated fluorinated carbon (hereinafter referred to as CFC), which is extremely stable in the atmosphere, such as CFC-12 and CFC-12, reaches the stratosphere above the atmospheric layer without being decomposed, and is decomposed by the action of ultraviolet rays, etc. There is a danger of destroying the ozone layer.

On the other hand, 1,1-dichloro-2,2,2-trifluoroethane (which is considered to be less dangerous because it has a hydrogen atom in its molecule and decomposes before reaching the ozone layer in the atmosphere) Hereinafter referred to as HCFC-123), 1,1
-Dichloro-1-fluoroethane (hereinafter referred to as HCFC-1
41b), chlorodifluoromethane (hereinafter referred to as HC
Chlorinated fluorinated hydrocarbons such as FC-22 (hereinafter referred to as HCFC) have been proposed as a foaming agent and have been widely used. However, these substances also have an ozone depletion potential even though they are small, and cannot be an essential solution.

Therefore, such CFC and HCFC
In place of the above, it is desired to develop a foaming agent that does not cause ozone layer depletion and a synthetic resin manufacturing technology for foaming.
As an alternative blowing agent for C, fluorinated hydrocarbon (hereinafter referred to as HF
It has been proposed to use C). HFC includes 1,1,1,3,3-pentafluoropropane (hereinafter, referred to as HFC-245fa), 1,1,1,2-tetrafluoroethane (hereinafter, referred to as HFC-134a), 1,1,1. , 3,3-pentafluorobutane,
1,1,1,3,3-pentafluorobutane (hereinafter H
FC-365mfc) and the like.

Generally, in froth foaming in which a low-boiling foaming agent is also used, the occurrence of voids due to the presence of the low-boiling foaming agent is a problem. In this regard, US Pat. No. 5,514,724 states that it is desirable to use a foaming agent having a boiling point of 300 K or less as a foaming agent.
2,2-Pentafluoropropane (HFC-245c
b, boiling point: -18.3 ° C), 1,1,2,3,3-pentafluoropropane (HFC-245ea, boiling point: 3
9.3 ° C) and (HFC-365mfc, boiling point: 40
℃) and the like. Since HFC-245cb has a low boiling point, froth voids are likely to occur, and the appearance of the resulting foam is likely to be poor.
45ea and 365mfc have a problem that the dimensional stability of the obtained foam is not good.

That is, it is desired to develop a method for producing a foamed synthetic resin having a good appearance by using a simple foaming device without fear of destroying the ozone layer.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an active hydrogen compound is produced by using a simple foaming device that operates only by operating the pressure of a gas supplied from a gas cylinder. A method for producing a foam synthetic resin, comprising reacting an isocyanate compound with an isocyanate compound in the presence of a catalyst and a foaming agent, wherein the foaming agent comprises 1,1,1,3,3-
Pentafluoropropane (HFC-245fa) and 1,
1,1,2-Tetrafluoroethane (HFC-134
There is provided a method for producing a foamed synthetic resin, which comprises using a fluorinated hydrocarbon containing a). By using these foaming agents in combination, a good foaming synthetic resin having uniform cells can be obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, H containing HFC-245fa and HFC-134a as a foaming agent.
FC is used. When HFC-245fa is used alone, it is difficult to obtain a foam having a uniform cell size, and a part of the cell may be destroyed by an external factor before the cell is formed in the initial stage of the foaming reaction. Not preferable. Also,
When HFC-134a is used alone, so-called froth voids are likely to occur, and the surface appearance tends to be poor, which is not preferable. In any case, particularly when molding a large-sized molded product, defects such as thermal conductivity, surface appearance, and dimensional stability due to these molding defects are likely to occur. HFC-2
The mixing ratio of 45fa and HFC-134a is 2 by mass ratio.
0 to 99/1 to 80 are preferable, and 40 to 99/1 to 60
Is more preferable.

In the present invention, other foaming agents can be used together, and water is particularly preferably used together. Examples of the foaming agent other than water that can be used in combination include HFC-245.
HFCs other than fa and HFC-134a, low boiling point fluorinated carbons, low boiling point hydrocarbons, inert gases and the like can be mentioned. In the present invention, the low boiling HFC, the low boiling fluorinated carbon, and the low boiling hydrocarbon each have a boiling point of 1 or less.
It is preferably lower than 00 ° C, more preferably 50 ° C or lower. HFC in all blowing agents except water
-The total ratio of HFCs other than 245fa and HFC-134a and fluorinated carbon is preferably 20% by mass or less,
It is more preferably 10% by mass or less.

