WO1982003629A1 - Process for manufacturing urea resin foam - Google Patents

Abstract

Conventional processes for manufacturing urea resin foams fail to cause uniform foaming, and thus the resulting foams are fragile and easily contract. This process comprises compounding a urea resin preferably modified with epsilon -caprolactam, polyhydric alcohol, or the like, with resorcinol and/or furfuryl alcohol, and expanding the resulting mixture. This process produces uniform expansion and provides urea resin foams having high strength, low contraction, and uniform cells. The resulting foams are useful as thermal insulating materials and wrapping materials.

Description

 Specification

 Name of the invention

 Manufacturing method of urea resin foam

 Technical field

 The present invention belongs to the technical field of manufacturing plastic foams, specifically, urea resin foams. Therefore, basically, the production of the resin used as the raw material of the foam, specifically, the technical field of production of urea resin, and more generally, the production of thermosetting resin Belongs to the technical field.

 On the other hand, from the point of view of use, it also belongs to the technical fields of heat insulating materials, sound absorbing materials, packaging materials, and agricultural materials.

Background technology

 Urea resin foam (hereafter, “uriaform”) is used in various fields, such as heat insulating materials, sound absorbing materials, anti-condensation agents, packaging buffer materials, and plant cultivation beds. Yes.

 Due to their favorable properties, demand for demand is steadily increasing. In addition to the increasing use and demand, the quality and characteristics required of the urium arm have also increased, and improvements have also been made in the manufacturing method. It was pointed out that there was room for this.

 The way in which Uriforms are manufactured depends on the force with which the resulting form is turned to the intended use. For example, when filling a building wall and using it as a heat insulator, at the construction site, foam the urea resin liquid into the voids of the wall and inject it. Then, a method of hardening with a force that fills the voids is adopted. Also,

one. ?,: Η ―, For example, when producing plate-shaped or block-shaped Uriform, it is possible to use a casting method or any other type of mold. A method of obtaining a lump-shaped form and cutting out a form having a predetermined shape is employed.

 In addition, if we classify the method of producing a urform from another point of view, it is possible to foam a hardener solution with a surfactant or the like and mix it with a urea resin solution. The method can be classified into a method in which the foam is fixed by hardening the urea resin in the first place, and a method in which a foaming agent and a curing agent are added to the urea resin liquid to cause foaming and hardening. In particular, the former is used for the construction method that fills voids in the wall.

 The problems with the conventional thread form obtained as described above are as follows, for example.

 First, the strength is low. In the conventional Uriform, the surface is chipped in powder form only by playing with the lump in the hand, and the surface becomes thinner as soon as possible. It explains the drawback that the form as a form is difficult to maintain during handling. In particular, when the expansion ratio was set to a high value, the above-mentioned drawbacks were remarkably exhibited, and the strength was significantly reduced.

Another problem is that the volume shrinks over time without any external stress or shock. It is fingered. For example, even if it is filled into a wall panel as heat insulating material, voids will form over time and the heat insulating effect will be diminished over time. Even that happens. This is thought to be due to the gradual extraction of the urine forming power and the water it contains. Therefore, under heating Or, if the foam is well-ventilated, the shrinkage of the volume will be further promoted.

 Next, there are manufacturing problems

 One of the manufacturing problems is that the stability of the resin is poor. In other words, if the adjusted urea resin is stored, the crystals of methyl urea will precipitate out or the whole resin will be solidified. Not only the problem of resin stability, but also the problem of not being able to secure the appropriate resin viscosity required during foaming is also linked to S '. This made it difficult to achieve stable high-ratio expansion. Another problem with the production method is that, in the latter method, in which urea resin is directly foamed, the resin foaming speed and curing speed are controlled by a balance. It is very difficult to control well, and it is important to mention that it is difficult to perform stable foaming. It was thought that this was the cause of the inability to obtain a uniform form.

