JPH0721015B2 - Curable resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has an α, β-unsaturated carboxylic acid anhydride-vinyl compound copolymer as a basic skeleton, and has an α, β-unsaturated carboxylic acid skeleton side group. The present invention relates to a novel curable resin whose chain is a mixture of a carboxyl group, an unsaturated alcohol ester group and a saturated alcohol ester group.

More specifically, it relates to a novel curable resin having an excellent balance of acid value and curability.

[Prior Art] A curable resin of a type having a carbon-carbon double bond in a side chain is compared with a curable resin such as an unsaturated polyester resin having a carbon-carbon double bond and an ester bond in a main chain. Since it has excellent properties in terms of physical properties, its use is expanding in various fields.

The above compound is produced by reacting a compound having a carbon-carbon double bond in its side chain with the main chain of another compound having no carbon-carbon double bond in its side chain.

For example, α, β-unsaturated acid anhydride, the vinyl anhydride compound is polymerized with an acid anhydride group of allyl alcohol,
With an unsaturated alcohol such as 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate,
By reacting an esterified compound and its free carboxyl group with an unsaturated epoxy compound such as allyl glycidyl ether, glycidyl methacrylate or glycidyl acrylate, the side chain is carbon-carbon 2
A resin having a heavy bond can be produced.

An example of such a compound is one having the following structure.

(However, R is a compound residue not having an active double bond such as an alkyl group or a benzene nucleus, and R'is a compound residue having a double bond such as an allyl group) [Problems to be Solved by the Invention] However, compounds obtained by esterifying the acid anhydride group of the α, β unsaturated carboxylic acid anhydride-vinyl compound copolymer with an unsaturated alcohol such as allyl alcohol, 2-hydroxyethyl methacrylate, and 2-hydroxyethyl acrylate are , The free carboxyl group remains, so the acid value is high.

In the meantime, when a compound having a double bond such as allyl alcohol is used to block most of the carboxyl groups by esterification (that is, when R'in the above formula is larger than the carboxyl groups), the acid value is Can be reduced, but the curability becomes excessive.

On the other hand, when a compound having no double bond is used to block most of the carboxyl groups by esterification, oxidation can be reduced, but curability is not imparted.

That is, the means as described above cannot control the balance between the acid value and the curability.

If used with a high acid value, it is difficult to dissolve in a solvent such as propylene glycol acetate, and when used in the step of reacting a free carboxyl group with an unsaturated epoxy compound such as glycidyl (meth) acrylate, it becomes an epoxy compound. The reaction rate of the resin becomes high, causing gelation of the resin,
An unmoldable mass forms.

Conversely, if the amount of double bonds is insufficient, the curability will be insufficient.

Further, if the reaction rate of the unsaturated epoxy compound is suppressed in order to prevent the gelation of the resin, the reaction rate of the free carboxyl group will not be sufficiently increased, so that a resin with good performance cannot be obtained.

On the other hand, all of the unbalanced resins have inherent tackiness as described above, and there are various problems such as stickiness in work and decrease in work efficiency, and that they are too hard and difficult to mold. ing.

In any case, the use will be limited.

Therefore, the present inventors have found a novel resin having a structure in which the acid value and the amount of double bonds can be freely changed, and completed the present invention.

[Structure of the Invention] That is, the present invention has a "α, β-unsaturated carboxylic acid anhydride-vinyl compound copolymer as a basic skeleton, and a side chain in the α, β-unsaturated carboxylic acid skeleton is (a) a carboxyl group. (B) unsaturated alcohol ester group (c) curable resin which is a mixture of saturated alcohol ester groups.

The present invention will be described in detail below.

Α, β-used for producing the α, β-unsaturated carboxylic acid anhydride-vinyl compound copolymer in the present invention
Examples of unsaturated carboxylic acid anhydrides include maleic anhydride, citraconic anhydride, 2-ethylmaleic anhydride, 2-phenylmaleic anhydride, and 2-chloromaleic anhydride.

As the vinyl compound to be copolymerized with the α, β-unsaturated carboxylic acid anhydride, any vinyl compound can be used as long as it can be copolymerized with the α, β-unsaturated carboxylic acid anhydride, and two or more kinds can be used in combination. Good.

As typical examples of such vinyl compounds, for example, styrene, 2-methylstyrene, acrylic acid esters, methacrylic acid esters, vinyl acetate, acrylonitrile,
Examples thereof include vinyl chloride, and among these, styrene is particularly preferable.

The copolymer of α, β-unsaturated carboxylic acid anhydride and vinyl compound can be produced by a conventionally known method, but the carboxylic acid anhydride group is uniformly dispersed in the copolymer, In addition, in order to easily suppress the reaction, it is desirable to add a vinyl compound to the α, β-unsaturated carboxylic acid anhydride and cause the reaction.

The reaction can be carried out by a known method, for example, the method disclosed in Japanese Patent Publication No. 48-43664.

That is, α, β-unsaturated carboxylic acid anhydride such as maleic anhydride is previously dissolved in a solvent containing a polymerization initiator, and a vinyl compound such as styrene and a dialkylaniline which is a chain transfer agent are added thereto. It is carried out by dropping at a predetermined ratio or by dissolving a polymerization initiator in a solvent and adding a mixed solution of a chain transfer agent and a monomer mixed in advance.

