JPH0583574B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a resol-type phenolic resin foamable composition that is required to have fast curing, low odor, and low shrinkage. [Prior art] Generally, resol type phenolic resin using phenols and aldehydes is used to produce resol type phenolic resin foam, and a surfactant, a blowing agent, and an acid curing agent are mixed with this. It is manufactured at ambient temperatures ranging from room temperature to 100°C. Factors that determine the curability of a resol type phenolic resin foam include the characteristics of the resol type phenolic resin, temperature, the type of acid curing agent, and the amount used, all of which have important significance. Conventionally, in order to improve the curing speed in the production of resol type phenolic resin foams, the main methods were to adjust the temperature, to use inorganic acids such as sulfuric acid and hydrochloric acid in combination with organic acids such as toluenesulfonic acid and phenolsulfonic acid, and to control the amount used. Although these problems have been addressed through adjustment, it is difficult to obtain a satisfactory foam using only these measures. In addition, a method has been proposed in which a resol type alkyl phenol resin is pre-reacted with resorcin and this is used in combination with a resol type phenol resin (Japanese Patent Application Laid-Open No. 1983-95038), but this method does not work well when improving the curing speed. The same measures as above must be taken, and even if such measures are taken, it is difficult to obtain a satisfactory foam. Furthermore, a method has been proposed in which an aqueous solution or solid resorcin is added to a resol-type phenolic resin (Japanese Patent Publication No. 46-41712), but in this method, resorcin has a high reaction ability with a resol-type phenolic resin, and even at room temperature. Due to the formation of a network structure, the stability is significantly deteriorated and its use is difficult. [Problems to be Solved by the Invention] When making a resol type phenolic resin a fast-curing type, examples include raising the temperature, increasing the amount of acid curing agent, and using a stronger acid. A large amount of aldehyde and water vapor are released, and this odor worsens the working environment. Furthermore, there is a problem in that the foam is deformed due to primary shrinkage, and a large amount of residual acid in the foam corrodes other members. Therefore, in the field of phenolic resin foams that require fast curing properties, problems such as odor that worsens the working environment and deformation of the foam due to shrinkage occur, making it impossible to obtain a suitable foam. The present invention aims to provide a resol type phenolic resin foaming composition which eliminates the above-mentioned drawbacks and is required to have fast curing properties. [Means for Solving the Problems] That is, the present invention provides a phenolic resin foamable composition comprising a resol type phenolic resin mixed with a surfactant, a blowing agent, and an acid curing agent. A resol-type resorcinol-based phenolic resin selected from a resol-type resorcinol resin, a resol-type resorcinol-based phenolic resin, or a mixture of these resins and a resol-type phenolic resin is used as the resol-type resorcinol-based phenolic resin, and the resorcin content in the resol-type resorcinol-based phenolic resin is 2.
By using it at ~60% by weight,
The present invention was achieved by discovering that a foam can be obtained that has good resin storage stability, increases the foam curing speed, and does not generate a large amount of odor or change in shrinkage of the foam. [Function] The action of the resorcinol-based phenolic resin using resorcin and aldehydes used in the present invention is that it has phenolic hydroxyl groups at the 1st and 3rd positions in its molecular structure, so it reacts at the ortho and bala positions. This makes the cross-linking polymerization reaction faster, and it also reacts with aldehyde generated during the reaction.
It is also thought that the density of crosslinking points increases, thereby suppressing primary shrinkage. However, if the amount of resorcin in the resin is less than 2% by weight, which is within the scope of the present invention, the effect cannot be expected. The same applies when the amount exceeds 60% by weight, and the primary shrinkage is particularly noticeable. The resol-type resorcinol-based phenolic resin of the present invention includes a resol-type resorcinol resin in which resorcinol and aldehydes are condensed, a resol-type resorcinol-phenolic resin in which phenol is co-condensed with the resol-type resorcinol resin, and a mixture of these resins and a resol-type phenolic resin. meaning, resorcinol 2-60% by weight
is the content of resorcinol in the resin or resin mixture. The resol-type resorcinol resin using resorcin and aldehydes used in the present invention is prepared by adding 1.5 to 3 mol of aldehyde to 1 mol of resorcin in the presence of an alkali metal or alkaline earth metal catalyst at a temperature of preferably 10 to 100°C. At 20-80℃, 1-
After reacting for 7 hours, preferably 2 to 5 hours, the pH is neutralized to 4.0 to 8.0 with an inorganic or organic acid. Thereafter, water in the system is removed to an appropriate amount by dehydration under reduced pressure. Suitable aldehydes used in the reaction with resorcinol include formaldehyde, paraformaldehyde, polyoxymethylene, trioxane, and the like. The blowing agents used in the present invention include pentane, methylene chloride, trichlorofluoroethane,
Examples include volatile organic liquids such as tetrafluoromethane and 1,1,2-trichloro-1,2,2-trifluoroethane. Of course, these may be used as a mixture. These blowing agents are used in amounts of 5 to 100 parts by weight of resin.
It is desirable to use within the range of 40 parts by weight. Examples of the surfactant used in the present invention include surfactants such as silicone-based ethylene oxide, propylene oxide copolymer, sorbitan, alkylphenol, and polyoxyalkylene adducts such as castor oil. These can also be used in combination, and the amount used depends on the resin.
It can be used in a range of 0.5 to 10 parts by weight per 100 parts by weight. The acid curing agent used in the present invention includes sulfuric acid,
Examples include inorganic acids such as hydrochloric acid, and organic acids such as toluenesulfonic acid and phenolsulfonic acid. These can also be used as a mixture, and the amount used can range from 5 to 100 parts by weight, preferably from 10 to 50 parts by weight, based on 100 parts by weight of the resin. The resol type phenolic resin foam in the present invention uses a resol type resorcinol phenolic resin so that the resin contains 2 to 60% by weight as resorcinum, and after mixing a surfactant, a blowing agent, and an acid curing agent. , the foam is cured to produce a foam. Mixing may be performed using a high-speed stirrer (such as Homo Disper) for 2 to 60 seconds in accordance with the curing reaction, or may be mixed by spraying, such as spray foaming or in-situ foaming. However, if the surface to which it is applied has a certain angle, if the sprayed resol type phenolic resin foam composition is not foamed and cured immediately, it will sag (the foamable resin composition moves downward) and the foam will not be properly formed. is not obtained. When the resol type phenolic resin foamable composition of the present invention is used, the curing speed becomes faster and problems such as odor and shrinkage can be easily solved. Foaming hardens at room temperature
Performed at an ambient temperature of 100°C. [Example] The following is a concrete explanation using an example. Example 1 A four-necked flask was charged with 2.0 kg of phenol, 2.93 kg of 37% formaldehyde (mole ratio 1.7 mol), and 60 gr of 20% caustic soda as a catalyst, and after reacting at 80°C for 3 hours, the pH was adjusted to 7.0 using 15% sulfuric acid. The water content in the resin was reduced to 5% or less by dehydration under reduced pressure. The obtained resol type phenolic resin has a resin solid content of 80%, a viscosity of 3000 cps/25°C, and a weight average molecular weight of 430.
This was used as resin A. Furthermore, 2.0Kg of resorcinol, 37% in a four-necked flask.
2.51 kg of formaldehyde (mole ratio 1.7 mol) and 60 gr of 20% caustic soda as a catalyst were prepared and heated at 40°C.
After reacting for an hour, the pH was neutralized to 7.0 using 15% sulfuric acid, and the water content in the resin was reduced to 10% or less by dehydration under reduced pressure. The obtained resol type resorsi resin has a resin solid content
75%, viscosity 3000 cps/25°C, weight average molecular weight 480, and was used as resin B. Resin A 50 parts by weight, Resin B 50 parts by weight,
2 parts by weight of Tween #40 (polyoxyethylene sorbitan palmitate), 1,1,2- as a blowing agent
Trichloro-1,2,2-trifluoroethane 20
parts by weight and further 20 parts by weight of 65% phenolsulfonic acid were stirred for 10 seconds with a high-speed stirrer (4000 to 6000 rpm), and then placed in a plastic bag with a width of 50 cm and a length of 80 cm.
This was left to stand at room temperature (atmosphere 25°C) to complete foaming and curing to obtain a resol type phenolic resin foam. The odor generated by foam curing was measured using a Kitagawa detection tube, and the concentrations of formaldehyde and phenol in the plastic bag were each below 1 ppm.
It was 0.8ppm. Further, the shrinkage rate (length at the end of foaming and curing x 100/length after 1 day) was 2.2%. Table 1 shows the above results.

