KR930005999B1 - Process for preparing acrylic - Google Patents

Abstract

The heat-resistant transparent acrylic resin is produced by reacting a methacryl resin with a primary amine of formula RNH2, urea, 1,3-dimethyl (diethyl) urea, ammonium acetate or ammonium bicarbonate of formula RNH3HCO3, and a distilled water in the presence of a solvent at 180-350 deg.C. In the formulas, R is H, C1-20 alkyl, cycloalkyl, aryl, or aralkyl. The methacryl resin is pref. MMA mono-polymer of MMA/ethylene - unsatd. monomer copolymer.

Description

Manufacturing method of heat resistant transparent acrylic resin

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

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 resin, 1) a method of reacting acrylic acid, methacrylic acid or ester polymers thereof and primary amine in the presence of a high boiling point solvent (US Patent No. 2146209) 2) Methacrylic Reaction of resin with primary amine in the presence of water (US Pat. No. 3284425) 3) Reaction of methacrylic resin with ammonia or primary amine in an extruder (US Pat. No. 4246374) 4) Methacrylic resin And a method of reacting the deteriorated ammonia or primary amine in the presence of a solvent (Japanese Patent Publication No. 63-36696) and the like have 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 the resultant imidized polymer is colored to reduce the transparency of the resulting polymer. . In addition, in the method of (2), a large amount of water is used as a dispersion medium to cause the imidization reaction to separate the water layer and the polymer layer, thereby making it difficult to obtain a uniform imidized polymer, and the reaction takes place above the softening point of the acrylic polymer. Is entangled in the stirring shaft and difficult to handle, and in the method of (3), it is difficult to obtain a homogeneous polymer because the imidization reaction of the polymer having high viscosity is performed with the gaseous primary amine. In addition, in the method of (4), in order to prevent hydrolysis of the methacryl resin segment, water removal of the solvent, methyl methacrylate polymer, and primary amine is required, and thus there is a problem such as an increase in production cost.

Therefore, 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 (catalytic effect) ) To prepare a transparent acle resin having excellent heat resistance, and secondly, it is not necessary to remove water from the reactants during the imidization reaction, and rather, it acts as a catalyst to promote the imidization reaction by adding 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 reactants and the product, to prepare a uniformly amidated methacryl imide polymer to produce an acrylic resin. Excellent optical properties, mechanical properties, weather resistance, molding processability, productivity, etc. It is related with the method of manufacturing heat resistant acrylic resin excellent in transparency.

That is, the present invention is characterized by reacting at a temperature of 180 to 350 ℃ by adding 2 to 20 parts by weight of water (distilled water) in the presence of ammonia compound and primary solvent to generate a primary amine or primary amine to the methacrylic resin It relates to a method for producing a heat resistant transparent acrylic resin.

The present invention is described in detail as follows. As an ammonia compound which generates a primary amine or a primary amine represented by the following general formula (I) to the methacryl resin, and an ammonium bicarbonate represented by the following general formula (II) and derivatives thereof and an imidization reaction accelerator, Distilled water) and reacted uniformly in the presence of a solvent to introduce a imide structure represented by the following general formula (III) to the methacryl resin to prepare a polymer containing a methacrylimide group. The polymer is preferably prepared containing at least 10% by weight, more preferably at least 20% by weight of imidized structural units.

Wherein R represents a hydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl, aryl, alkaryl, aralkyl, 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.

-메틸스티렌, 그리고 무수말레인산 등과의 메타크릴성 공중합체 등이 메타크릴이미드 그룹 함유 공중합체를 생성하기 위한 메타크릴성 수지로서 사용될 수 있다. 따라서, 가장 바람직하게는 메틸메타크릴레이트 단일중합체, 메틸메타크릴레이트와 메틸메타크릴레이트 공중합체, 메틸메타크릴레이트와 스티렌공중합체 및 메틸메타크릴레이트, 스티렌 그리고 무수말레인산 공중합체가 언급될 수 있다.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, such as methacrylic acid ester, acrylic acid ester, styrene or

Methacrylic copolymer with methyl styrene, maleic anhydride and the like can be used as the methacrylic resin for producing the methacrylic imide group-containing copolymer. Thus, most preferably, methyl methacrylate homopolymer, methyl methacrylate and methyl methacrylate copolymer, methyl methacrylate and styrene copolymer and methyl methacrylate, styrene and maleic anhydride copolymer may be mentioned. .

