KR930006080B1 - Process for preparing acrylic group resin having good heat resistance and transparency - Google Patents

Abstract

The heat-resistant transparent acrylic resin contg. at least 5 wt.% methacryl imide gp. is produced by reacting a MMA mono- polymer or a MMA/ethylene-unsatd. monomer copolymer with an ammonium cpd. of urea, 1,3-dimethyl (diethyl) urea, ammonium acetate, ammonium (bi)carbonate or ammonium carbamate, 0.01-15 wt.% cpd. of (R)4NOH [R=H, C1-20 alkyl, cycloalkyl or aryl and 1- 20 wt.% water in the presence of a solvent at 100-350 deg.C. The solvent is pref. benzene, boluene, xylene, methylethyl ketone, ethyleneglycol dimethylether, dimethyl formamide, tetrahydrofuran and/or C1-4 alcohol.

Description

Manufacturing method of heat resistant transparent acrylic resin

The present invention relates to a method for producing a transparent acrylic resin having excellent heat resistance, and more particularly, to prepare a transparent acrylic resin having excellent heat resistance by reacting a methacryl resin with an amidated material in the presence of a catalyst for improving amidation reactivity. It is about a method.

Conventionally, methacryl resin has been used in high performance optical materials, decorative materials, automobiles, electrical appliances, etc. because of its excellent transparency, weather resistance, and mechanical properties. However, since the methacrylic resin has a low heat deformation temperature of 100 ° C. or lower, the use of methacryl resin is limited in fields requiring heat resistance, and thus, the need for improvement of heat resistance has emerged.

As a method of improving the heat resistance of methacrylic resins, 1) acrylic acid, methacrylic acid or ester polymers thereof and primary amines are heated and reacted in the presence of a high boiling point solvent (US Pat. No. 2146209), 2 3) a method of reacting methacryl resin with primary amine in the presence of water (US Pat. No. 3284425), 3) a method of reacting methacryl resin with ammonia or primary amine in an extruder (US Pat. No. 4246374), 4) A method of reacting methacryl resin with liquefied ammonia or primary amine in the presence of a solvent (Japanese Patent Publication No. 63-36696) has been proposed.

However, in the method of (1), since the boiling point of the solvent used is high, complete separation of the solvent from the resulting imidized polymer is difficult on a commercial scale, and as a result, the resulting imide and the polymer are colored to reduce the transparency of the resulting polymer. Let's do it. In the method of (2), imidation reaction using a large amount of water as a dispersion medium separates the water layer and the polymer layer, making it difficult to obtain a uniform imidized polymer, and the reaction occurs at or above the softening point of the acrylic polymer. It is difficult to handle by being entangled with a stirring shaft, and in the method of (3), since the imidation reaction of a high viscosity polymer is performed with a gaseous primary amine, it is difficult to obtain a uniform polymer. In addition, in the method of (4), in order to prevent hydrolysis of the methacryl resin segment, water removal of the solvent, the methyl methacrylate polymer, and the primary amine is required, resulting in an increase in production cost.

Accordingly, in the present invention, the above problems are improved. First, a reaction accelerator for improving the reaction when reacting a methacryl resin with a primary amine or an ammonia compound that generates a primary amine by heating (catalyst) ) To prepare a transparent acrylic resin having excellent heat resistance, and secondly, since water acts as an additive to enhance reactivity with a reaction accelerator (catalyst) without removing water during the imidization reaction, an appropriate amount of water To prepare a transparent acrylic resin having excellent heat resistance, and thirdly, to uniformly react with a solvent capable of dissolving the reactant and the product, to prepare a uniformly imidized methylmethacrylimide polymer to produce an acrylic resin. It has excellent properties such as excellent optical properties, mechanical properties, weather resistance, molding processability and productivity of the resin. It is related with the method of manufacturing heat resistant acrylic resin excellent in transparency, without lowering.

That is, the present invention is added to 0.01 to 15% by weight of the catalyst and 5 to 20% by weight of water in the presence of an ammonia compound and a solvent to generate a primary amine or primary amine in the methacryl resin at a temperature of 100 ~ 350 ℃ It relates to a method for producing a transparent acrylic resin characterized in that the reaction.

The present invention is described in detail as follows.

The ammonia compound which produces | generates the primary amine or primary amine represented by the following general formula (I) to methacryl resin, and the ammonium bicarbonate represented by the following general formula (II), and its derivative represented by general formula (III) Tetraalkylammonium hydroxide is added, and an appropriate amount of water is added to react homogeneously in the presence of a solvent to introduce an imide structure represented by the following general formula (IV) to the methacryl resin to contain a methacrylimide group. By manufacturing the polymer to make a methacryl-imide group, the polymer containing the imidation structural unit preferably 5 weight% or more is manufactured.

Wherein R represents a hydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl, aryl, alkaryl, aralkyl or allyl group of 1 to 20 carbon atoms.

In the present invention, the methacrylimide group-containing polymer is one in which a methacrylimide (dimethylglutarimide) structure is introduced into the side chain of the methacryl resin.

