JPS63314216A - Preparation of curable resin - Google Patents

Abstract

PURPOSE:To prepare the title resin without causing the product to become turbid or gelled in the absence of a solvent, by reacting a specified acid anhydride group-contg. copolymer with an unsatd. alcohol having both OH and (meth)acryloyl groups. CONSTITUTION:An unsatd. polybasic acid anhydride (b) (e.g., maleic anhydride) and a chain transfer agent (c) (e.g., mercaptan) are added to a polymerizable monomer soln. (a) (e.g., styrene) in an amt. of 1-50mol. per mol. of the component (b) successively in a total of 1-10hr, so that a bulk copolymn. is carried out at 30-200 deg.C to give an acid anhydride group-contg. copolymer A having a degree of polymn. of 50-2,000. The component A is reacted with an unsatd. alcohol B (e.g., 2-hydroxyethyl methacrylate) having both OH and (meth)acryloyl groups which can react with the acid anhydride group in the presence of a polymn. initiator C (e.g., hydroquinone) and an esterification catalyst D (e.g., triethylamine) at 50-150 deg.C.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is an improvement of a curable resin having a (meth)acryloyl group in a side chain, which is useful for various applications such as molded products, adhesives, and paints. The present invention relates to a manufacturing method according to the present invention.

[Conventional technology]

An acid anhydride group-containing copolymer obtained by copolymerizing an unsaturated polybasic acid anhydride and a polymerizable monomer is reacted with an unsaturated alcohol having a hydroxyl group and a (meth)acryloyl group, and the necessary It was previously proposed by one of the inventors of the present invention that a curable resin having (meth)acryloyl groups in the side chain can be obtained by reacting an epoxy compound with the remaining carboxyl groups accordingly (Tokuko Sho et al. 47-
(See Publication No. 25470).

However, in this method, the copolymerization and esterification reactions are carried out in the presence of an organic solvent for ease of reaction operation. Therefore, since the obtained resin contains a solvent, there is a problem that the solvent scatters during curing, which is unfavorable from a public health standpoint. Furthermore, if the solvent is to be recovered, it is difficult to avoid high costs.

Therefore, a method can be considered in which copolymerization of an unsaturated polybasic acid anhydride and a polymerizable monomer is carried out in bulk, and then esterification with an unsaturated alcohol is carried out in the absence of a solvent. Due to the high rate of copolymerization of the product, the product becomes cloudy and glued using conventional methods, making it impossible to stably produce a curable resin with good physical properties.

[Problem that the invention seeks to solve]

The present invention involves adding an unsaturated alcohol having a hydroxyl group and a (meth)acryloyl group to an acid anhydride group-containing copolymer obtained by copolymerizing an unsaturated polybasic acid anhydride and a polymerizable monomer. In this method, a curable resin having a (meth)acryloyl group in the side chain is produced by reacting an epoxy compound with the remaining carboxyl group as necessary, without using any solvent in the entire reaction process. The object of the present invention is to provide an improved method for producing a curable resin that does not cause problems of cloudiness and deltation even when it is carried out.

[Means for solving problems]

The method for producing an improved curable resin of the present invention involves sequentially adding an unsaturated polybasic acid anhydride together with a chain transfer agent to a polymerizable monomer liquid in the absence of a solvent during all reaction steps. It is characterized by polymerizing and then reacting the obtained acid anhydride group-containing copolymer with an unsaturated alcohol and, if necessary, an epoxy compound, and by this method, it is possible to prevent the occurrence of clouding and gluing during the reaction. It has become possible.

[Effect]

The rate of copolymerization of unsaturated polybasic acid anhydrides such as maleic anhydride with polymerizable monomers such as styrene is much faster than the rate of polymerization of styrene itself, so maleic anhydride, styrene, and mercaptan are simultaneously charged from the beginning of the reaction. When polymerized, a styrene-maleic anhydride copolymer is produced at the initial stage of the reaction, and when maleic anhydride is consumed, only polystyrene is produced. As a result, the polymerization system becomes cloudy. In addition,
Copolymers with a high maleic anhydride content tend to be highly glued when reacted with unsaturated alcohols to form ring-opening monoesters, although the reason is not necessarily clear.

As an improvement to the above method, a method of sequentially adding maleic anhydride may be considered, but according to the experiments of the present inventors, this method reduces cloudiness caused by non-uniformity of the polymerization system, but the reason is not clear. It doesn't, but it won't go away completely. Furthermore, at the final stage of the copolymerization reaction, mercaptan is consumed, resulting in the formation of a copolymer with a high degree of polymerization, increasing the viscosity of the resin liquid, which significantly impairs workability, and causing unsaturated alcohol and It was found that gluing occurred during the reaction.

