JPS6142549A - Production of phenolic resin foam - Google Patents

Abstract

PURPOSE:To obtain a phenolic resin foam having fine uniform closed cells, by using a polyoxyethylene polyoxyalkylene ricinoleate ether as a foam stabilizer in the production of a foam from a resol type phenolic resin. CONSTITUTION:In the production of a phenolic foam by using a resol type phenolic resin, a blowing agent, a foam stabilizer, a curing agent, etc., 0.1-10pts.wt. polyoxyethylene polyoxyalkylene ricinoleate ether as a foam stabilizer is added to 100pts.wt. phenolic resin. Said ricinoleate ether has the formula [wherein (n) is 10-50; (m) is 5-20; n>=m+5; R is propylene, butylene]. The HLB value thereof varies depending on the quantities of ethylene oxide and alkylene oxide to be added, and is pref. 10-15.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical field to which the invention pertains) The present invention relates to a method for producing a phenolic resin foam having closed cells and a uniform fine cell structure.

Phenolic resin foams are used for various purposes due to their excellent properties such as fire resistance and heat insulation. Generally, methods for producing phenolic resin foam include a method using a mixture of a novolac type 7-nol resin and hexitemethylenetetrimine, and a method using a mixture of a resol type funol resin mixed with a blowing agent, a surfactant, and an acidic curing agent. etc. are known.

The present invention relates to a method for producing a phenolic resin foam using a resol-based phenol resin.

(Prior Art) Resol-based phenolic resins can generally be produced by reacting a phenolic compound and an aldehyde compound under controlled reaction conditions and in the presence of a controlled excess amount of the aldehyde compound. Foaming is performed by mixing a certain amount of a foaming agent, a foam stabilizer, and a hostile curing agent with a resol type phenolic resin, and applying a temperature of room temperature or 40 to 120°C.

The 7-nol resin foam thus obtained is generally believed to have about 40 to 100 open cells. This is caused by destruction of the cell walls and cracks in the center of the foam due to eyes, voids, etc.

As an improvement on the above problems, JP-A-56-304
There are 38. This involves adding N-methyl-2-pyrrolidone to obtain uniform cells.

(Problems to be Solved) However, although the phenol resin foam obtained in the presence of 1J-methyl-2-pyrrolidone had some effect of making the cells uniform and fine, it was unsuccessful because many continuous cells were present.

As a result of intensive research to obtain a phenolic resin foam having closed cells and a uniform fine cell structure, the present inventors discovered that polyoxyethylene polyoxyalkylene ricinoleate ether was added as a foam stabilizer in a specific proportion. It has been discovered that the phenolic resin foam, which is the object of the present invention, can be obtained by mixing the phenol resin foams.

(Structure of the Invention) That is, the present invention uses polyoxyethylene polyoxyalkylene ricinol as a foam stabilizer to produce a 7-nol resin foam from a blowing agent, a foam stabilizer, a curing agent, etc. other than resol type phenol. This is a method for producing a phenolic resin foam, characterized in that 1 to 10 parts by weight of acid ether is added to 100 parts by weight of a resol type phenolic resin.

The polyoxyethylene polyoxyalkylene ricinoleic acid ether used in the present invention has the following structural formula: % n≧m -) -5R = propylene or butylene Depending on the amount of ethylene oxide and alkylene oxide, the water resistance and hydrophobicity may vary. strength balance (HLB)
However, the HLB of polyoxyethylene polyoxyalkylene ricinol ex-thyl used in the present invention is:
Although it varies depending on the type of resol type phenolic resin, a5
~17.5, preferably 10-15.

The amount of the foam stabilizer to be used is preferably 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the resol type 7 enol resin. If it exceeds 10 parts by weight, it will become 7 ohm with a closed-cell fine cell structure, but it is not preferable because it will reduce mechanical strength, heat resistance, and fire resistance.
When the amount is less than 1 part by weight, a foam having a uniform fine cell structure of closed cells cannot be obtained.

As the phenol compound or aldehyde compound used in the production of the resol type phenolic resin, individual compounds can be used. Phenolic compounds include both phenol and its congeners such as cresol and xylenol or mixtures of these compounds. Aldehyde compounds that react with phenolic compounds include, for example, formaldehyde, acetaldehyde, furupral, and other aldehydes and mixtures of these compounds. Additionally, aldehyde-generating compounds can also be used, such as paraformaldehyde, hexamethylenetetramine, methylol, trioxane,
Compounds that decompose to formaldehyde, such as tetraoxymethane and others, and mixtures of these compounds can also be used.

The reaction between phenolic compounds other than phenol and aldehydes other than formaldehyde or its complex forms is slower than the reaction between phenol and formaldehyde. Therefore, in the present invention, it is preferable to use a resol type phenol resin in which phenol and formaldehyde are reacted.

The blowing agent that can be used in the present invention has a boiling point of about -40°C.
Chlorinated and fluorinated hydrocarbons at ~100°C, such as chloroform, methylene chloride, trichlorofluoromethane,
Tetrafluoromethane, 1゜1.2-trichloro-1,
2,2-)lifluoroethane, monochlorodifluoromethane, dichlorodifluoromethane, 1,1-dichloro-
1,2,2,2-tetrafluoroethane, 1.2-dichloro-1,1°2.2-tetrafluoroethane, 1.1
．． l-1! jchloro-2,2,2-)lifluoroethane, 1,2-difluoroethane, promotrifluoroethane, 1.1.2.2-tetrachloro-1,2-difluoroethane, 1.1.1.2- Included are tetrachloro-2,2-difluoroethane or mixtures of these compounds.