The methacryl resin to which the imide unit is introduced here is an ethylenically unsaturated monomer capable of copolymerizing with methyl methacrylate homopolymer and methyl methacrylate, for example methacrylic acid ester, acrylic acid ester, styrene or α- Methacrylic copolymers such as methyl styrene and maleic anhydride may be used as the methacrylic resin. Thus, most preferably, methyl methacrylate homopolymer, methyl methacrylate and methyl acrylate copolymer, methyl methacrylate and styrene copolymer and methyl methacrylate, styrene and maleic anhydride copolymer may be mentioned.

Although the total amount of methacrylate units in the above-mentioned copolymers is not particularly limited, it is preferable that the content of methyl methacrylate units is at least 50% by weight or more.

As methacrylic acid ester, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, Benzyl methacrylate, aryl methacrylate may be mentioned. As the acrylic ester, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, benzyl acrylate, and aryl acrylate may be mentioned. have. Preferably, the homopolymer of methyl methacrylate is preferable from the viewpoint of transparency and imidization reaction.

As the reaction accelerator (catalyst) used in the present invention, tetraalkylammonium hydroxide is suitable. Preferably, tetramethylammonium hydroxide pentahydrate and tetraethylammonium hydroxide are suitable. Tetraalkylammonium hydroxide acts as a basic catalyst in the reaction system to increase the reactivity of the reacting polymer, thereby increasing the imidation rate of the polymer and relatively relaxing the reaction conditions (reaction temperature and pressure). This excellent transparent acrylic resin can be manufactured. In addition, tetraalkylammonium hydroxide decomposes into trialkylamine and alcohol by heating, so that separation from the polymer is easy. Therefore, the amount of tetraalkylammonium hydroxide used in the preparation of the methylmethacrylimide polymer is in the range of 0.01 to 15% by weight, more preferably 0.1 to 7% by weight.

When the amount of the tetraalkylammonium hydroxide used is 0.01% by weight or less, the amount of the catalyst is too lean so that no catalytic effect occurs, and at 15% by weight or more, the effect of the catalyst is lowered, indicating a drop in physical properties.

As the reaction promoter used in the present invention, water is preferable together with the above catalyst. Since an appropriate amount of water acts as a catalyst in the imidization reaction to facilitate the reaction, the water layer and the polymer layer when the existing water is used as a dispersion medium eliminates uneven imide polymer formation and water removal process by separation. At the same time, by increasing the imidation ratio of the reaction polymer, it is possible to produce a transparent acrylic resin more excellent in heat resistance. Moreover, when using the ammonia compound which produces | generates a primary amine by heating, it acts to increase solubility in the reaction system which is water, and also plays the role which increases the reactivity in imidation reaction. Therefore, the amount of water used in the preparation of the methyl methacrylamide polymer is in the range of 1 to 20% by weight, more preferably 2 to 10% by weight.

When the amount of water used is 1% by weight or less, the reactivity inhibits the heat resistance, and at 20% by weight or more, a non-uniform imidized polymer is obtained by phase separation of the water layer and the polymer layer, and the product is entangled in the axis of the reactor. do.

The solvent used in the present invention does not inhibit the imidization reaction caused by the polymer side chain polymerization, and in the case of the partial imidization reaction, it is necessary not to impart a change to the methacrylic acid or the methyl methacrylate segment. . Furthermore, in order to obtain a uniform imidized polymer by the homogeneous reaction, a solvent capable of dissolving the reactant acrylate polymer, the imidized material and the reaction product imide group-containing polymer is required. In addition, if the boiling point of the solvent is too high, it is difficult to remove the solvent after the completion of the reaction, if it is too low, the pressure is increased so that the boiling point is a solvent in the range of 50 ~ 160 ℃.

Examples of the solvent for the methacryl resin and the methacrylimide group-containing polymer include aromatic hydrocarbon compounds such as benzene, toluene, and xylene, methyl ethyl ketone, ethylene glycol dimethyl ether, diglyme, dioxane, and ketones such as tetrahydrofuran. Compounds, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and butyl alcohol, and single or mixed solvents such as dimethylformamide, dimethyl sulfoxide and dimethylacetamide can be used.

The imidation material which imidates the methyl methacrylate polymer includes ammonia, methylamine, ethylamine, n-propylamine, n-butylamine, heptylamine, hexylamine, cyclohexylamine, octylamine, as primary amines. Nonylamine, decylamine, dodecylamine, hexadecylamine, octadecylamine, isobutylamine, sec-butylamine, t-butylamine, isopropylamine, 2-ethylhexylamine, 2-phenylethylamine, arylamine , Alanine, benzylamine, parachlorobenzylamine, dimethoxyphenylethylamine, aniline, bromoaniline, dibromoaniline, tribromoaniline, chloroaniline, dichloroaniline, trichloroaniline, etc. are used. As the ammonia compound for generating the amine, urea, 1,3-dimethylurea, 1,3-diethylurea, ammonium acetate, ammonium bicarbonate and derivatives thereof are used.

