JPS60123519A - Production of cured article of odorless or low odor crosslinking compound - Google Patents

Abstract

PURPOSE:An odorless or low odor crosslinking compound, obtained by reacting an aromatic hydrocarbon with formaldehyde and an alpha,beta-unsaturated monocarboxylic acid, curable by itself, and having improved copolymerizability with polyesters, etc. and electrical characteristics at high temperatures. CONSTITUTION:(A) One mol aromatic hydrocarbon, e.g. m-xylene or toluene, is reacted with (B) 1-50mol formaldehyde, e.g. paraformaldehyde, alpha-polyoxymethylene or 37.5wt% aqueous solution of formula, and (C) 1-50mol alpha,beta-unsaturated carboxylic acid, e.g. methacrylic acid or acrylic acid within 80-180 deg.C reaction temperature range and within 5-30hr reaction time range.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an odorless or low-odor cured product of a crosslinkable compound, and more specifically, to a method for producing an odorless or low-odor cured product obtained by reacting an aromatic hydrocarbon, formaldehyde, and an unsaturated monocarboxylic acid. The present invention relates to a method for producing a cured product of a crosslinkable compound.

Unsaturated polyester resins have excellent workability and properties after curing, and are inexpensive, so they are used in large quantities. This unsaturated polyester resin usually contains 40 to 60% by weight of styrene monomer as a crosslinkable monomer, and 10 to 30% by weight of the styrene monomer based on the total amount of the resin is volatilized and lost during the heat curing process. However, this styrene material,
Il! ! % of pungent odor and is harmful, it has come to be legally regulated under the Offensive Odor Prevention Law or local ordinances. For example, Osaka Prefectural Ordinance defines styrene as a harmful gas, and its concentration must be below 1 pI)m at the property line.

Furthermore, the Tokyo Metropolitan Ordinance stipulates that the discharge outlet standard is 501) pm or less. As laws and regulations have become stricter, there has been an urgent need to reduce the odor and volatility of unsaturated polyester resins, both from the standpoint of working environments and resource conservation.

In response to this situation, manufacturers are developing and commercializing various low-odor unsaturated polyester resins. Their feature is that they all use diallyl phthalate instead of styrene as a monomer. However, when this is used as a monomer, there are problems such as poor copolymerizability with polyester, poor electrical properties at high temperatures, and high cost.

The present invention was made in view of the above circumstances, and its purpose is to provide a method for producing a cured product with excellent electrical properties at high temperatures using an odorless or low-odor crosslinking compound. .

In order to achieve the above object, the present inventors conducted various studies and found that aromatic hydrocarbons, formaldehyde and Cχ
The crosslinkable compound obtained by the reaction of β-unsaturated monocarboxylic acid cures itself.

Furthermore, they found that it has good copolymerizability with polyester and the like, and that the cured product thereof has good electrical properties at high temperatures and is odorless to low odor, leading to the completion of the present invention.

That is, the present invention relates to a method for producing a cured product by curing an odorless to low odor crosslinkable compound obtained by reacting an aromatic hydrocarbon, formaldehyde, and an α,β-unsaturated monocarboxylic acid.

Examples of aromatic hydrocarbons used as raw material components in the present invention include 9m-xylene and toluene.

Examples include mesitylene, teyulene, and naphthalene.

Further, representative examples of α,β-unsaturated monocarboxylic acids include methacrylic acid and acrylic acid. Further, examples of formaldehyde include paraformaldehyde, α-polyoxymethylene, and a 37.5 weight cup of formalin aqueous solution.

The above aromatic hydrocarbons, formaldehyde and α.

The reaction of the β-unsaturated monocarboxylic acid is carried out under heating while blowing air, using an acidic catalyst and a polymerization inhibitor if necessary. During the reaction, the viscosity of the crosslinkable compound as a product and the amount of unsaturated monocarboxymethyl groups introduced can be arbitrarily adjusted by varying the type and blending ratio of raw materials, the amount of acidic catalyst, the reaction temperature, and the reaction time. It is possible to obtain a crosslinking compound suitable for each application.

Formaldehyde 1 to 1 mole of aromatic hydrocarbon
It is preferable to use the α, β-unsaturated monocarboxylic acid in an amount of 1 to 50 mol.・Reaction temperature is 80-1
The reaction time at 50°C is preferably in the range of 5 to 30 hours. Further, N-methylpyrrolidone, dimethylsulfoxide, benzene, etc. may be used as a solvent.