Disclosure of the invention

Under the circumstances described above, the present invention provides a method for improving the stability of urea resin or a foamed state in the production of a urethane foam, and improving the stability of the foam itself. The purpose was to improve the performance of the. Further, the present invention is more preferable by blending the urea resin with a substance, which is also referred to as a foam fixing agent, to foam the urea resin. The above object has been achieved by blending a foaming fixative with a specially modified urea resin and foaming. Hereinafter, the present invention will be described in detail. In the present invention, the main constituent of the urform is a urea resin. A urea resin is a resin obtained by reacting urea with honolean aldehyde in the presence of an acid or alkaline catalyst (often an alkaline catalyst). However, usually, what is called an initial condensate is used.

The source of formaldehyde for reacting with urea is a mixture of honolemarin and honolem T-nordealdehyde dissolved in organic solvents at a high concentration. , Or No, ⁰ La Honorem is used. In the present invention, it is preferable to use a resin solution having a low water content and a high concentration, as described later, as the resin solution used in the present invention. To obtain the liquid, for example, c. It is preferable to use a highly concentrated formaldehyde source, such as Lahosolem O

 Known techniques can be used to obtain the precondensate, but in some cases, the desired resin solution can be obtained without using any catalyst. Wear . In particular, when using paraholenes, the reaction system can be kept in a preferable PH range without any catalyst. For example, caustic soda, caustic soda, sodium carbonate, carbonated carbonate, magnesium hydroxide, which is a well-known Al catalyst, may be used. No known anolyte catalysts such as aluminum, magnesium oxide, zinc hydroxide, ammonium, and amines; formic acid, phosphoric acid, or Weakly acidic catalysts such as the salts of these or pH control in the weakly acidic range

— A buffer or other buffer is used to remove oil

 The pH of the reaction is preferably about 5.5.80, and more preferably about 6.0.

 7.0, more preferably 6.5 to 6.7. Extremely acidic

c:.:? i. If the reaction is carried out on the reaction side, or if the reaction is carried out on the extremely alkaline side, there is no reaction system, Crystals precipitate and become cloudy, or the whole solidifies. Otherwise, it is not easy to use as a resin for the production of polyurethane foam unless it is kept in such a way. In order to prevent such troubles, it is desirable that measures have been taken to obtain a resin with good stability. For example, as used in the present invention, honolealdehyde is used in an amount of 1.3 to 3.9 moles, preferably 1 mole, per mole of urea, as used in the present invention. Based on the method of condensation reaction under weak acidity or alkalinity using mono-ole, e-strike program or polyvalent The alcohol modifies the urea resin.

Polyhydric alcohols used as denaturing agents include, for example, ethylene glycol, polyethylene glycol, propylene, and the like. These include Lenco-core, Glycerin, and Pentaerythrill. Among them, polyethylene glycol is preferred. These multi-functional cameras can be used in conjunction with _£ -force programs, or they can use either of the two. . When used in combination, the stability of the resin solution is further enhanced. The amount used is 0.1 to 2.0, preferably 0.5 to 1.0, mol per mol of e-force s' urea. On the other hand, the polyhydric alcohol mixes 3 to 20% by weight (hereinafter simply referred to as%), preferably 5 to 10% with respect to the resin solution.

The time for adding the denaturing agent may be after the reaction, but it is preferable to add it during the reaction. More preferably, the method is This is done by previously reacting or mixing the urea with a part of the urea and then adding the remaining or all of the urine later. When param- um is used as a source of formaldehyde, the reaction system becomes solid, so e-force pro- gram or multivalent It is convenient to dissolve the oleoresin at the beginning of the reaction or before dissolving it in the raw material of the formaldehyde source and then subjecting it to the reaction with urea.

 The reaction temperature is 40 ° C or the reflux temperature. The reaction time is between 30 minutes and 4 hours. These reaction conditions are not intended to be limiting. .

 The amount of solid content when the resin solution obtained as described above is used is preferably 75 or more, more preferably 85% or more. If the solids content of the resin solution after the reaction is not sufficiently high, shrink by dehydration under reduced pressure or a thin film evaporation method. In consideration of these points, it is better to use a high-permeability home-aldehyde source from the beginning. Therefore, paraformaldehyde is most preferred.

