JPH10168147A - Low-viscosity aromatic hydrocarbon formaldehyde resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin, producible without any reduction in resin yield, capable of manifesting a low viscosity and a low pour point and useful as a raw material for reaction and a plasticizer, etc., by the presence of a specific alcohol in a specific proportion at the time of condensation reaction of an aromatic hydrocarbon with formaldehyde. SOLUTION: This low-viscosity aromatic hydrocarbon formaldehyde resin is obtained by carrying out the condensation reaction of (A) an aromatic hydrocarbon with (B) formaldehyde and (C) a 1-8C aliphatic alcohol in the presence of (D) an acidic catalyst and prepared so as to provide 5-18wt.% oxygen atom concentration in the resin and 20-15,000cP viscosity at 25 deg.C. The resin is obtained by charging, e.g. the components A, B and C at a ratio so as to afford 1:(0.5-5) molar ratio of the components A:B and 1:(0.2-1) molar ratio of the components B:C and conducting the condensation reaction in the presence of the component D at 80-100 deg.C temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-viscosity aromatic hydrocarbon formaldehyde resin containing a certain percentage of oxygen atoms in the resin and a method for producing the same.

[0002]

2. Description of the Related Art It is known to produce an aromatic hydrocarbon formaldehyde resin by reacting an aromatic hydrocarbon with formaldehyde in the presence of an acid catalyst, and in particular, a resin obtained by reacting meta-xylene with formaldehyde in the presence of a sulfuric acid catalyst. Is well known as a xylene formaldehyde resin. This xylene formaldehyde resin is modified with phenols, carboxylic acids, glycols, etc. and used for various applications as a thermosetting resin material, used as a tackifier such as an adhesive and a pressure-sensitive adhesive, and further used as an epoxy resin. It is well known that it is used as a diluent or a plasticizer for vinyl chloride resin.

However, when the aromatic hydrocarbon formaldehyde resin is used as an epoxy resin diluent or a plasticizer such as vinyl chloride, it contributes to excellent properties such as water resistance, chemical resistance, and electrical properties. It has practical disadvantages such as too high viscosity itself and high pour point.
In addition, the fact is that the viscosity is too high for a solventless epoxy resin, a diluent for a urethane resin, and the like, so that it is practically difficult to use them.

In order to reduce the viscosity of an aromatic hydrocarbon formaldehyde resin, 3 to 8 moles of an aromatic hydrocarbon are used per 1 mole of formaldehyde as in the method described in JP-A-60-51133. There is a method of producing a polybenzyl-type oligomer by using an acid catalyst such as paratoluenesulfonic acid. The resin obtained by this method has a viscosity of 50 centipoise (25 ° C.)
Although the degree is low, the obtained resin does not substantially contain oxygen atoms, has no reactivity with phenols, carboxylic acids, and glycols, and has poor compatibility with epoxy resins and urethane resins. There is. Further, in order to lower the viscosity of the aromatic hydrocarbon formaldehyde resin, there is a method in which the reaction is stopped at a low reaction rate and the condensation is not advanced much, but this method is not preferable because the resin yield is low.

[0005]

The present invention does not have the above-mentioned disadvantages found in conventional aromatic hydrocarbon formaldehyde resins, and is suitable as a raw material for reaction and for various uses such as plasticizers and diluents. It is an object of the present invention to provide an aromatic hydrocarbon formaldehyde resin having a low viscosity and a low pour point, which can be used as an additive for a solventless paint, and a method for producing the same.

[0006]

Means for Solving the Problems As a result of diligent studies, the present inventors have found that the above-mentioned problems can be solved when a certain ratio of aliphatic alcohol having 1 to 8 carbon atoms is present in the condensation reaction between aromatic hydrocarbon and formaldehyde. Find out what can be solved,
The present invention has been completed.