Similarly, we tried adding mercaptan sequentially, but
It was not possible to solve the problems of clouding at the end of the copolymerization and gluing during the esterification reaction.

Based on the above facts, the present inventors have determined that in the absence of a solvent,
In order to prevent clouding and gluing, it is necessary to produce a styrene-maleic anhydride copolymer having an extremely uniform copolymerization composition and an appropriate degree of polymerization, and then esterify this copolymer with an unsaturated alcohol. Knowing that this is essential, they completed the method of the present invention, which is characterized by sequentially adding maleic anhydride and mercaptan to styrene.

Maleic anhydride is typical of the polymerizable unsaturated polybasic acid anhydride used in the method of the present invention.

In addition, itaconic anhydride, citraconic anhydride, etc.
Can be used as needed.

Polymerizable monomers that can be copolymerized with the polymerizable unsaturated polybasic acid may be liquid under copolymerization conditions, such as vinyl aromatics such as styrene, vinyltoluene, and chlorostyrene, acrylic acid, and Methacrylic acid and their methyl,
In addition to esters with ethyl, butyl, hexyl or octyl alcohol, vinyl acetate, acrylonitrile, acrylamide and the like can be mentioned. It is also possible to use two or more of these in combination.

The usage ratio of the polymerizable unsaturated polybasic acid anhydride and the polymerizable monomer is 1 to 50 moles of the polymerizable monomer per 1 mole of the unsaturated polybasic acid anhydride. preferable. If the amount is 50 moles or more, the distance between crosslinks becomes too wide, resulting in slow curability and difficulty in obtaining a useful cured product.

Copolymerization is carried out by sequentially adding an unsaturated polybasic acid anhydride to a polymerizable monomer liquid together with a chain transfer agent over a period of 1 to 10 hours at 30 to 200°C, but the sequential addition is carried out as uniformly as possible. This is desirable.

Chain transfer agents used in the method of the present invention are not particularly limited, but include methyl mercaptan, ethyl mercaptan, n- or i-propyl mercaptan, n""tse
Alkyl mercaptans such as e- or t-butyl mercaptan, n- or i-dodecyl mercaptan, and lauryl mercaptan; adducts of alkylene oxides and hydrogen sulfide such as ethanethiol and furo/IP mercaptan;
Preferred are mercato-substituted fatty acids such as 2-mercagutoacetic acid and 2-mercaptopropionic acid, and esters of these with 2-ethylhexyl alcohol, etc., added in an amount of 0.01 to 3 parts by weight per 100 parts by weight of monomer. be done.

The copolymerization reaction can also be carried out by adding organic peroxides and azobisnitriles, which are commonly used in radical polymerization, but it is better to carry out thermal polymerization without a catalyst and only by heating, since there will be no residue left in the next esterification step. Since there is no catalyst, the polymerization inhibitor acts effectively and prevents gluing, which is advantageous.

The acid anhydride group-containing copolymer thus obtained has a uniform copolymerization composition and an appropriate degree of polymerization, and is used in the next esterification reaction step. The degree of polymerization is suitably about 50 to 2.000. If the degree of polymerization is lower than 50, the physical properties of the cured product of the curable resin, especially the impact resistance, will be low;
If the degree of polymerization is higher, the reaction solution will have a higher viscosity, making it inconvenient to handle and more likely to form into glues.

Next, an unsaturated alcohol having a hydroxyl group and a (meth)acryloyl group that reacts with the acid anhydride group is added to the acid anhydride group-containing copolymer at 50 to 150°C in the presence of a polymerization inhibitor and an esterification catalyst. By reacting at high temperature, a copolymer having a (meth)acryloyl group and a carboxyl group in the side chain is produced.

Furthermore, it is also possible to esterify the generated carboxyl group with an epoxy compound, if necessary.

The unsaturated alcohol used in the method of the present invention includes 2
-hydroxyethyl acrylate, 2-hydroxyglobyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, and the like.

Regarding the reaction ratio between the unsaturated alcohol and the acid anhydride group-containing copolymer, it is desirable that the acid anhydride groups in the copolymer and the hydroxyl groups in the alcohol are substantially equivalent; In fact, there is less risk of gluing if there is too much. Practically, it is allowed to react in a range of 0.9 to 2.0 equivalents.

During the reaction, it is necessary to add a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, or phenothiazine. Also useful is the use of esterification catalysts such as tertiary amines, amine salts, quaternary ammonium salts, metal salts, and the like.