A resin solution with a high concentration as described above has a high viscosity, so that the stability of the foam at the time of foaming is better, and the foaming state is better and a uniform foam is obtained. can get . From a certain viewpoint, it is possible to find a preferable range of the viscosity of the resin. Sunawa Chi tree moon effect the viscosity of Nami 1 0, 0 0 0 ~ 4 0 0, 0 0 0 c P s 2 0 ° C, and rather are preferred, 1 0, 0 0 0-5 0 0 0 0 cps / 20 ° C. This viscosity range does not always coincide with the above-mentioned range of the resin concentration. The point is that either the resin concentration or the resin viscosity should be within the above range. The resulting resin solution has a pH of 7.5 to 8.5.

,-' Adjusted and saved. It should be noted that the above-mentioned method for producing urea resin or urine resin does not limit the purpose of the present invention, but a more preferable method for producing urea resin or urine resin. It is shown.

 In order to form a foam using the resin solution obtained as described above, a curing agent, a foaming agent, a foaming agent, etc. are uniformly mixed in the resin solution, and then the mixture is not heated to room temperature. Keep under heating. This makes it easier to get the form.

Known foaming agents are used. For example, substances that can be decomposed by acids or nausea to generate gas are used. Belong charcoal acid Na door Li cormorant-time, Jusumi Hayao Na door Li cormorant-time, to the substance of Nono ⁰ La door Norre et emissions scan le ho twenty-one Norre human de. La-di-head soil force it. It is also possible to use low-point substances such as butane, pentane, and tricyclone monophenolic ethane. Low boiling materials are more preferred. In particular, when using a trichloro mouth fluoroethane (for example, made by Asahi Glass Co., Ltd., trade name: Freon, product number: Asahi Fluorone 11), use at room temperature It is convenient because the foam can be obtained by using. The amount of the foaming agent is appropriately determined according to the required expansion ratio.

 Known foaming agents can be used, but those having a strong foaming power and a good total holding power are preferred. This includes high-alcohol sodium phosphate sodium salt, high-grade alcohol sodium salt amine salt, high-grade alcohol salt. Ano-core sodium salt, sodium salt of high-grade alcohol, high-grade alcohol salt, amin salt, high-grade alcohol salt Benzene sulphonate, dodecinoleben benzene sulphonate, phenol olenosulphate ester, alkyl naphthalene sulphonate Power is used. The luxury alcohol

c:-,- — Although it is not intended to limit the scope of the invention, the carbon number power of s' 12 to 15 phenols, ie, ci ₂ to C and _c is better. . The amount used is based on the resin solution: I to 6% is preferred

 As the curing agent, a known curing agent that is usually used as a curing agent for a urea resin is used. For example, phosphoric acid. Acidic substances such as rat enormous olenoic acid are used. The amount of the curing agent used depends on the properties of the resin and the temperature at which the resin is foamed. In the end, the appropriate amount will be determined concretely in consideration of various circumstances.

 In order to improve the compatibility between the resin solution and the foaming agent, it is recommended that the polyoxylated fatty acid ester, the sorbitan fatty acid ester, and the silicone resin be used. An activator such as a filler can be blended in an amount of 1 to 3% based on the resin solution.

In the present invention, together with the above-mentioned foaming agent and the like, a foam fixing agent for keeping the foamed resin in a foamed state until the foamed resin is completely cured is compounded. They try to get more form. For example, in the case of the conventional method, it is very difficult to control the foaming of the resin during the production of the polyurethane foam and the speed of the curing of the resin accompanying the foaming. However, if the curing speed is too fast, the foaming is sufficiently performed and the foam is cured, and a foaming force with a low expansion ratio can be formed. However, there is a drawback that the foam becomes hardened and a foam with a high expansion ratio cannot be obtained. That is, the foaming stability was bad. On the other hand, when resolsin or phenolic resin is used as a foam fixing agent, foam stability is improved. They can be used in combination. These foam fixatives It may be added to the resin solution in advance, or may be added just before foaming. In the case of resorcinol, which is a solid, if it is blended immediately before foaming, add a foam fixative as an aqueous solution with a concentration of 60 to 80% and mix it with the resin solution. Is easy. Of course advance amount of the resin solution and blended with our Ku _c foam fixing agent but it may also be added as an aqueous solution even if is against the resin liquid 0.1:! 330%, preferably 5-15%. Even in the case of phenolic furyl alcohol, the smaller the amount, the smaller the shrinkage after foaming, and a favorable result can be obtained.