The reaction temperature of the methyl methacrylate resin and the imidized material in the reactor is preferably 100 ° C. or higher and 350 ° C. or lower, more preferably 150 ° C. or higher and less than 300 ° C. When the reaction temperature is 350 ° C. or higher, the decomposition reaction of the methyl methacrylate polymer occurs. At 100 ° C. or lower, the imidation reaction rate is significantly lowered, and the reaction time becomes longer to prepare a polymer containing an imide structure.

In the present invention, the measuring method of the polymer properties was measured as follows, and the measuring method is applied to the following examples.

1) Polymer imidization

It measured on the potassium bromide (KBr) pellet using the infrared spectrum (BIIRAD make, FTIR).

2) The measurement of the amount of imidization (%) of the polymer was calculated by the nitrogen content of the elemental analysis value (PERKIN ELMER MODEL: 240 days).

3) The heat resistance was examined by measuring the glass transition temperature (Dupont Model: 1090).

The present invention will be described in detail with reference to the following Examples.

Example 1

100 parts by weight of methyl methacrylate polymer [Lucky IH-830], 14 parts by weight of methylamine as an imidization material, 7 parts by weight of tetramethylammonium hydroxide pentahydrate as catalyst, 19 parts by weight of distilled water, mixed solvent 455 parts by weight of tetrahydrofuran and 55 parts by weight of methyl alcohol were put in a 1.8 liter autoclave reactor for high temperature and high pressure to sufficiently reflux nitrogen to prevent oxidation while stirring the reaction, and the reaction was stirred at 250 rpm to dissolve the reaction. The reaction was carried out for 3 hours at 200 psi. After completion of the reaction, the solution containing the methyl methacrylimide group-containing polymer was reprecipitated in n-hexane, filtered, and dried sufficiently in a 100 ° C. vacuum dryer to obtain a white powder polymer. As a result of measuring the polymer obtained here in the infrared spectrum to determine the characteristic bands of imide structure methylmethacrylate in 1680㎝ ^-1, 1720㎝ ^-1 was confirmed that the methyl methacrylate polymer imide. Table 1 shows the measurement results of the physical properties of this polymer.

Example 2

Except that the reaction temperature is 190 ℃ was prepared in the same manner as in Example 1, their physical properties are shown in Table 1.

Example 3

Except that the reaction temperature is 210 ℃ was prepared in the same manner as in Example 1, their physical properties are shown in Table 1.

Comparative Example 1

Except that the reaction temperature is 170 ℃ without using a catalyst was prepared in the same manner as in Example 1, their physical properties are shown in Table 1.

Comparative Example 2

Except that the reaction temperature is 190 ℃ was prepared in the same manner as in Comparative Example 1, their physical properties are shown in Table 1.

Comparative Example 3

Except that the reaction temperature is 210 ℃ was prepared in the same manner as in Comparative Example 1, their physical properties are shown in Table 1.

TABLE 1

MMA: Methyl methacrylate monomer

Claims (7)

To the methacryl resin, 0.01-15% by weight of a compound represented by the following general formula (III) and 1-20% by weight of water are added to the methacryl resin in the presence of a solvent to generate a primary amine or a primary ammonia. Method for producing a heat-resistant transparent acrylic resin characterized in that the reaction at 100 ~ 350 ℃ temperature. (R) ₄ NOH (Ⅲ) Wherein R represents a hydrogen atom or a substituted or unsubstituted alkyl, cyclo alkyl, aryl, alkaryl, aralkyl or allyl group of 1 to 20 carbon atoms. The method of claim 1, wherein the methacryl resin is a methyl methacrylate homopolymer, a copolymer of methyl methacrylate and an ethylenically unsaturated monomer. The compound according to claim 1, wherein the primary amine or the ammonia compound that generates the primary amine is a compound represented by the following general formula (I): urea, 1,3-dimethylurea, 1,3-diethylurea, ammonium A method for producing a heat-resistant transparent acrylic resin, characterized in that the acetate, ammonium carbonate, ammonium carbamate and ammonium bicarbonate represented by the general formula (II) and derivatives thereof. RNH ₂ (I) RNH ₃ HCO ₃ (II) Wherein R represents a hydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl, aryl, alkaryl, aralkyl, allyl group of 1 to 20 carbon atoms. The method according to claim 1, wherein the solvent has a boiling point of 50 to 160 ° C. The method for producing a heat resistant transparent acrylic resin according to claim 1 or 2, wherein the content of the methyl methacrylate unit is 50% by weight or more as the methacryl resin. The solvent according to claim 1 or 3, wherein the solvent is benzene, toluene, xylene, methyl ethyl ketone, ethylene glycol dimethyl ether, diglyme, dioxane, detrahydrofuran, dimethylformamide, dimethyl sulfoxide, dimethylacetamide, Method for producing a heat-resistant transparent acrylic resin, characterized in that the solvent used alone or in combination of two or more of methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol. The method for producing a heat resistant transparent acrylic resin according to claim 1, wherein the polymer containing a methacrylimide group represented by the following general formula (IV) as a product contains 5% by weight or more of imidized structural units.

Wherein R represents a hydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl, aryl, alkaryl, aralkyl or allyl group of 1 to 20 carbon atoms.