JPH01139613A - Production of expanded synthetic resin - Google Patents

Abstract

PURPOSE:To obtain the title excellent resin without a fear of destroying the ozonosphere, by reacting an active hydrogen compound with a polyisocyanate compound using a chlorotrifluoroethane as a foaming agent. CONSTITUTION:(A) An active hydrogen compound (e.g., phenolic resin precondensate) having >=2 active hydrogen-containing functional groups reactive with isocyanate groups is reacted with (B) a polyisocyanate compound (e.g., tolylene diisocyanate) in the presence of (C) a low-boiling halogenated hydrocarbon based foaming agent to produce an expanded synthetic resin. In the process, preferably 20-60wt.% [based on the component (A)] 1-chloro-1,2,2- trifluoroethane is used as the component (C).

Description

Detailed Description of the Invention [+71 Field of Industrial Application] The present invention relates to a method for producing foamed synthetic resin such as polyurethane foam, and in particular to a method for producing foamed synthetic resin, which is characterized by the use of a specific blowing agent. The present invention relates to a method for manufacturing Noh.

[Prior Art] It is widely practiced to produce a foamed synthetic resin by reacting an active hydrogen compound having two or more active hydrogen-containing groups capable of reacting with an isocyanate group with a polyisocyanate compound in the presence of a catalyst and a blowing agent. It is. Examples of active hydrogen compounds include polyhydroxy compounds and polyamine compounds. Examples of the resulting foamed synthetic resin include polyurethane foam, polyisocyanurate foam, and polyurea foam. Examples of foamed synthetic resins with relatively low foaming properties include microcellular polyurethane elastomer and microcellular polyurethane urea elastomer.

Although various compounds are known as blowing agents for producing the above-mentioned foamed synthetic resin, trichlorofluoromethane (R-11) is mainly used. Also, usually R-
Water is further used in combination with 11. Furthermore, when foaming is performed using the floss method, etc., dichlorodifluoromethane (which has a lower boiling point and is a gas at normal temperature and normal pressure) is used together with these.
I't-12) is used in combination. Furthermore, various proposals have been made that other relatively low-boiling point chlorinated fluorinated hydrocarbons can be used as blowing agents, but with the exception of R-11 and R-12 mentioned above, they are still widely used. It has not yet reached the point where it will be done. It has also been proposed to use other low boiling point halogenated hydrocarbon blowing agents such as methylene chloride in place of the chlorinated fluorinated hydrocarbon blowing agents.

[Problems to be solved by the invention] Chlorinated fluorinated hydrocarbons that are extremely stable in the atmosphere, such as R-11 and R-12, which have been widely used in the past, can reach the ozone layer above the atmosphere without decomposing. It is now thought that the decomposition products may destroy the ozone layer when they reach such a point that they are decomposed by the action of ultraviolet light. Chlorinated fluorinated hydrocarbons such as those mentioned above used as blowing agents,
Because some of it leaks into the atmosphere, there are concerns that its use could be part of the cause of ozone layer depletion. Therefore, in place of R-11 and +1-12, it is desirable to develop a blowing agent that is less likely to cause ozone layer depletion.

[Means for Solving the Problems] The present invention provides the following inventions to solve the above-mentioned problems.

2 active hydrogen-containing functional groups that can react with isocyanate groups
In the method of producing a foaming synthetic resin by reacting an active hydrogen compound having the above and a polyisocyanate compound in the presence of a low boiling point halogenated hydrocarbon blowing agent, 1-chloro -1°2.
A method for producing foamed synthetic resin, characterized by using 2-trifluoroethane. The blowing agent in the present invention, 1-chloro-1,2,2=trifluoroethane, has a boiling point of 1
Since it is a compound with a temperature of 7°C and is a chlorinated fluorinated hydrocarbon containing hydrogen atoms, it is thought that there is little risk of the ozone layer being destroyed. Furthermore, since its boiling point is close to that of R-11, it can be used as a blowing agent in place of R-11.

The halogenated hydrocarbon blowing agent in the present invention can be used alone or in combination with other blowing agents. In particular, water is often used in combination with the halosaponated hydrocarbon blowing agent. Other blowing agents that can be used in combination with water include, for example, the current blowing agents II-II and R.
-12, other low-boiling halogenated hydrocarbons, low-boiling hydrocarbons, and inert gases. Although R-11 and R-12 themselves may cause ozone layer destruction, their usage can be reduced without reducing their usage by using them in combination with 1-chloro-1,2,2-trifluoroethane. Other low-boiling halogenated hydrocarbons include halogenated hydrocarbons that do not contain fluorine atoms, such as methylene chloride, and fluorine-containing halogenated hydrocarbons other than those mentioned above. Low-boiling hydrocarbons include butane and hexane, and inert gases include air and nitrogen.