Furthermore, the presence of free carboxyl groups is undesirable when the physical properties of the curable resin are required, such as when the cured product is required to have alkali resistance. It is recommended that As the epoxy compound, an epoxy compound having a polymerizable unsaturated bond is suitable from the viewpoint of curability of the curable resin. Typical examples include glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, and vinylcyclohexene monoepoxide. When allyl glycidyl ether is used, the resin exhibits air drying properties and is suitable for use as a room temperature or heat curing type paint. Further, when glycidyl methacrylate is used, the crosslinking density can be increased, and it is useful in the field of FRP, which requires chemical resistance. Furthermore, a saturated epoxy compound that easily reacts with carboxyl groups can also be used in combination. As an example, there are three UO companies in the United States under the trade names of UNOX 201, 206, and 207.

Yunox 201 Yunox 206 ■ Yunox 207 The curable resin according to the present invention can also be cured by copolymerizing with a monomer as a monomer solution,
It is also possible to carry out crosslinking by polymerizing the unsaturated bonds of the polymer without using a monomer in combination.

Representative examples of the above monomers include styrene, vinyltoluene, chlorostyrene, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tertiary butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, Ethyl methacrylate, n-7'thyl methacrylate, isobutyl methacrylate, tertiary butyl methacrylate, 2-ethylhexyl methacrylate,
lauryl methacrylate, cyclohexyl methacrylate,
Examples include benzyl methacrylate, tetrahydrofurfuryl methacrylate, vinyl acetate and vinyl propionate.

Furthermore, the curable resin of the present invention can be used in combination with fillers, reinforcing materials, mold release agents, colorants, curing agents, accelerators, stabilizers, etc., as necessary, to form various molded products, laminates, adhesives, and coatings. Can be widely used for shapes etc.

〔Example〕

Examples will be described below to further specifically explain the present invention. Descriptions in the text are expressed on a weight basis unless otherwise specified.

Example 1 Styrene 280! Weigh out 30% of maleic anhydride in a nitrogen stream.
．． 9 and lauryl mercaptan 3I was uniformly added dropwise over 4 hours.

After completion of the dropwise addition, polymerization was carried out at 120°C for 30 minutes, and then the air flow was switched to, and 0.15.5' of hydroquinone was added to stop the polymerization.

A colorless and transparent styrene-maleic anhydride copolymer with a solids content of 42% was obtained.

The average molecular weight measured by GPC was 27,000.

The distribution was a normal distribution type as shown in FIG. 1, and it was recognized that a uniform copolymer was obtained.

To this copolymer, 2-hydroxyethyl methacrylate 47 and 1 g of triethylamine were further added,
The reaction was carried out at 100°C for 5 hours.

As a result of infrared analysis, it was estimated that about 70% of the acid anhydride groups in the polymer had reacted (see Figures 2 and 3).

A curable resin (3) having a methacryloyl group in the side chain and having a Hazen color number of 200 and a viscosity of 6.9 poise was obtained.

A mixture of 100 parts of hardenable resin, 2 parts of +328E from Kayaku Nuri Co., Ltd. as an organic peroxide, and 1 part of cobalt naphthenate was glued in 55 minutes and slowly generated heat.
The maximum exothermic temperature reached 113°C.

Molding of cast products based on JIS standards is further carried out at 120℃, 2
Made by curing after hours.

The physical properties of the obtained cured resin were as shown in Table 1.

Table 1 Bending modulus of elasticity (kg/■2) 3 parts 0 Raku M impact value (K Chi Ryu) 3-4 Heat distortion temperature ('C) 114 Comparative example 1 Stirrer, reflux condenser, gas introduction tube, thermometer Styrene 280 in an 11g rubber flask with a j,
Maleic anhydride 30.9, lauryl mercaptan 3g,
was charged and polymerized at 120° C. for 5 hours in a nitrogen stream. Next, the air flow was switched to, and 0.14M7 of hydroquinone was added to stop the polymerization.

A cloudy polymer solution with a solid content of 44% was obtained.

Further, 43 g of 2-hydroxyethyl methacrylate and triethylamine II were added to this polymerized polymer at 100°C.
When the reaction was carried out, it became dull after 2 hours and 10 minutes, and a curable resin having a methacryloyl group in the side chain could not be obtained.

Example 2 An 11-cell tube equipped with a stirrer, a thermometer, an inlet tube, a reflux condenser, and a dropping funnel. Put 208g of styrene into a rubble flask, and place 30F maleic anhydride in a nitrogen stream.
A mixture of methyl methacrylate 70I and 3.5 g of 2-ethylhexyl 2-mercazotoacetate was uniformly dropped and refluxed over 4 hours, and then heated at 120'C for an additional hour. Next, the air flow was switched to, and 0.2 g of hydroquinone was added to stop the polymerization.