That is, the present invention relates to (1) a low-viscosity aromatic hydrocarbon formaldehyde resin obtained by subjecting an aromatic hydrocarbon, formaldehyde, and an aliphatic alcohol having 1 to 8 carbon atoms to a condensation reaction in the presence of an acidic catalyst. A low-viscosity aromatic hydrocarbon formaldehyde resin having an oxygen atom concentration in the resin of 5 to 18% by weight and a viscosity of 20 to 15,000 centipoise (25 ° C.), and (2) an aromatic hydrocarbon and formaldehyde And a condensation reaction in the presence of an acidic catalyst to obtain an aromatic hydrocarbon formaldehyde resin, wherein 0.3 to 0.7 mol of an aliphatic alcohol having 1 to 8 carbon atoms is present per 1 mol of formaldehyde. The invention relates to a method for producing a low-viscosity aromatic hydrocarbon formaldehyde resin, characterized by the following.

The aromatic hydrocarbons used in the present invention include three isomers of toluene, ethylbenzene and xylene, mesitylene, pseudocumene, monocyclic aromatic hydrocarbon compounds having 10 or more carbon atoms, naphthalene, methylnaphthalene and the like. And polycyclic aromatic hydrocarbon compounds.
In addition, these mixtures can also be used.

Examples of the formaldehyde include compounds that generate formaldehyde such as formalin, paraformaldehyde, and trioxane, which are industrially easily available. In the present invention, even if a polymer such as paraformaldehyde or trioxane is used, the blending amount is defined based on one molecule of formaldehyde.

The alcohol used in the present invention acts as a terminal terminator for the aromatic hydrocarbon formaldehyde resin, and therefore may be any aliphatic alcohol, and practically an aliphatic alcohol having 1 to 8 carbon atoms can be used. , Having 1 to 1 carbon atoms
Four aliphatic alcohols are particularly desirable. As aliphatic alcohols having 1 to 8 carbon atoms, methanol, ethanol,
n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol, pentanol (including each isomer), heptanol (including each isomer), 2-ethyl-hexyl alcohol, n-octanol, etc. Can be exemplified.

In the present invention, by using an aliphatic alcohol having 1 to 8 carbon atoms, the yield of a low-viscosity aromatic hydrocarbon formaldehyde resin obtained by the reaction can be improved.

As the catalyst used in the condensation reaction, sulfuric acid, paratoluenesulfonic acid and the like can be mentioned. In general, sulfuric acid is suitable, and the amount used is diluted with the water in the aqueous formaldehyde solution. 10-5 as concentration
It is desirable to adjust to be 0% by weight. When the concentration of sulfuric acid is less than the above 10% by weight, the rate of the reaction becomes extremely slow, which is not practical. If it exceeds 50% by weight, the reaction speed is high and the viscosity of the resin is undesirably high.

The molar ratio of the aromatic hydrocarbon and formaldehyde used in the condensation reaction is 1: 0.5 to 5, preferably 1: 1 to 3. The charged molar ratio is 0.
If it is less than 5, the oxygen content in the obtained aromatic hydrocarbon formaldehyde resin will decrease, and if it exceeds 3, the unreacted formaldehyde will increase, which is not preferable.

The charge molar ratio of formaldehyde to alcohol at the time of the condensation reaction is in the range of 1: 0.2 to 1, preferably 1: 0.3 to 0.7. When the charged molar ratio is less than 0.2, the effect of diluting the viscosity is small, and when it is more than 1, alcohols remain unreacted, which is not preferable.

The reaction temperature is a temperature at which aromatic hydrocarbons, alcohols, water, formalin, and formal (produced from alcohol and formalin in the reaction system) existing in the reaction system are refluxed, and usually about 80 to 100 ° C. The reaction time is usually about 2 to 6 hours.

By adding an aliphatic alcohol such as methanol to a system in which an aromatic hydrocarbon and formaldehyde are heated and reacted in the presence of a sulfuric acid catalyst under the above conditions to synthesize a resin, the added alcohol becomes xylene and mesitylene. It may be incorporated as an alkoxy group at the terminal of the formaldehyde resin molecule to lower the molecular weight, lowering the viscosity and still containing an oxygen atom in the molecule.