The temperature is 30 to 100 ° C, and the reaction time is usually about 10 hours.

The molecular weight of the polymer depends on the type of solvent, the amount of the chain transfer agent added, the ratio of the monomer components, the polymerization temperature and the like.

Next, a saturated or unsaturated α-, β-unsaturated carboxylic acid anhydride obtained as described above-reacted with the carboxylic acid anhydride group of the vinyl compound copolymer to block the carboxyl group, or Examples of the saturated monohydric alcohol include alkyl groups having 3 or more carbon atoms, such as propyl alcohol, butyl alcohol, hemosyl alcohol, octyl alcohol, 2-3-dichloro-1-propanol, 2.3-dibromo-1-propanol and allyl alcohol. 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, benzyl alcohol and the like can be mentioned.

Saturated with a copolymer having a carboxylic acid anhydride group, or
The reaction with the unsaturated monohydric alcohol is carried out by adding a saturated or unsaturated monohydric alcohol having 3 or more carbon atoms and, if necessary, a catalyst to the solvent solution of the copolymer while heating and stirring.

The solvent is not particularly limited as long as it dissolves the copolymer, for example, benzene, toluene, aromatic hydrocarbons such as xylene, ketones such as methyl ethyl ketone,
Propylene glycol monoalkyl acetate, dipropylene glycol monoalkyl acetate, etc. are used.

Of these, propylene glycol monoalkyl acetate is preferable.

The reason is that the toxicity is low, the price is high, and the inertness to the product is excellent.

The reaction with the saturated or unsaturated alcohol may be carried out by mixing both or separately.

The ratio of saturated alcohol / unsaturated alcohol and the ratio of both mixtures / α, β-unsaturated carboxylic acid anhydride-vinyl compound copolymer used are the amount of double bond to be imparted and the acid value to be set, that is, to remain. It is set according to the degree of the carboxyl group.

Usually, it is in the range of 0.1 to 1 mol with respect to 1 mol of the acid anhydride group of the copolymer.

Further, the temperature of the copolymer in the solution is appropriately selected so that the resin concentration of the final reaction liquid is 10 to 90% by weight, but 40 to 60% by weight is particularly preferable.

When the concentration of the copolymer in the solvent exceeds 90%, the viscosity of the solution is high, and it is difficult for the uniform reaction to proceed. Conversely, when the concentration of the copolymer is less than 10%, the uniform reaction proceeds. However, it is disadvantageous in terms of productivity such as solvent recovery and equipment scale.

As a catalyst that is optionally used in this esterification reaction, a conventionally known esterification catalyst is used, but a catalyst is not always necessary in a system in which an excessive amount of alcohol is present.

When a catalyst is used, the amount used is 0.00 based on the starting material.
It is 1 to 10% by weight, preferably 0.01 to 1.0% by weight.

If the amount of the catalyst used is less than 0.001% by weight, the effect is small, and conversely, it is not necessary to use an amount exceeding 10% by weight.

The heating is in the range of room temperature to 200 ° C., preferably 40 to 130 ° C., and the reaction time is determined by the reactivity of the saturated or unsaturated monohydric alcohol at the reaction temperature, but in general,
1 to 20 hours is suitable.

By the above reaction, a part of the acid anhydride group portion in the copolymer is esterified to generate a free carboxylic acid group.

Esterification of this carboxylic acid group moiety with an alcohol as described above produces water.

It is known that this type of esterification reaction does not proceed promptly due to an equilibrium reaction unless the produced water is removed out of the system.

In order to remove water from this reaction system, it is possible to remove only water by heating. However, for example, aromatic compounds such as benzene, toluene, xylene, etc., esters such as ethyl acetate, methyl acetate, etc. Water that is not dissolved in can be distilled off by adding it as an entrainer to the reaction system and performing azeotropic dehydration.

The amount of solvent added is preferably 0.3 part or more based on the total volume.

It is desirable to separate the azeotropic solvent / water outside the system and reuse the separated solvent again.

The dehydration esterification reaction with alcohol may be carried out under normal pressure, increased pressure or reduced pressure.

The reaction reactivity is 20 ° C to 200 ° C, preferably in the range of 50 ° C to 150 ° C. The reaction time varies depending on the type of alcohol used in the esterification reaction, but is 1 to 30 hours, preferably 3 to 20 hours. It is within the range of time.

At this time, in order to accelerate the reaction, P-toluenesulfonic acid, lithium acetate, quaternary ammonium salt, tertiary amine zinc and its carboxylate may be used as a catalyst.
The amount used is as described above.

Alcohols used include allyl alcohol, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, and other compounds having a double bond, as well as 2.3-dibromo-1-propanol, propyl alcohol, and hexyl. Alcohol, octyl alcohol,
Benzyl alcohol can be used.

The above series of reactions can be expressed by a general formula as follows.