2 active hydrogen-containing functional groups that can react with incyanate groups
The active hydrogen compound having the above is a compound having two or more active hydrogen-containing functional groups such as a hydroxyl group or an amino group, or a mixture of two or more such compounds. Particularly preferred are compounds having two or more hydroxyl groups, mixtures thereof, or mixtures containing the same as a main component and also containing boamine or the like. As the compound having two or more hydroxyl groups, widely used polyols are preferred, but compounds having two or more phenolic hydroxyl groups (eg, phenol resin initial condensate) can also be used. Polyols include polyether polyols, polyester polyols,
Examples include polyhydric alcohols and diethylene polymers containing hydroxyl groups. In particular, it is preferable to use only one or more types of polyether polyols, or to use them as a main component in combination with polyester polyols, polyhydric alcohols, polyamines, alkanolamines, and other active hydrogen compounds. The polyether polyol is preferably a polyether polyol obtained by adding a cyclic ether 4, particularly an alkylene oxide such as propylene oxide or ethylene oxide, to a polyhydric alcohol, saccharide, alkanolamine, or other initiator. In addition, as polyols, vinyl polymers are mainly used in polyether polyols called polymer polyols or graft polyols.
It is also possible to use polyol compositions containing branched microparticles. Polyester polyols include polyhydric alcohol-polycarboxylic acid condensation polyols and cyclic ester ring-opening polymer polyols, and polyhydric alcohols include ethylene glycol, propylene glycol,
These include diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol, jetanolamine, and triethanolamine. The hydroxyl value of the polyol or its mixture is approximately 2
It is often selected from 0 to 1000 depending on the purpose.

Examples of polyisocyanate compounds include aromatic, alicyclic, or aliphatic polyisocyanates having two or more isocyanate groups, mixtures of two or more thereof, and modified polyisocyanates obtained by modifying them. Specifically, for example, polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenylisocyanate (commonly known as crude MDI), xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and prepolymer-type modified products thereof; There are nurate modified products, urea modified products, etc.

When reacting active hydrogen compounds and polyisocyanate compounds, the use of catalysts is usually required. As a catalyst,
Metal compound catalysts such as organotin compounds and tertiary amine catalysts such as triethylenediamine are used, which promote the reaction between active hydrogen-containing groups and incyanate groups. Further, a polymerization catalyst that causes isocyanate groups to react with each other, such as a carboxylic acid metal salt, is used depending on the purpose. Furthermore, foam stabilizers are often used to form good foam. Examples of the foam stabilizer include silicone foam stabilizers and fluorine-containing compound foam stabilizers. Other optional additives include fillers, stabilizers, colorants, flame retardants, and the like.

Using these raw materials, polyurethane foam, urethane-modified polyisocyanate foam, microcellular polyurethane elastomer, microcellular polyurethane urea elastomer, microcellular polyurea elastomer, and other foamed synthetic resins can be obtained.

Polyurethane foam can be broadly divided into rigid polyurethane foam, semi-rigid polyurethane foam, and flexible polyurethane foam. The present invention is particularly useful in the production of rigid polyurethane foam, urethane-modified polyisocyanurate foam, and other rigid foams, which are fields in which halogenated hydrocarbon blowing agents are used in large quantities. It is particularly useful in the production of rigid polyurethane foams obtained using polyols or polyol mixtures of about 200 to 1000 and aromatic polyisocyanate compounds. When producing these hard foams, the amount of the halogenated hydrocarbon blowing agent used in the present invention is 5 to 15% based on the active hydrogen compound.
0% by weight, especially 20-60% by weight is suitable. Also,
At the same time, water is added to the active hydrogen compound from 0 to 10 f.
It is preferable to use 1% of fiff, especially 1 to 5% by weight. On the other hand, in the case of flexible polyurethane foam, semi-rigid polyurethane foam, and microcellular elastomer, the halogenated hydrocarbon blowing agent in the present invention is preferably used in an amount of 5 to 150% by weight based on the active hydrogen compound.

In the case of soft urethane foam and semi-rigid urethane foam, it is preferable to use 0 to 10% by weight of water, and in the case of microcellular elastomer, it is preferable to use 0 to 5% by weight of water.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.

[Actual h'fi Example] Foaming evaluation of the halogenated hydrocarbon foaming agent in the present invention was conducted for the following polyols.

Polyolumi: A polyether polyol with a hydroxyl value of 420 made by reacting glycerin with propylene oxide Polyol B: A polyether polyol with a hydroxyl value of 450 made by reacting sucrose with propylene oxide and ethylene oxide Polyol C: Propylene oxide with toluene diamine The foaming evaluation of polyether polyol having a hydroxyl value of 440 was carried out as follows. For 100 parts by weight of polyol, silicone foam stabilizer (Shin-Etsu Chemical ■ trade name)
A mixture of 2 parts of F-338), 1 part of water, the necessary amount of N,N-dimethylcyclohexylamine as a catalyst to give a gel time of 45 seconds, and an appropriate amount of 1-chloro-1,2,2-)lifluoroethane. Mix the liquid and polymethylene polyphenylisocyanate (MD Kasei ■ trade name PAP1135) at a liquid temperature of 20°C, 200 + nm x 200 mm x 20
It was placed in a 0 mm wooden box and evaluated by foaming.

Further, as a comparative example, n-tt was similarly foamed and evaluated.

The amount of foaming agent used is based on the core density of the foam being 30±2kg.
/m'.

The results are shown in Table 1.

The criteria for judgment are as follows.

Q: Equivalent or better than It-It △: Slightly inferior to n-tt x: Inferior to 11-11 Table 1 Polyol a b Type of C Compatibility with polyol OQ △ Form appearance ○ △ 0 Core density
29.1 30.8 28.2 Compressive strength
○ △ can be manufactured.

Claims (1)

[Claims] 1. Foaming synthesis 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 low-boiling halogenated hydrocarbon blowing agent. 1. A method for producing a foamed synthetic resin, the method comprising using 1-chloro-1,2,2-trifluoroethane as a low-boiling halogenated hydrocarbon foaming agent.