In addition, HF in all blowing agents except water
The total ratio of C-245fa and HFC-134a is 5
0 mass% or more is preferable, and 85 mass% or more is more preferable. Examples of HFCs that can be used in combination include those described below, and of these, HFC-365mfc is most preferable. H
When using FC-365mfc, the amount used is HF
The total amount of C-245fa and HFC-134a is 100 parts by mass, preferably 15 parts by mass or less, more preferably 10 parts by mass or less. The usage of each of the three parties is HFC-245fa / HFC-134a / HFC-
The mass ratio of 365 mfc is 40-80 / 19-5.
It is preferably 0/1 to 15.

The amount of the specific foaming agent used in the present invention is
HFC-245f per 100 parts by mass of active hydrogen compound
The total amount of a and HFC-134a is preferably 5 to 150 parts by mass, more preferably 20 to 60 parts by mass. Further, it is preferable to use water in combination as a foaming agent, and the amount thereof is preferably 0.1 to 5 parts by mass, and more preferably 2 to 3 parts by mass with respect to 100 parts by mass of the active hydrogen compound.

Other than the above, HFCs and fluorinated carbons that can be used in combination
Include the following compounds: CH_TwoF_Two, CF_Two
HCH_Three, CF_ThreeCF_TwoH, CF_ThreeCH_Three, CF_ThreeCF
_TwoCF_TwoH, CF_ThreeCFHCF_Three, CHF_TwoCF_TwoCH
F_Two, CF_ThreeCF_TwoCFH_Two, CF_ThreeCHFCHF_Two,
CF_ThreeCH_TwoCF_Three, CF_TwoHCF_TwoCFH_Two, CF _Three
CF_TwoCH_Three, CF_TwoHCHFCF_TwoH, CF_ThreeCHF
CFH_Two, CFH_TwoCF_TwoCFH_Two, CF_TwoHCF_TwoC
H_Three, CF_TwoHCHFCFH_Two, CF_ThreeCHFCH_Three,
CF_TwoHCH_TwoCF_TwoH, CF_ThreeCH_TwoCFH_Two, CF
H_TwoCF_TwoCH _Three, CH_TwoFCHFCH_TwoF, CF_TwoH
CHFCH_Three, CH_TwoFCH_TwoCF_TwoH, CF_ThreeCH_Two
CH_Three, CH_ThreeCF_TwoCH_Three, CH_TwoFCHFCH_Three,
CH_TwoFCH_TwoCH_TwoF, CHF_TwoCH_TwoCH_Three, CH
_ThreeCHFCH_Three, CH_TwoFCH_TwoCH_Three, CF_ThreeCF_Two
CF_TwoCH_Three, CF_ThreeCH_TwoCH_TwoCF_Three, CF_ThreeCH
FCF_TwoCH_Three, CF_ThreeCHFCHFCF_Three, CF_ThreeC
F_TwoCF_TwoCH_TwoF, CF _ThreeCHFCH_TwoCF_Three, CH
_ThreeCF_TwoCF_TwoCHF_Two, CF_ThreeCF_TwoCHFCH
F_Two, CF_ThreeCF_TwoCH_TwoCHF_Two, CF_ThreeCHFCH
FCH_Three, CF_ThreeCH (CF_Three) CH_Three, CH_ThreeCF
(CF_Three) CHF_Two, CH_ThreeCH (CF_Three) CH_TwoF,
CH_ThreeCH (CF_Three) CHF_Two, CH_TwoFCF (C
F_Three) CH_TwoF, CH_ThreeCF (CHF_Two) CHF_Two, C
F_Four, C_TwoF₆, C_ThreeF₈, C_FourF₁₀, C₅F ₁₂,
C₆F₁₄, C₇F₁₆, C₅F₁₀(Perfluoro
Clopentane), C₆F₁₂(Perfluorocyclohex
Sun), C₆F₆(Perfluorobenzene).

Examples of the hydrocarbon include propane, butane, pentane, cyclopentane, hexane and various isomers thereof. Examples of the inert gas include air, nitrogen and carbon dioxide gas.

Examples of the active hydrogen compound used in the present invention include polyols, polyphenols and polyamines. Examples of the polyol include polyether polyols, polyester polyols, polyhydric alcohols, hydroxyl group-containing diene polymers, and the like. However, as the polyol, a polymer-dispersed polyol in which polymer particles are stably dispersed in the compound may be used. In the present invention, among these active hydrogen compounds, it is preferable to use the polyether polyol alone or to use the polyether polyol and another active hydrogen compound in combination.