Reaction of α, β-unsaturated carboxylic acid anhydride (eg maleic anhydride) with vinyl compound (eg styrene) (However, R is a compound residue that does not have an active double bond such as an alkyl group or a benzene nucleus.) Reaction of α, β-unsaturated carboxylic acid anhydride-vinyl compound copolymer with a saturated or unsaturated alcohol Reaction of partially esterified product of α, β-unsaturated carboxylic acid anhydride-vinyl compound copolymer with unsaturated or saturated alcohol (However, each of R'and R "is a compound residue having a double bond such as an allyl group or a compound residue having no double bond such as an alkyl group, x + y = n) As you can see, various primary alcohols,
In particular, an alcohol having a vinyl group or the like and an alcohol having no reactivity can be freely introduced on the chain.

In the above reaction, the reaction between the α, β-unsaturated carboxylic acid anhydride-vinyl compound copolymer and the saturated or unsaturated alcohol and the α, β-unsaturated carboxylic acid anhydride-vinyl compound copolymer part The reaction between the esterified product and the unsaturated or saturated alcohol can be carried out simultaneously as described above.

The saturated or unsaturated alcohol used for esterification of the carboxyl group may be a mixture of two or more kinds.

When the product is dissolved in a desired solvent, for example, a solvent having a relatively high boiling point such as diethylene glycol diacetate dipropylene glycol / monomethyl ether acetate, the product alone is dissolved in these high boiling point solvents. Can be made.

In addition, as a reaction solvent, a predetermined amount of these high boiling point solvents is placed in a reactor, the raw material resin and an alcohol chain are charged, and in addition to this, a necessary amount of toluene is added as an azeotropic dehydration solvent, and toluene / water is distilled off. After the reaction is completed, it is also possible to distill off only the added toluene again and take out the remaining bottom product as a product.

Example-1 600 g of toluene, styrene-maleic anhydride as a α-β-unsaturated carboxylic acid anhydride-vinyl compound copolymer were placed in a separable flask 2 equipped with a stirrer, a thermometer, a dehydration tube and a reflux condenser. Acid copolymer Saturated alcohol adduct (Ar
To SMA1440) 600 gr manufactured by Co Chemical Co., 32 gr of allyl alcohol as an unsaturated alcohol and 0.6 gr of paratoluenesulfonic acid as an esterification dehydration catalyst were added, and dehydration esterification reaction was carried out at 110 ° C for 10 hours.

After completion of the reaction, toluene was distilled off at 50 ° C. and 20 mmHg, and then the resin was taken out.

Allyl alcohol was about 26% reacted.

The molar ratio of each group possessed by the product was as follows. Allyl group: BUO: COOH = 1: 3.85: 2.85 The obtained resin showed high solubility in a solvent such as dipropylene glycol monomethyl ether acetate. The acid value of the resin decreased from 175 to 124.

Comparative Example-1 In a separable flask 2 equipped with a stirrer, a thermometer and a reflux condenser, methyl ether ketone 400gr, allyl alcohol 100gr, styrene-maleic anhydride copolymer (Arco
Chemical-made, SMA1000A) 500 gr, was added and reacted at 80 ° C. for 5 hours.

After completion of the reaction, the mixture was heated at 20 mmHg, and the solvent and unreacted allyl alcohol were distilled off.

The acid value of the obtained resin is 334, and allyl alcohol is 23.
% Was added.

The molar ratio of each group possessed by the product was as follows.

Acid anhydride group: COOH: allyl group = 1.17: 1: 1 Although this resin was dissolved in a solvent such as dipropylene glycol monomethyl ether acetate or dipropylene glycol monomethyl ether acetate, there was a problem that it was difficult to dissolve.

Comparative Example-2 Hydroxyethyl acrylate was used instead of allyl alcohol, and hydroquinone monomethyl ether was added at 0.58 gr.
The same procedure as in Comparative Example-1 was carried out except that the acid value was changed.
A product with 15% hydroxyethyl acrylate added at 350 was obtained.

The molar ratio of each group possessed by the product was as follows.

Acid anhydride group: COOH: HEA = 2.33: 1: 1 This resin was attempted to be dissolved in dipropylene glycol monomethyl ether acetate and dipropylene glycol monomethyl ether acetate, but an insoluble component was produced.

Claims (5)

[Claims] 1. An α, β-unsaturated carboxylic acid anhydride-vinyl compound copolymer as a basic skeleton, and a side chain in the α, β-unsaturated carboxylic acid skeleton is (a) a carboxyl group (b) an unsaturated alcohol. Curable resin which is a mixture of ester group (c) saturated alcohol ester group. 2. The unsaturated alcohol is allyl alcohol,
The curable resin according to claim 1, which is any one selected from hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate. 3. The saturated alcohol is any one selected from propyl alcohol, butyl alcohol, hemosyl alcohol, octyl alcohol, 2-3-dichloro-1-propanol and 2.3-dibromo-1-propanol. The curable resin according to item (1). 4. The curable resin according to claim 1, wherein the α, β-unsaturated carboxylic acid anhydride is maleic anhydride. 5. The method according to claim 1, wherein the vinyl compound is any one selected from styrene, 2-methylstyrene, acrylic acid esters, methacrylic acid esters, vinyl acetate, acrylonitrile and vinyl chloride. The curable resin described.