Examples of acidic catalysts used as necessary in the reaction include sulfuric acid, perchloric acid, phosphoric acid, acetyl perchloric acid,
Trifluoromethanesulfonic acid.

polylyte/acid, chlorosulfonic acid,) luenesulfonic acid,
Examples include xylene sulfonic acid, poly(styrene sulfonic acid) resin, silica gel, and phosphoric acid supported on activated carbon.

The obtained crosslinkable compound is confirmed to have an α,β-unsaturated monocarboxymethyl group by its infrared absorption spectrum and nuclear magnetic resonance absorption spectrum. This compound has the feature of being odorless or having low odor. Moreover, it can undergo radical polymerization at low temperatures, forms a cured product by itself, and the obtained cured product has excellent electrical properties at high temperatures.

Curing temperature is from room temperature to 200°C, preferably from room temperature to 1
Curing time at 50°C is 10 minutes to 50 hours, preferably 1 to 15 hours.
It is considered to be a time range. During curing, a curing agent described below and, if necessary, a curing accelerator described below are used.

Furthermore, this crosslinkable compound is an unsaturated polyester.

It can also be used as a crosslinking agent for acrylic acid- or methacrylic acid-modified polybutadiene resins, and the resulting cured product has better electrical properties at high temperatures than when conventional crosslinkable monomers are used.

Examples of the unsaturated polyester crosslinked with the crosslinkable compound of the present invention include the following alcohol components.

Examples include various general-purpose unsaturated polyesters obtained from an acid component and a modifier (optional component).

(1) Alcohol component Ethylene glycol, propylene glycol.

Diethylene glycol, dipropylene glycol.

triethylene glycol, 1,3-furopanediol,
1,2-propanediol, 1,2-phthanediol,
1,3-butanediol, 1,4-butanediol, 1
．． 2-bentanediol, 1,3-bentanediol,
Aliphatic glycols such as 1,2-hexanediol, 1,4-hexanediol, 2,3-hexanediol, dipropylene glycol; cycloaliphatic diols such as cyclopencune diol, cyclohexanediol; xylene glycol, dimethylxylene glycol , 212-bis(4-hydroxyphenyl)propane and other aromatic diols; bisethylene glycol ether, bisethylene glycol ether, bisbutylene glycol ether and other ethers; glycerin, trimethylolethane, trimethylolpropane, pentaerythritol any polyhydric alcohol; or a mixture thereof. The above-mentioned alcohols are generally produced industrially and used in the production of unsaturated polyesters.

(2) Acid component - rL' inic acid I hydromaleic acid, fumaric acid, itaconic acid, citraconic acid, endomethylenetetrahydrophthalic anhydride, tetrahydrophthalic anhydride.

Unsaturated carboxylic acids such as methyltetrahydrophthalic anhydride, linseed oil, soybean oil, tall oil, and coconut oil.

Vegetable oils such as castor oil fatty acids, derivatives thereof or mixtures thereof. If necessary, saturated acids such as phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, etc. can be used together with the above components.

(3) Modifier (optional component) Cyclopentadiene, dicyclopentadiene, etc. are used.

The acrylic acid- or methacrylic acid-modified polybutadiene resin that is crosslinked with the crosslinkable compound produced by the present invention is a resin in which an active group is introduced at the end of polybutadiene, and this active group is reacted with a carboxyl group of acrylic acid or methacrylic acid. can be obtained. A resin having a reactive double bond at the end.

For example, TE-2000 (methacrylic acid modified polybutadiene resin 1 manufactured by Nippon Soda), VTB2000X164°V
TBN1300X22. Examples include VTBNX1300X23 (acrylic acid-modified polybutadiene resin, manufactured by Ube Industries, Ltd.).

aromatic hydrocarbon, formaldehyde, and α to 100 parts by weight of unsaturated polyester or acrylic acid- or methacrylic acid-modified polybutadiene resin.

It is preferable to use 20 to 500 parts by weight of a crosslinkable compound obtained by reacting with a β-unsaturated monocarboxylic acid.

The resulting odorless or low-odor resin composition may contain, in addition to the above-mentioned essential components, a curing agent, a curing accelerator, a crosslinkable monomer 9 polymerization inhibitor, a filler, and the like.

As curing agents, acyl peroxides such as benzoyl peroxide and acetyl peroxide; hydroperoxides such as tert-butyl peroxide and cumene hydroperoxide; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; di-tert-butyl peroxide; oxide.

Dialkyl(-oxide; tertiary-butyl perbenzoate, such as dicumyl peroxide).

Oxyperoxides such as tert-butyl peroxyacetate can be used. The amount used generally ranges from 0.5 to 5% by weight, preferably from 1 to 3% by weight, based on the resin composition.