 The present invention has a feature in that resorcin or phenolic free alcohol is used as a foam fixing agent, and the above-mentioned modified urea resin is used. Or by using the above-mentioned foaming agent or by using the above-mentioned foaming agent. Or the combination of the use of the above-mentioned activators to obtain even better results.

9 · .

 Without using a foam fixative, add a foaming agent and a foaming agent to the resin solution modified with e-force and multi-alcohol. Then, a foaming agent is added to the mixture to form a foam, which is not sufficient in terms of water resistance as compared with the case where the foam fixing agent is used. When you can get an effect

In particular, when polyethylene glycol is used as a denaturing agent and furfuryl alcohol is used as a foam-fixing agent,髡 You can obtain a form that is well-transformed. That is, when the foam obtained in this way touches 焰, that part is carbonized, It expands to prevent ignition and burning.

 Another effect of the use of the foaming agent is that the smoothness of the cut surface when the foam is cut is greatly reduced.

Best form to carry out the invention

 Example 1

ε-30 parts by weight of force pro- gram (abbreviated as “parts” hereinafter), 40 parts of polyethylene glycol, 40 parts of para-holon rubber (80% pure) Then, 100 parts were charged into a reaction vessel, heated and dissolved, and 4 parts of a 40% aqueous sodium hydroxide solution was added thereto, and the mixture was maintained at reflux for 30 minutes. Then, while maintaining the reaction system at 95 ° C, 200 parts of paraformaldehyde and 260 parts of urea were each divided into four parts and added alternately to the reaction system. Was. After charging all of them, the mixture was reacted at 90 to 95 for 60 minutes. The PH 5. temperature of 6 to 5. adjusted to 8 reaction system after its has Tsu coercive in 9 ⁰ ~ 9 5 0 C. When a small amount of the reaction solution was taken out and one drop was added to water 100, when the water became opaque, 28 parts of urea was added, and the pH was adjusted to 7.8 with caustic soda. After cooling, a resin solution was obtained. The viscosity of the resin liquid Ri Ah at _{1 0, 0 0 0 c P} sZ2 0 ° C, the resin solid content Tsu der 8 5%.

 Example 2

e - the force profile la Selector Selector arm 3 0 parts, Po Li et Chi les in g Li co one Norre 6 0 parts, the Nono ⁰ La e Honoré beam § Honoré de arsenide de (purity 80%) 1 0 0 part The reaction vessel was charged and heated to dissolve. Then, 4 parts of a 40% aqueous solution of caustic soda was added to the reaction system, and the mixture was kept under reflux for 30 minutes. Next, keep the temperature of the reaction system at 95 ° C. La Holmanore de Hido 200 parts and 260 parts of urea were divided into 5 parts each and added to the reaction system alternately. After adding all of them, the mixture was reacted at 90 to 95 ° C for 60 minutes, the pH of the reaction system was adjusted to 5.6 to 5.8 with formic acid, and the mixture was added. Add 40 parts of heat and temperature 90-95. C, and reacted for an additional 60 minutes. One Ide Urea 2 8 parts All good beauty high- Te Bruno - Le 3 2 5 D (Dai-ichi Kogyo Seiyaku Co., Ltd. foaming agents, synthetic § Honoré co one Norre of c _{1 2} ~ _{1 5} E preparative key sheet The sodium salt of the sodium phenol (1.5 parts) was added to the reaction system, the pH was adjusted to 7.8, and then the reaction system was cooled to obtain a resin solution. . The viscosity of the resin solution was 4,000 cp sZ 20 ° C.