The viscosity of the aromatic hydrocarbon formaldehyde resin obtained in the present invention is 20 to 15,000 centipoise (25 ° C.), preferably 30 to 5000 centipoise (25 ° C.). The viscosity of the aromatic hydrocarbon formaldehyde resin can be controlled to 20 to 15,000 centipoise (25 ° C.) by the mixing ratio of the aromatic hydrocarbon, formaldehyde, and aliphatic alcohol having 1 to 8 carbons used. Is 20 centipoise (25
C.), the loss on heating increases, and if it exceeds 15,000 centipoise (25.degree. C.), the dilution effect when used in combination with various resins is reduced, which is not preferable.

The oxygen atom concentration in the obtained aromatic hydrocarbon formaldehyde resin is 5 to 18% by weight, preferably 8 to 16% by weight. Oxygen atom concentration in the aromatic hydrocarbon formaldehyde resin, the aromatic hydrocarbon used,
It can be controlled to 5 to 18% by weight by adjusting the mixing ratio of formaldehyde and an aliphatic alcohol having 1 to 8 carbon atoms. If the oxygen atom concentration is less than 5% by weight, the phase with epoxy resin, urethane resin, etc. The solubility is reduced, and
Exceeding the weight percent results in poor compatibility with the acrylic resin, which is not preferred.

The resin thus obtained has a low viscosity and reactivity with phenols, carboxylic acids, glycols and the like having active hydrogen, and is compatible with epoxy resins, urethane resins and their hardeners. Good solubility. Further, the resin is suitable for various uses such as a plasticizer and a diluent, and is particularly suitable as an additive for a solventless paint.

[0020]

EXAMPLES Examples and comparative examples are shown below to explain the present invention in detail. In Examples and Comparative Examples, “%” and “parts” indicate “% by weight” and “parts by weight”, respectively, unless otherwise specified.

Example 1 A 2-liter separable flask equipped with a thermometer, a reflux condenser and a stirrer was charged with 240 parts of 50% formalin, 55 parts of methanol, 101 parts of 98% industrial sulfuric acid, and 212 parts of meta-xylene. Charge and react at reflux temperature of 84 to 88 ° C for 4 hours. After completion of the reaction, the mixture was allowed to stand to separate a resin phase and a sulfuric acid aqueous phase.
g / 120-130 ° C. for 20 minutes by stripping unreacted meta-xylene to give a viscosity of 50 centipoise (25
C.) of xylene formaldehyde resin.
The pour point of the obtained resin is 0 ° C. or less, and the oxygen content is 13 ° C.
%Met.

Examples 2 to 8 In the same manner as described in Example 1, metaxylene or mesitylene was used as the aromatic hydrocarbon, and methanol, ethanol, iso-propanol, n-butanol or 2-ethyl-hexyl was used as the alcohol. Using alcohol, an aromatic hydrocarbon formaldehyde resin was obtained. Tables 1 and 2 show the mixing ratio of the raw materials charged and the physical properties of the resin obtained by the reaction.

Comparative Example 1 A xylene formaldehyde resin was obtained in the same manner as in Example 1 except that no alcohol was added.
Table 2 shows the mixing ratio of the raw materials charged and the physical properties of the resin obtained by the reaction.

[0024]

The low-viscosity aromatic hydrocarbon formaldehyde resin obtained in the present invention is also effective as a modifier with a compound having active hydrogen such as phenol, carboxylic acid, and glycol. It is also very effective as a diluent for solvent-based epoxy resins and urethane resins.

[0025]

[Table 1] Example No. 2 3 4 5 6 Preparation (parts) 50% Formalin 240 240 240 240 240 98% Sulfuric acid 90 68 60 79 100 Metaxylene 212--212 212 Mesitylene-240 240--Methanol 23 62 26- -Ethanol---79- iso-propanol ----43 Charge molar ratio HCHO ^{* 1} / HC ^{* 2} 2.0 2.0 2.0 2.0 2.0 ROH ^{* 3} / HCHO ^{* 1} 0.36 0.97 0.41 0.86 0.36 Reaction temperature (℃) 89-96 83-88 90-96 85-88 85-88 Reaction time (h) 4 4 4 4 4 Resin yield (parts) 280 290 320 250 295 Viscosity (cP / 25 ° C) 1200 50 4900 50 1000 Oxygen content (%) 12 15 11 12 11 Pour point (° C) 0>0>0>0>0> Abbreviation * 1: Formaldehyde * 2: Aromatic hydrocarbon used * 3: Alcohol used