Although the content of methyl methacrylate units in the above-mentioned copolymer 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. . Preferably, homopolymers of methyl methacryl are preferred in view of transparency and imidization reaction.

As the reaction accelerator used in the present invention, water (distilled water) is preferable. Since an appropriate amount of water acts as a catalyst in the imidization reaction to facilitate the reaction, it eliminates the process of producing uneven light polymer and removing water by separating the water layer and the polymer layer when the existing water is used as a dispersion medium. 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. Furthermore, in the case of using an ammonia compound that generates a primary amine by heating, water acts to increase the solubility in the reaction system, thereby increasing the reactivity (reaction rate) during the imidization reaction. Therefore, in the preparation of the methylmethacrylimide polymer, water is preferably used in an amount of 5 to 20 wt%, more preferably 7 to 15 wt%.

If the water is less than 5% by weight, 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. .

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

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, ketones such as tetrahydrofuran, and ethers. 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 for imidating the methyl methacrylate polymer is a primary amine, which is ammonia, methylamine, ethylamine, n-propylamine, n-butylamine, heptylamine, hexylamine, cyclohexylamine, octylamine , Nonylamine, decylamine, dodecylamine, hexadecylamine, octadecylamine, isobutylamine, sec-butylamine, t-butylamine, isopropylamine, 2-ethylhexylamine, 2-phenylethylamine, aryl Amine, alanine, benzylamine, parachlorobenzylamine, dimethoxyphenylethylamine, aniline, bromoaniline, dibromoaniline, tribromoaniline, chloroaniline, dichloroaniline, trichloroaniline, and the like, are used. As the ammonia compound for generating a tertiary amine, urea, 1,3-dimethylurea, 1,3-diethylurea, ammonium acetate, ammonium bicarbonate and derivatives thereof are used.

In the reactor, the reaction temperature of the methyl methacrylate resin and the imidized material is suitably 180 ° C or more and 350 ° C or less, and more preferably 200 ° C or more and less than 300 ° C. When the reaction temperature is 350 ° C. or higher, the decomposition reaction of the methyl methacrylate polymer occurs, and at 180 ° C. or lower, the imidization reaction rate is remarkably lowered, resulting in a longer reaction time for preparing a polymer containing an imide structure.

In the present invention, the measurement method of the characteristics of the polymer was measured by the following, and the measurement method is applied to the following examples.

1) Polymer imidization

Measurement was carried out on potassium bromide (KBr) pellets using an infrared spectrum (BIORAD system, FTIR).

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

3) The heat resistance was measured 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

Methyl methacrylate polymer Co., Ltd. Lucky, 100 parts by weight of IH-8301, 58 parts by weight of cyclohexylamine as imidization material, 100 parts by weight of water (distilled water) as imidization reaction accelerator, and 456 parts by weight of tetrahydrofuran as solvent In addition, 58 parts by weight of methyl alcohol was put in a high-temperature, high-pressure autoclave to stir the reaction sufficiently while refluxing nitrogen to prevent oxidation, and then stirred at 250 rpm to dissolve the reaction to wait for 3 hours at 200 ° C. After the completion of the reaction, the solution containing the methacrylimide group-containing polymer was reprecipitated in n-hexane, filtered, and dried sufficiently in a 100 ° C reduced pressure dryer to obtain a white powder polymer. The polymer obtained here was measured by the infrared spectrum, a methacrylic at 1680cm ^-1, 1700cm ^-1 and 1720cm ^-1 determine the characteristic bands of imide structures, methacrylic this confirmed the mid polymer. The measurement results of the physical properties of this polymer are shown in Table 1.

Example 2

Except for 63 parts by weight of bicarbonate for ammonia as an imidized substance, 60 parts by weight of water (distilled water) as an imidization reaction accelerator, 340 parts by weight of tetrahydrofuran as a solvent, 146 parts by weight of methane alcohol, and a reaction temperature of 230 ° C. Prepared in the same manner as in Example 1, their physical properties are shown in Table 1.

Example 3

47 parts by weight of bicarbonate for ammonia as an imidized substance, 60 parts by weight of water (distilled water) as an imidization reaction accelerator, 340 parts by weight of tetrahydrofuran as a solvent, 146 parts by weight of methyl alcohol, and a reaction temperature of 230 ° C. Prepared in the same manner as in Example 1, their physical properties are shown in Table 1.