【table】

[Table] Examples 2 to 4, Comparative Examples 1 to 8 In the method of Example 1, foams were produced under the conditions shown in Table 1, and their physical properties were measured. Example 5 1.0Kg of phenol and resorcinol in a four-necked flask
1.0Kg, 37% formaldehyde 2.72Kg (molar ratio 1.7
mol) and 60g of 20% caustic soda as a catalyst, reacted at 80℃ for 3 hours, and then adjusted the pH using 15% sulfuric acid.
Neutralize to 7.0 and remove water in the resin by vacuum dehydration.
% or less. The obtained resol type phenolic resin has a resin solid content of 80%, a viscosity of 2800 cps/25°C, and a weight average molecular weight of 460.
This was used as resin C. A foam was produced from the obtained resin C according to the method of Example 1 under the conditions shown in Table 1, and the physical properties were measured. Comparative Example 9 A phenolic resin was produced according to Example 1 described in JP-A-61-95038, and the resulting resin was used as Resin D to produce a foam in the method of Example 1 under the conditions shown in Table 1. It was manufactured and its physical properties were measured. Example 6 The resin, foaming agent, and surfactant were mixed in advance according to the formulation of Example 1, and a two-component system was used using an actual spray machine (Hydracat VRHC manufactured by GRACO), with a width of 50 cm, a length of 100 cm, and an angle of 45°. The foam was discharged for 30 seconds (approximately 1 kg) onto a plasterboard. The results are shown below.

【table】

〔Effect of the invention〕

As is clear from Table 1, the resol-type phenolic resin foamable composition of the present invention has good resin storage stability, improved foam curing time, and also has no odor caused by the short foam curing time. ,Shrinkage factor)
I can't see it. Moreover, since the conventional foam curing time can be easily improved, the line speed in conventional manufacturing machines can be increased and production can be performed by spray foaming or on-site foaming. Therefore, it has become possible to use it more widely in the future for building materials, furniture, etc.

Claims (1)

[Claims] 1 Surfactant, resol type phenolic resin,
In the phenolic resin foamable composition containing a blowing agent and an acid curing agent, the resol type phenolic resin includes a resol type resorcinol resin,
A resol type resorcinol phenolic resin selected from a resol type resorcinol phenolic resin or a mixture of these resins and a resol type phenolic resin is used, and the resorcin content in the resol type resorcinol phenolic resin is 2 to 60% by weight. A resol type phenolic resin foamable composition characterized in that it is used for.