As a curing accelerator, commonly used metal salts of naphthenic acid or octenoic acid (for example, cobalt, manganese, iron, lead, nickel, tin, zinc salts, etc.) can be used.
The amount added is in the range of 0 to 2.0% by weight based on the resin composition.

Examples of crosslinking monomers include styrene and various high-boiling acrylic esters or methacrylic esters.

High-boiling point allyl ethers or allyl esters are used as necessary. For example, allyl ethers such as trimethylolpropane triallyether, glycerin triallyl ether, diallyl phthalate, diallyl inphthalate, triallyl isocyanurate, triallyl cyanurate, etc. Allyl esters such as nurate are used.

Hydroquinone and paratertiary polymerization inhibitors
Quinones such as butylcatechol and pyrogallol, and other commonly used quinones can be used. The amount added is 0 to 0.5% by weight relative to the resin composition.

As the filler, silica, talc, calcium carbonate, asbestos, glass fiber, wood powder, coloring agent, etc. added to the polyester resin are used as necessary.

The present invention will be further explained below with reference to Examples, but the present invention is not limited to these Examples.

Reference Example 1 L equipped with an air introduction pipe, thermometer, reflux condenser and stirrer
1 m-xylene 2129 (2.0 mol), paraformaldehyde (Wako Tsumugi reagent grade) in a four-eye flask.
180 g (6.0 mol calculated as HCH'0), methacrylic acid 3449 (4.0 mol).

t-butylcatechol o, 5g and 60% perchloric acid 20
9 was added, and the mixture was vigorously stirred at 100° C. for 8 hours while blowing air. The reaction product was washed with water, then with an aqueous solution of about 10 parts by weight of sodium carbonate, and then with water. The organic layer was dehydrated to obtain a crosslinkable compound (Al) with 3 poise at room temperature. This compound (Al) was almost odorless. When the infrared absorption spectrum of this substance (Al was measured), 1
A strong absorption based on the carbonyl group of the methacryloylmethyl group was observed at 720 cm-1. Also, this substance (A
), the nuclear magnetic resonance spectra of δ-5,
A strong absorption based on methylene of the methacryloylmethyl group was observed at 10 pI)m, and it was found that 0.8 mol of methacryloylmethyl group was present per 1 mol of xylene nucleus.

Reference example 2 3 equipped with an air introduction pipe, thermometer, reflux condenser and stirrer
In-xylene 2129 (2
,0 mol), halaformaldehyde 1809 (HCH
6.0 mol (calculated as O), methacrylic acid 17209 (20 mol), t-butylcatechol 1.0 g, and concentrated sulfuric acid 209
was added and stirred vigorously under reflux for 8 hours while blowing air. Next, after distilling off unreacted methacrylic acid, the solution was repeatedly washed with warm water until it became neutral. moreover.

After dehydration, an almost odorless crosslinkable compound (B) was obtained.

This compound (Bl) was a 6 poise liquid at room temperature.

Furthermore, when the nuclear magnetic resonance spectrum of this substance CB+ was measured, a strong absorption based on the methylene of the methacryloylmethyl group was observed at δ=5.1Or)I)m, and 1 methacryloylmethyl group was present for 1 mole of xylene nucleus. It was found that there were .3 moles.

Reference example 3 37.5% by weight of paraformaldehyde in formalin 4
The reaction was carried out under the same conditions as in Example 1, except that the amount was changed to 80 g, and an almost odorless crosslinkable compound (C) was obtained. When the nuclear magnetic resonance spectrum of this compound (C) was measured, δ
-5,1101) A strong absorption based on methylene of the methacryloylmethyl group was observed in I).

0 methacryloylmethyl group per mole of xylene nucleus
．． It was found that there were 7 moles.

Reference Example 4 A reaction was carried out under the same conditions as in Example 1, except that paraformaldehyde was changed to α-polyoxymethylene manufactured by Sumitomo Bakelite, and an almost odorless crosslinkable compound (D) was obtained. When the nuclear magnetic resonance spectrum of this compound CD+ was measured, strong absorption based on the methylene of the methacryloylmethyl group was observed at δ = 5.1 (H)I)m, and the xylene nucleus 1
It was found that 0.7 moles of methacryloylmethyl group were present per mole.

Reference example 5 60 g (2 mol) of paraformaldehyde fil
The reaction was carried out under the same conditions as in Example 1, except that
An almost odorless crosslinkable compound (E) was obtained. This compound (E
) was measured by its nuclear magnetic resonance spectrum.