A colorless, transparent liquid copolymer having a solid content of 46 cm was obtained.

In this copolymer, 2-hydroxyzorobylmethac+)
v -t48 y, noguradolenesulfonic acid 1.5I
was added and reacted at 100 to 105° C. for 5 hours. As a result of infrared analysis, it was estimated that about 60% of the acid anhydride groups had reacted.

A curable resin having a methacryloyl group in the side chain with a Hazen color number of 150 and a viscosity of 22.4 Boyes (B3 was obtained) To 100 parts of the curable resin (B), 1.5 parts of peroxypivalate as a catalyst and heated at 70℃ for 4 hours.
The appearance of the cured resin was almost colorless and transparent, and its physical properties were as shown in Table 2.

Table 2 Bending strength 11.4 Y/■2 (average) Bending modulus of elasticity 310 kg/X2 Elongation rate
2.8 (%) Tensile strength 5.9 Rij2 Answer Ruby 4I impact value 2.7 kgcm/
cm2 Heat deformation temperature 107 °C In this case, as in Comparative Example 1, when the entire formulation was charged and reacted at once, the resulting polymer became cloudy, and it took just 1 hour and 40 minutes after addition of hydroxyglopyl methacrylate.
It has been converted into a file.

Example 3 Methyl methacrylate 300I was charged into an 11-cell A' rubble flask equipped with a stirrer, a reflux condenser, a heating dropping funnel, and a thermometer with a gas introduction tube, and the mixture was heated at 90°C in a nitrogen stream.
After incubation, add maleic anhydride 3 from the heating dropping funnel.
011 A molten mixture of 4 g of lauryl mercaptan is added dropwise over a period of 5 hours. After completion of the dropping, polymerization was carried out for 1 hour. Next, the air flow was switched to, and 0.15 Il of hydroquinone was added to stop the polymerization.

A colorless and transparent copolymer having a solid content of 44 was obtained.

In the following, 2~hydroxyethyl acrylate 23I, iriethylamin y 1.5,! Add i' and heat to 100°C.

After reacting for 5 hours, infrared analysis revealed that about 85% of the acid anhydride group
% was judged to have disappeared.

The unsaturated polymer C) obtained by adding 100 I of trimethylolgulon triacrylate was slightly yellow in color and had a viscosity of 47 poise.

To 100 parts of the unsaturated polymer (C), 3 parts of Glochia≠1173 manufactured by Merck & Co., Ltd. was added as a photoreaction initiator to prepare a photocurable resin.

This photocurable resin was applied as a poultice to a thickness of 02 m/m on a Vinplite steel plate, and placed under an ultraviolet irradiation lamp with an output of 50 kW.
0 crn was passed at 2 mA). Curing was completed in one go, and the wet film hardness was 4-5H.

〔Effect of the invention〕

According to the method of the present invention, a solvent-free curable resin can be stably obtained without causing cloudiness or scaling, and the obtained resin can give a cured product with excellent heat resistance and impact resistance. It is extremely useful for various applications such as various molded products, adhesives, and paints.

[Brief explanation of drawings]

Figure 1 is a GPC measurement chart of the styrene-maleic anhydride copolymer produced in Example 1, and Figures 2 and 3 are the styrene-maleic anhydride copolymer and
- Infrared analysis charts of the reaction solution before and 5 hours after the start of the reaction with hydroxyethyl methacrylate are shown.

Claims (2)

[Claims] (1) An acid anhydride group-containing copolymer obtained by copolymerizing a polymerizable unsaturated polybasic acid anhydride and a polymerizable monomer that can be copolymerized therewith has a hydroxyl group that reacts with the acid anhydride group. In a method for producing a curable resin having a (meth)acryloyl group in a side chain by reacting an unsaturated alcohol having a (meth)acryloyl group and a (meth)acryloyl group, in the absence of a solvent, an unsaturated alcohol is added to the polymerizable monomer liquid in the absence of a solvent. A solvent-free curable product characterized by sequentially adding a saturated polybasic acid anhydride together with a chain transfer agent to cause bulk copolymerization, and then reacting the resulting acid anhydride group-containing copolymer with an unsaturated alcohol. Method of manufacturing resin. (2) Claim 1 characterized in that the carboxyl group produced by the reaction between the acid anhydride group-containing copolymer and the unsaturated alcohol is esterified with an epoxy compound.
A method for producing a curable resin as described in Section 1.