JPH07252329A - Heat-resistant methacrylic resin - Google Patents

Abstract

PURPOSE:To obtain a methacrylic resin improved in impact resistance and solvent resistance without detriment to the inherent properties by grafting a monomer mixture based on methyl methacrylate onto a partially hydrogenated polybutadiene in a specified manner. CONSTITUTION:This resin is the one comprising a partially hydrogenated polybutadiene having a degree of hydrogenation of 15-90% and a copolymer comprising 80-99.9wt.% methyl meth-acrylate and 0.1-20wt.% other vinyl monomers copolymerizable therewith, wherein the content of insolubles is 1-50wt.% when fractionated with acetone, the content of insolubles is 70-100wt.% when the acetone insolubles are fractionated with toluene, and the degree of swelling in toluene is 1-10. This resin has wide industrial applicability, is improved in impact resistance and solvent resistance without detriment to the excellent properties, such as weather resistance and appearance, inherent in the methacrylic resin, and therefore, it can be extensively used in indoor and outdoor applications.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a methacrylic resin having excellent impact resistance. More specifically, the impact resistance and solvent resistance of the methacrylic resin are maintained, while maintaining the excellent characteristics such as the excellent weather resistance, surface gloss of the molded product, rigidity, sharpness of color tone, and transparency as required. A methacrylic resin having improved properties.

[0002]

Methacrylic resin has excellent weather resistance, rigidity, and
Since it has the appearance of a molded product, it is widely used indoors and outdoors, but it is a brittle polymer by nature and causes problems due to insufficient impact strength depending on the usage. There is. Studies for improving impact resistance of methacrylic resin have been conducted for a long time, and a method of graft-polymerizing a monomer containing methyl methacrylate as a main component to polybutadiene or a diene copolymer (JP-B-46).
No. 18491, Japanese Patent Laid-Open No. 55-147514, Japanese Patent Laid-Open No. 55-123612), and a method of blending a multi-layered acrylic rubber with a methacrylic resin (Japanese Patent Publication No. 55-27676, Japanese Patent Laid-Open No. 3-199213). Japanese Patent Publication No. 58-1694, Japanese Patent Publication No. 59-366
45, Japanese Patent Publication 59-36646, Japanese Patent Publication 6
No. 3-8983, Japanese Patent Publication No. 62-41241), grafting a monomer containing methyl methacrylate as a main component to a rubber-like polymer obtained by hydrogenating a block copolymer composed of an aromatic vinyl and a conjugated diene compound. Polymerization method (JP-A-1-163209, JP-A-2-3024)
59) and the like are known.

The method using the first polybutadiene or diene copolymer has improved impact resistance like ABS resin and impact-resistant polystyrene, and can be industrially produced by a similar process. However, since the rubber component contains many double bonds and benzene rings which are unstable to light, there is a problem in that the weather resistance, which is an original feature of the methacrylic resin, is significantly lowered.

An attempt to improve the weather resistance, which is a drawback of the first method, is a third method using a rubbery polymer obtained by hydrogenating a block copolymer composed of aromatic vinyl and a conjugated diene compound. . Since the double bond of the rubber component is substantially eliminated by hydrogenation, the weather resistance of the conjugated diene block is certainly improved, but since it contains aromatic vinyl, the weather resistance discoloration is larger than that of methacrylic resin, and Since the cross-linking reaction of the rubber component becomes difficult to proceed remarkably due to the decrease of double bonds,
Even if the desired rubber particles are formed in the polymerization process, the particles are deformed or destroyed by the mechanical shearing force applied during extrusion or injection molding, and the surface gloss and transparency of the molded product become poor. Will end up. In these patent specifications, there is no technical disclosure regarding the crosslinking of the rubber component, including the examples. For this reason, the third method is not a technology for improving the impact resistance of methacrylic resin from the industrial viewpoint.

On the other hand, the method of blending the second multi-layered acrylic rubber and the methacrylic resin is the most widely practiced technology at present. 3 layers of acrylic rubber
It has a layer or more layers, and has a spherical structure in which a hard layer containing MMA as a main component and a soft layer containing acrylate such as butyl acrylate as a main component are substantially alternately superposed, and particularly soft. Since the degree of cross-linking of the layer can be controlled by changing the addition amount of the polyfunctional cross-linking monomer,
The method is characterized in that the rubber particles are not deformed or destroyed by mechanical shearing force, which is a drawback of the method.