The polyether polyol can be obtained by ring-opening addition polymerization of a cyclic ether as an initiator in the presence of a catalyst. As the initiator, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, tripropylene glycol, glycerin,
Examples include polyhydric alcohols such as trimethylolpropane, pentaerythritol, diethanolamine, and triethanolamine; sugars; alkanolamines, and small amounts of these cyclic ether adducts. Examples of the cyclic ether include alkylene oxides such as propylene oxide, butylene oxide and ethylene oxide.
Of these, propylene oxide alone or a combination of propylene oxide and ethylene oxide is preferable.

Examples of the polyester polyols include polyhydric alcohols / polyhydric carboxylic acids condensation type polyols and cyclic ester ring-opening polymerization type polyols. Examples of the polyhydric alcohols include the polyhydric alcohols used as the initiator.

The polyphenol is a compound having two or more phenolic hydroxyl groups, and is a resol-type initial condensate obtained by condensation-bonding phenols with excess formaldehyde in the presence of an alkali catalyst. There are a benzylic type initial condensate reacted in a non-aqueous system when synthesizing a product, and a novolak type initial condensate obtained by reacting excess phenols with formaldehyde in the presence of an acid catalyst. The molecular weight of these precondensates is 200
It is preferably about 10,000 to 10,000. In the above description, the term "phenols" means that one or more carbon atoms of the skeleton forming the aromatic ring are directly bonded to a hydroxyl group, and the same structure may have another substituent. Specific examples include phenol, cresol, bisphenol A, resorcinol and the like. Further, formaldehyde is preferably formalin, paraformaldehyde and the like.

The hydroxyl value of the polyol is 20 to 1000 m.
It is selected from gKOH / g according to the purpose. When producing a rigid foam resin, the hydroxyl value of the polyol is
100-1000 mgKOH / g is preferable, 150-
600 mg KOH / g is particularly preferred. When manufacturing a soft synthetic resin, the hydroxyl value of the polyol is 20 to 20.
0 mgKOH / g is preferable and 20 to 100 mgKOH
/ G is particularly preferred.

The isocyanate compound can be obtained by aromatic, alicyclic or aliphatic polyisocyanate having an average of two or more isocyanate groups, a mixture of two or more kinds thereof, and a modification thereof. Modified polyisocyanates may be mentioned. Specifically, tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate (common name:
Examples include polyisocyanates such as crude MDI), xylylene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate, and their prepolymer-type modified products, nurate modified products, and urea modified products.

In the present invention, the active hydrogen compound and the isocyanate compound are reacted in the presence of a catalyst. As the catalyst, a metal compound catalyst such as an organic tin compound, a tertiary amine catalyst such as triethylenediamine, or the like can be used. Also,
A multimerization catalyst for reacting isocyanate groups such as carboxylic acid metal salts can also be used depending on the purpose. Furthermore, a foam stabilizer can be used for good cell formation. Examples of the foam stabilizer include a silicone type foam stabilizer and a fluorine-containing compound type foam stabilizer. In addition, fillers, stabilizers, colorants, flame retardants and the like can be mentioned as optional additives.

The present invention is particularly useful in the production of rigid polyurethane foams, urethane-modified polyisocyanurate foams and other rigid foams, which is a field in which a large amount of halogenated hydrocarbon-based blowing agents is used.

[0024]

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

The following polyols a1 to a5 were mixed in the combinations A1 to A4 shown in Table 1 and used for the following evaluations. The foaming agents were mixed and used in the combination of B1 to B10 shown in Table 2. However, the numbers in Tables 1 and 2 are parts by mass. Polyol a1: hydroxyl value 420 mgKO obtained by reacting propylene oxide with glycerin as an initiator
H / g polyether polyol. Polyol a2: Hydroxyl value 170 mg KO obtained by reacting propylene oxide with glycerin as an initiator
H / g polyether polyol. Polyol a3: A polyether polyol having a hydroxyl value of 350 mgKOH / g, obtained by reacting propylene oxide with a sucrose / monoethanolamine mixed initiator. Polyol a4: Hydroxyl value 440 mgKOH / g obtained by reacting ethylenediamine with propylene oxide
Polyether polyol of. Polyol a5: Hydroxyl number 400 mgKOH / obtained by reacting toluenediamine with 900 parts by mass of propylene oxide and 100 parts by mass of ethylene oxide in this order.
g of polyether polyol.

[0026]

[Table 1]

[0027]

[Table 2]

The evaluation of foaming was carried out as follows. 10K
Polyol 10 selected from A1 to A4 for vat for g
0 parts by mass, water 2 parts by mass, silicone-based foam stabilizer 3 parts by mass,
In addition, N, N-dimethylcyclohexylamine was added as a catalyst in a necessary amount such that the gel time was 60 seconds, and these were well mixed and stirred with a stirrer to give a mixture of about 8 k.
g was obtained. 7 kg of this mixed product was transferred, weighed and filled into a 10 kg cylinder for active hydrogen compound components. 35 parts by mass of a foaming agent selected from B1 to B10 was added to 100 parts by mass of the polyol.