 Example 3

 With respect to 100 parts of the resin solution obtained in Example 1, 8 parts of a 60 aqueous solution of resorcinol and Highenol 335 (a foaming agent manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Add 2 parts of triethanolamine salt of high-grade alcohol and 4 parts of trimethyl phosphite (flame retardant) and mix. n? 15 parts of tan were added and mixed vigorously. Next, 3 parts of phosphoric acid (85%) was added to this resin solution, and mixed vigorously. The foaming resin liquid thus obtained was cast into a mold and placed in a thermostat at 55 ° C. The foaming resin liquid in the mold 'started foaming immediately. The foam cured after about 20 minutes. The foam obtained in this way had homogeneous cells, a density of about 0.03 and a compressive strength of about 1.3 / ah. The foam exhibited self-extinguishing properties.

 Implementation 4

With respect to 100 parts of the resin liquid obtained in Example 1, the distribution shown in Table 1 was applied. A resin solution for foaming was produced in this way, and foamed at 30 ° C. in a foaming mold to obtain a foam. The quality of the foam was examined and also shown in Table 1.

> 笫

Note) T — 40 means polyoxyethylene sorbitan monomitrate.

In the above-mentioned examples, the compound containing phenolic resin and resin containing phenolic resin and resin containing resin are more effective in improving the uniformity of foaming, the expansion ratio (low density), and the strength as compared with the non-compounded product. Admitted.

 When the water resistance, odor and adhesiveness of each sample were examined, the following effects were observed.

 (a) Water resistance: As a result of immersion in water at 25 ° C for 30 days, the dimensional shrinkage of the conventional product was 7 to 8%, whereas each sample was 1.21.5. % (Meaning swelling).

 (b) Odor The generation of formal deodorant from the foamed foam and from the foamed foam was reduced.

 (c) Adhesion: Self-adhesion increased.

 In addition, when the foam obtained by blending the full-fluryl alcohol is exposed to water, a carbonized layer is formed on the foam surface and has an effect of preventing the spread of fire.

 On the other hand, the foam obtained by blending the foaming agent was smooth when cut with a blade, and the foam was not pulverized by friction.

 To 100 parts of the resin solution obtained in Example 2, the additives shown in Table 2 were added. Using the obtained foaming resin, foaming was performed at a foaming temperature of 30 ° C. to obtain a foam. Check the quality of the foam and add it to Table 2 7 ^-o

c ^ 2 ^

When any of the above samples came into contact with 焰, a charcoal layer was formed on the foam surface and fire spread was prevented. In particular, the fibrous layer expanded in 15 and showed good flame resistance.

 The foam shrank slightly after foaming, but the shrinkage was smallest for ^ 15. In this embodiment, regarding the odor of formaldehyde, compared to the case of Example 4, the odor of formaldehyde is generated at the time of foaming and from the foam. In particular, the number of samples with the combination of resorcin was the lowest. In addition, the adhesiveness was excellent for all samples. · '

c:.:? i V, no

Claims

1 7 Scope of request  (1) The method of producing urea resin foam is characterized in that resorcin or (and) furfuryl alcohol is mixed into the urea resin liquid. A method for producing urea resin foam.  (2) In the process for producing urea resin foam, urea resin or (and) phenolic alcohol is added to the urea resin solution. A method for producing urea resin foam, which is characterized by blending different foaming agents.  (3) It is characterized that the amount of resin or (and) phenol is 0.1 to 30% by weight of the resin liquid. The method of claim 1 or 2.  (4) As the urea resin liquid, a resin liquid modified with an e-force program or (and) a polyhydric alcohol is used. The manufacturing method of Claims 1 or 3. (5) foaming agent, Ru Oh in C i 2 ~ C i ₅ of luxury A Le co-Lumpur E door key shea monkey off We one door of Na door Li ©-time Shioma other § Mi emissions salt The manufacturing method according to claim 2, which is characterized by this. (6) It is characterized in that the foaming agent is a sodium salt or a salt of a salt of high-grade alcohol of Ci 2 to C, _5. The manufacturing method according to claim 2.  (7) The method according to any one of claims 1 to 5, wherein a urea resin solution having a solid content of 70% by weight or more is used.