A strong absorption based on methylene of the methacryloylmethyl group was observed at δ=5.10I)I)m, and it was found that 04 moles of the methacryloylmethyl group were present per mole of xylene nucleus.

Reference Example 6 The reaction was carried out under the same conditions as in Example 2, except that the amount of paraformaldehyde was changed to 6009 (2 mol), and an almost odorless crosslinking compound (Fl was obtained. This compound tI")
When we measured the nuclear magnetic resonance spectrum of δ-5,1
In 101) I), strong absorption based on methylene of the methacryloylmethyl group was observed, and it was found that 1.0 mol of methacryloylmethyl group was present per 1 mol of xylene nucleus.

Reference Example 7 A reaction was carried out under the same conditions as in Example 1 except that m-xylene was changed to 184 g (2.0 mol) of toluene to obtain an almost odorless crosslinking compound (Gl). Measurement of infrared absorption spectrum.

A strong absorption based on the carbonyl of the methacryloylmethyl group was observed at 1720C[I+-'. In addition, when nuclear magnetic resonance spectrum was measured, δ-5,1101)I)
A strong absorption based on was observed, and it was found that 08 moles of methacryloylmethyl group existed per 1 mole of toluene nucleus.

Reference Example 8 A reaction was carried out under the same conditions as in Example 1, except that 288 g (4.0 mol) of acrylic acid was used instead of methacrylic acid, to obtain an almost odorless crosslinkable compound Cl-1. The infrared absorption spectrum of this compound (group) was measured.

A strong absorption based on the carbonyl of the acroylmethyl group was observed at 1720 cm. Further, when a nuclear magnetic resonance spectrum was measured, strong absorption based on δ-5,101) pm was observed, and it was found that 0.8 mol of acryloylmethyl group was present per 1 mol of xylene nucleus.

Example 1 Crosslinkable compounds (A) to (Hl) obtained in Reference Examples 1 to 8 were mixed with 0.5 weight percent of P'll'-28 (cobalt naphthenate solution 1 manufactured by Hitachi Chemical Co., Ltd.) and CT-7 (Tertiary
Butyl perbenzoate (manufactured by Hitachi Chemical) 1.0
Parts by weight were added, and the mixture was kept at 120° C. for 5 hours to cure. Table 1 shows the state of the varnish and the properties of the cured product.

(Note 1)...The odor was determined in the varnish state, and the odor during drying was determined using an SA type standard dryer (450 x 35
0x350mm) at 130°C, and in this set a tin container (100x100x20m) containing 30g of each varnish.
m) was placed in the dryer, and the odor inside the dryer was determined 30 minutes later.

(Note 2)...10 varnish on a 60mmφ metal petri dish
g was placed in the container and kept at 120° C. for 3 hours, and the weight loss rate was measured.

(Note 3)... Measured using a BL type rotational viscometer.

(Note 4)...18mm 1φ test tube with a height of 70mm
The gelation time was measured using a varnish and a GE gel timer.

(Note 5)...The bending properties of a 5 x 10 x 100 mm resin plate were measured using a Tensilon type universal testing machine at a speed of 3 mm/min and a span of 80 man for two songs.

(Note 6) = A resin plate of 2 x 100 x 100 mm was coated with silver paint, and measured using a T-2100 automatic phase characteristic measuring machine manufactured by Ando Electric KL.

As is clear from Table 1, the crosslinkable compound (A).

(B), (C), (DJ, (El, (F),
It was found that (G) and (H) have low odor to no odor in the varnish state and when drying, and the amount of volatilization when maintained at 120° C. for 3 hours was as low as 2.8 to 4.4 weight ratio. Furthermore,
It was also confirmed that the electrical properties at high temperatures were also good.

As described above, the present invention provides a cured product with excellent electrical properties at high temperatures using an odorless or low-odor crosslinkable compound that satisfies the requirements for pollution prevention and resource conservation.

Claims (1)

[Claims] 1. aromatic hydrocarbon, formaldehyde and α. A method for producing a cured product, which comprises curing an odorless or low-odor crosslinkable compound obtained by reacting a β-unsaturated monocarboxylic acid. 2. The method for producing a cured product according to claim 1, wherein the aromatic hydrocarbon is m-xylene or toluene. 3. Formaldehyde is paraformaldehyde, α
- The method for producing a cured product according to claim 1 or 2, which is polyoxymethylene or a 37.5% by weight aqueous polymerine solution. 4. Claim 1, wherein the α,β-unsaturated monocarboxylic acid is methacrylic acid or acrylic acid. A method for producing a cured product according to ratio 2 or 3.