Crude M as an isocyanate compound
Using DI (MR-200 manufactured by Nippon Polyurethane Industry Co., Ltd.), a 10 kg cylinder was similarly weighed and filled.

After the completion of filling, the temperature of the two cylinders of the active hydrogen compound component and the isocyanate compound component was adjusted to 28 ° C. ± 2 ° C., and 300 mm was obtained using a simple foaming device (Asahi Glass Co., Ltd., trade name Auto Floss) × 300 mm × 300 mm
Evaluation was carried out by injecting foam into a wooden box of size. The mixing ratio of the active hydrogen compound component and the isocyanate component was adjusted so that the volume ratio was 1: 1. Of the foam evaluation,
The appearance of the foam was judged by the uniformity and roughness of the cells of the sample injected into this wooden box. Thermal conductivity and dimensional stability were evaluated by pouring a sample into an aluminum mold of 600 mm × 900 mm × 50 mm so that the total density would be 40 kg / m ³ and cutting out a sample of a predetermined size from this. Was carried out.

The compatibility (mixability) between the foaming agent and the polyol component was evaluated using a pressure-resistant transparent glass container. Here, the addition of the foaming agent was performed using a high-pressure injection facility while the pressure-resistant glass container was fixed using a holding tool. The evaluation was performed at 0 ° C. on the basis of ◯: usable without separation or turbidity, Δ: unusable due to turbidity, ×: unusable due to separation.

The appearance evaluation in the foam performance is as follows.
◯: The cell was fine and uniform and had no problem in use, Δ: there was a problem in use due to voids in the foam, and x: the cell was not uniform and was rough and unusable. The dimensional stability in the foam performance was represented by a rate of change (unit:%) with respect to the original thickness that the thickness decreased after 24 hours in an atmosphere of 70 ° C. and 95% relative humidity. The thermal conductivity in foam performance (unit: mW / mK) is based on JIS A-1412, and a thermal conductivity measuring device (Auto Lambda HC074 type,
It was measured using Eiko Instruments Co., Ltd.).

The results are summarized in Tables 3-5. Note that Examples 1 to 23 are Examples and Examples 24 to 31 are Comparative Examples.

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

[Table 5]

[0037]

INDUSTRIAL APPLICABILITY The present invention has an effect that a good foamed synthetic resin can be produced without substantially using CFC or HCFC, which may cause ozone layer depletion.

[Brief description of drawings]

FIG. 1 is a schematic view of the configuration of a simple foaming device used in the present invention.

[Explanation of symbols]

1: Active hydrogen compound 2: Isocyanate compound 3: Gas (nitrogen) 4: Solvent 5: Flow controller 6: Static mixer

Continued front page    F-term (reference) 4J034 CA01 CA03 CA04 CA05 CA14                       CA15 CA16 CC01 CC03 CC11                       CC27 DA01 DB03 DB07 DC02                       DC06 DJ08 HA06 HA07 HA08                       HA09 KB05 NA00 NA01 NA02                       PA05 QC01

Claims (4)

[Claims] 1. A method for producing a foamed synthetic resin, which comprises reacting an active hydrogen compound and an isocyanate compound in the presence of a catalyst and a foaming agent, using a simple foaming device that operates only by operating the pressure of a gas supplied from a gas cylinder. And a fluorinated hydrocarbon containing 1,1,1,3,3-pentafluoropropane and 1,1,1,2-tetrafluoroethane is used as the foaming agent. Manufacturing method. 2. The blowing agent comprises 1,1,1,3,3-pentafluoropropane and 1,1,1,2-tetrafluoroethane in a mass ratio of 20 to 99/1 to 80. The method for producing a foamed synthetic resin according to claim 1, which comprises. 3. The blowing agent comprises 1,1,1,3,3-pentafluoropropane, 1,1,1,2-tetrafluoroethane, and 1,1,1,3,3-pentafluoro. It contains butane, and its ratio is 1,1,1,1, with respect to 100 parts by mass of the total amount of 1,1,1,3,3-pentafluoropropane and 1,1,1,2-tetrafluoroethane.
The method for producing a foamed synthetic resin according to claim 1, wherein the amount of 3,3-pentafluorobutane is 15 parts by mass or less. 4. The blowing agent is 1,1,1,3,3-pentafluoropropane, 1,1,1,2-tetrafluoroethane, or 1,1,1,3,3-pentafluoro. Contains butane in a mass ratio of 40-80 / 19-
It is 50 / 1-15, The manufacturing method of the foaming synthetic resin of Claim 3.