[0026]

[Table 2] Examples and Comparative Examples No. 7 7 8 1 ratio (parts) 50% formalin 240 240 240 98% sulfuric acid 78 76 80 meta-xylene--212 mesitylene 240 240-n-butanol 100-- C8 alcohol ^{* 4} - 106 - molar ratio ^{HCHO * 1 / HC * 2 2.0} 2.0 2.0 ROH * 3 / HCHO * 1 0.67 0.41 - reaction temperature (℃) 85~90 90~96 95~105 reaction time (h) 4 4 4 resin Yield (parts) 310 320 280 Viscosity (cP / 25 ° C) 50 2000 2000000 Oxygen content (%) 14 9 9 Pour point (° C) 0>0> -Abbreviation * 1: Formaldehyde * 2: Aromatic hydrocarbon used * 3: Alcohol used * 4: 2-ethyl-hexyl alcohol

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kita Seiji 3-10-10 Mizushima Kaigandori, Kurashiki-shi, Okayama Prefecture Inside Mizushima Plant, Mitsui Gas Chemical Co., Ltd. 10 Mizushima Chemical Co., Ltd. Mizushima Plant (72) Inventor Kazuhito Kishimoto 3-10 Mizushima Kaigandori, Kurashiki City, Okayama Prefecture Mizushima Gas Chemical Co., Ltd. Mizushima Plant

Claims (9)

[Claims] 1. A low-viscosity aromatic hydrocarbon formaldehyde resin obtained by subjecting an aromatic hydrocarbon, formaldehyde, and an aliphatic alcohol having 1 to 8 carbon atoms to a condensation reaction in the presence of an acidic catalyst. Oxygen atom concentration is 5
A low-viscosity aromatic hydrocarbon formaldehyde resin which is 18% by weight and has a viscosity of 20 to 15,000 centipoise (25 ° C.). 2. The low-viscosity aromatic hydrocarbon formaldehyde resin according to claim 1, wherein the aromatic hydrocarbon used is at least one of xylene and mesitylene. 3. The method according to claim 1, wherein the acidic catalyst used is sulfuric acid.
5. The low-viscosity aromatic hydrocarbon formaldehyde resin described in 1. 4. The low-viscosity aromatic hydrocarbon according to claim 1, wherein the blending ratio (molar ratio) of the aromatic hydrocarbon and formaldehyde used is 1: 0.5 to 5.0. Formaldehyde resin. 5. The formaldehyde used and the number of carbon atoms of 1 to 5
The mixing ratio (molar ratio) of the aliphatic alcohol of No. 8 is 1:
The low-viscosity aromatic hydrocarbon formaldehyde resin according to any one of claims 1 to 3, which is 0.2 to 1. 6. The alcohol used is at least one selected from aliphatic alcohols having 1 to 4 carbon atoms.
5. The low-viscosity aromatic hydrocarbon formaldehyde resin according to any one of items 1 to 4. 7. The low-viscosity aromatic hydrocarbon formaldehyde resin according to claim 1, wherein the resin has an oxygen atom concentration of 8 to 16% by weight. 8. A liquid having a viscosity of 30 to 5000 centipoise (2
5. The low-viscosity aromatic hydrocarbon formaldehyde resin according to any one of claims 1 to 4, which has a temperature of 5 ° C. 9. When an aromatic hydrocarbon and formaldehyde are subjected to a condensation reaction in the presence of an acidic catalyst to obtain an aromatic hydrocarbon formaldehyde resin, an aliphatic alcohol having 1 to 8 carbon atoms is added to 1 mole of formaldehyde. , 0.2-
A method for producing a low-viscosity aromatic hydrocarbon formaldehyde resin, characterized in that one mole is present.