Example 4

Except that 31 parts by weight of bicarbonate for ammonia as an imidized substance, 60 parts by weight of water (distilled water) as an imidization reaction accelerator, 340 parts by weight of tetrahydrofuran as a solvent, 146 parts by weight of methyl alcohol, and a reaction temperature of 230 ° C. Prepared in the same manner as in Example 1, their physical properties are shown in Table 1.

Example 5

15 parts by weight of bicarbonate for ammonia as an imidized substance, 60 parts by weight of water (distilled water) as an imidization reaction accelerator, 340 parts by weight of tetrahydrofuran as a solvent, 146 parts by weight of methanol, and a reaction temperature of 230 ° C. Prepared in the same manner as in Example 1, their physical properties are shown in Table 1.

Comparative Example 1

Table 1 shows the reaction conditions under the same reaction conditions as in Example 1, using 58 parts by weight of cyclohexylamine, 456 parts by weight of tetrahydrofuran, and 58 parts by weight of methanol as the imidized material.

Comparative Example 2

The reaction time results are shown in Table 1 using 63 parts by weight of the imidized substance Ammonium bicarbonate, 340 parts by weight of tetrahydrofuran, and 146 parts by weight of methanol under the same reaction conditions as in Example 1.

Comparative Example 3

Table 1 shows the reaction conditions of 100 parts by weight of the MMA polymer using the same reaction conditions as in Example 1 using 47 parts by weight of the imidized substance Ammonium bicarbonate, 340 parts by weight of tetrahydrofuran, and 146 parts by weight of methanol.

[Comparative Example 4]

Under the same reaction conditions as in Example 1, the reaction time results are shown in Table 1 using 100 parts by weight of the MMA polymer and 31 parts by weight of the imidized substance Ammonium bicarbonate, 340 parts by weight of tetrahydrofuran, and 146 parts by weight of methanol.

[Comparative Example 5]

Table 1 shows the reaction conditions of 100 parts by weight of the MMA polymer using the same reaction conditions as in Example 1 using 15 parts by weight of the imidized substance Ammonium bicarbonate, 340 parts by weight of tetrahydrofuran, and 146 parts by weight of methanol.

Comparative Example 6

Under the same reaction conditions as in Example 1, 100 parts by weight of the MMA polymer was reacted using 63 parts by weight of the imidized substance Ammonium bicarbonate, 25 parts by weight of water (distilled water), 340 parts by weight of tetrahydrofuran, and 146 parts by weight of methanol. 1 is shown.

Comparative Example 7

Under the same reaction conditions as in Example 1, the result of reacting 100 parts by weight of the MMA polymer with 63 parts by weight of the imidized substance Ammonium bicarbonate, 250 parts by weight of water (distilled water), 340 parts by weight of tetrahydrofuran, and 146 parts by weight of methanol was obtained. Table 1 shows.

Comparative Example 8

Table 1 shows the reaction conditions of 100 parts by weight of the MMA polymer using the same reaction conditions as in Example 1 using 63 parts by weight of the imidized substance Ammonium bicarbonate and 380 parts by weight of water (distilled water).

TABLE 1

** MMA: Methyl methacrylate polymer

*** Unable to measure glass transition temperature due to polymer clumping on stirring shaft

Claims (7)

Heat-resistant transparent acrylic resin, characterized in that 5-20% by weight of water (distilled water) is added to the methacryl resin to generate a primary amine or a primary amine in the presence of a solvent. Manufacturing method. The method for producing a heat resistant transparent acrylic resin according to claim 1, wherein the methacryl resin is a methyl methacrylate homopolymer, a copolymer of methyl methacrylate and an ethylenically unsaturated monomer. The method of claim 1, wherein the primary amine is a compound represented by the following general formula (I), and the ammonia compound that generates the primary amine includes urea, 1,3-dimethylurea, 1,3-diethylurea, and ammonia. A method for producing a heat-resistant transparent acrylic resin characterized in that the ammonium bicarbonate represented by um acetate and 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 for producing a heat resistant transparent acrylic resin 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 4, wherein the solvent is benzene, toluene, xylene, methyl ethyl ketone, ethylene glycol dimethyl ether, diglyme, dioxane, tetrahydrofuran, dimethylformamide, dimethylsulfoxide, dimethylacetamide, methyl Method of producing a heat-resistant transparent acrylic resin, characterized in that the solvent used alone or in mixture of two or more of alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol. The method of producing a heat resistant transparent acrylic resin according to claim 1, wherein the polymer containing a methacrylimide group represented by the following general formula (III) contains at least 10% by weight of imidized structural units.

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