As the curing agent used in the present invention, mineral acids such as sulfuric acid, hydrochloric acid, and phosphoric acid, and organic acids such as P-toluenesulfonic acid and phenolsulfonic acid are used. By shifting the pH of the neutral resol-based phenolic resin all at once to the acidic side, condensation immediately begins, and foaming begins in the presence of the foaming agent.
It is preferable to use the polyoxyethylene polyoxyalkylene ricinoleic acid niterol of the present invention by blending it into a resol type phenolic resin. To mix and foam the resol type 7-mer resin containing polyoxyethylene polyoxyalkylene ricinoleic acid ether and other raw materials, any method may be used as long as the reaction mixture can be mixed uniformly. For example 1,500
~10, can be obtained with a known mixing device such as a gear type or pinya mixer at OO○ rpm.

(Effects of the Invention) The 7-nol resin foam obtained by the present invention has the following characteristics.

(1) Compared to conventional resol-based phenolic resin foams, it has a higher closed cell ratio and exhibits excellent heat insulation performance.

(2) The center of the foam has no holes or voids and has a uniform fine cell structure, so it has a high mechanical strength of 7 ohms.

(3) There is little influence on foam foaming and curing, and foaming can be performed using normal methods.

(4) It has flame retardancy, low smoke emission, and heat resistance equivalent to conventional phenolic resin foam.

As described above, the resol-based phenolic resin foam according to the present invention has closed cells, has a uniform fine cell structure, and has excellent heat insulation properties, heat resistance, and flame retardancy, and therefore can be widely used in the field of building materials.

(Examples and Comparative Examples) Next, the present invention will be specifically explained using Examples, but the present invention is not limited to these Examples.

Examples 1 and 2 The reaction mixture shown in Table 1 was weighed into an IL polyethylene beaker, and stirred vigorously for 10 to 30 seconds with a mixer (rotation speed: 8000 rpm) at room temperature (20 to 25°C).
It was foamed in an aluminum mold with an open top heated to 0°C to 80°C and cured for about 10 minutes in an oven at 80°C to 120°C to obtain a resol-based phenolic resin foam. After dehydration for two weeks at room temperature, 7 ohm physical properties were measured. Compared to Comparative Example 1 in which a silicone surfactant was used as a foam stabilizer, the closed cell ratio was higher and the thermal conductivity was lower. Further, visual inspection revealed that there were no cracks or large voids in the center of the foam, and that it had a uniform and fine cell structure.

Examples 3 and 4 The mixture shown in Table 1 was treated in the same manner as in Example 1 to obtain a resole type 7-nol ati 7 ohm.

Compared to Comparative Example-2, the closed cell ratio was higher.

Moreover, the heat resistance at 150°C was also good. Visual inspection revealed that the cell structure was uniform and fine.

Examples 5 and 6 The mixture shown in Table 1 was treated in the same manner as in Example 1 to obtain a 7 ohm resol type Funol resin. High closed cell ratio,
The cell structure was uniform and fine, 7 ohms.

Comparative Example-1 The resole-based Funol resin foam obtained from the mixture shown in Table-1 not only had a lower closed cell ratio than Example 1.2, but also had larger cells as a result of visual inspection, indicating that the cell structure was poor. There were 6 uneven pieces.

Comparative Example-2 The resol-based phenolic resin foam obtained from the mixture shown in Table-1 not only had no closed cells at all, but also
The cell structure was also uneven and rare.

Comparative Example 3 As a result of using N-methyl-2-pyrrolidone as a foam stabilizer, the cell structure became uniform and fine, but there was no increase in closed cells.

The blending amount numbers in the table indicate parts by weight.

Foam stabilizer-A: Polyoxyethylene polyoxypropylene ricinoleic acid ether (HIJB=12) Foam stabilizer-B: Polyoxyethylene polyoxybutylene ricinoleic acid ether (HIIB=12) 7=-Nol resin-A: Viscosity Phenol, formaldehyde (resol type phenol) resin Phenol resin-B: Viscosity is 1000 cp/visible at 25°C, solid content is 75 cm. Phenol, formaldehyde (resole phenol) resin Silicone surfactant (foam stabilizer): Toray Silicone 5H-193 Foaming agent Nitrichlorotrifluoroethane Hardening agent: 65 thiefylnorsulfonic acid aqueous solution 7 ohm Density:
, Tl5A-9514 Measured compressive strength: J Engineering 5A-
Brittleness measured by 9514: ASTMC-421
The smaller the measured value, the less brittle the foam is.

Closed cell ratio: Measured according to ASTM D-2856 Thermal conductivity: Measured according to J Engineering 5A-9514 Smoke generation coefficient: 220
J-engineering 5A-13 using a test piece of X220X30r*
According to the 21 flame retardant grade 2 surface test, the smaller the measured value, the lower the amount of smoke emitted.

Heat resistance: 15 test pieces of 100x100x50
Leave it in an oven at 0℃ for 24 hours and measure deformation, cracks, etc.

Features less deformation and no cracks to be

Claims (1)

[Claims] When producing phenolic resin foam from resol-based phenolic resin, blowing agent, foam stabilizer, curing agent, etc., polyoxyethylene polyoxyalkylene ricinoleic acid ether is added as a foam stabilizer to 100 parts by weight of resol-based phenolic resin. A method for producing a phenolic resin foam, which comprises adding 0.1 to 10 parts by weight.