As described above, the second method is the most excellent method for improving the impact resistance of methacrylic resin in terms of performance, but since the rubber component has a multi-layer structure including a hard layer, the desired impact resistance is obtained. Higher productivity due to the fact that the addition amount of the rubber component required to obtain it becomes large and the productivity is poor due to the necessity of repeating multi-step polymerization to form a multilayer structure. Therefore, a technology for improving impact resistance of methacrylic resin that can be manufactured at low cost has been desired.

[0007]

A number of proposals have been made in order to impart impact resistance to methacrylic resins. However, any of the proposals has not yet found an impact resistance improving technique which has high productivity, can be manufactured at low cost, and maintains the original excellent characteristics of methacrylic resin.

The object of the present invention is to be more versatile industrially, and to impart surface gloss, rigidity, clear color tone, and also transparency of a molded product, and particularly excellent in weather resistance and impact resistance. To provide a methacrylic resin.

[0009]

The inventors of the present invention have high productivity, can be manufactured at low cost, and maintain the original excellent characteristics of methacrylic resin, and in particular, have improved weather resistance and impact resistance. As a result of extensive studies on the technology, a partially hydrogenated (hereinafter referred to as “partially hydrogenated”) polybutadiene was grafted with a monomer containing methyl methacrylate as a main component by an improved solution polymerization method. Polymerization, and after the polymerization is completed, heat treatment of the resulting polymer together with desolvation gives the target impact-resistant methacrylic resin, and the refractive index of partially hydrogenated polybutadiene can be adjusted by adjusting the hydrogenation rate of polybutadiene. It was found that it is also possible to make the methacrylic resin produced by polymerization and the refractive index of the methacrylic resin coincident with each other to give transparency, and thus completed the present invention.

That is, the present invention has a hydrogenation rate of 15 to 9
The copolymer is composed of 0% partially hydrogenated polybutadiene, 80 to 99.9% by weight of methyl methacrylate, and 0.1 to 20% by weight of another vinyl monomer copolymerizable with the methyl methacrylate. In impact-resistant methacrylic resin, the insoluble content of (a) when fractionated with acetone is 1 to
50 wt%, (b) Furthermore, when the acetone insoluble matter is fractionated with toluene, the insoluble matter is 70 to 100 wt%,
The impact-resistant methacrylic resin has a toluene swelling degree of 1 to 10.

The present invention will be described in detail below. The first feature of the present invention is to use partially hydrogenated polybutadiene as a rubber component. Stability of rubber itself against light,
That is, the weather resistance is improved as the hydrogenation rate is higher because it does not include double bonds derived from polybutadiene in the polymer chain, but on the other hand, the chemical reactivity is rapidly decreased with the increase of the hydrogenation rate. The reaction and the cross-linking reaction become difficult to proceed. Moreover, when the hydrogenation rate of polybutadiene is about 15% or more, it is soluble in aromatic vinyl monomers such as styrene, but hardly soluble or insoluble in methyl methacrylate, which is an essential monomer of the present invention. And
It becomes impossible to dissolve the raw material rubber in the monomer and continuously supply it to the polymerization reactor as is usually done with impact-resistant polystyrene.

The hydrogenation rate of polybutadiene is 15 to 90.
%, Preferably 50 to 80%, and if it is less than 15%, the impact resistance of the methacrylic resin will be poor, and if it exceeds 90%, the graft reactivity and the crosslinking reactivity will be significantly reduced. Hydrogenation is achieved by, for example, the method disclosed in Japanese Examined Patent Publication No. 5-20442, but is not limited to this method.

As another characteristic of polybutadiene, the vinyl bond content is preferably 10 to 80%, more preferably 30 to 60%. Vinyl bond content less than 10%,
Alternatively, if it exceeds 80%, the impact resistance of the impact-resistant methacrylic resin decreases, which is not preferable. The weight average molecular weight is 3
˜500,000 is preferable, and 50,000 to 300,000 is more preferable. If it is less than 30,000, the impact resistance will be deteriorated, while if it exceeds 500,000, the solution viscosity will be remarkably increased, and it will be extremely difficult to dissolve the raw rubber.

The structure of polybutadiene may be linear or branched. The second feature of the present invention is that the rubber particles are appropriately cross-linked and the surface of the particles is grafted with an appropriate amount of a methyl methacrylate copolymer, so that they are not deformed by shearing force during molding. , Good surface gloss, or transparency can be developed, and a suitable amount of polymethylmethacrylate is grafted on the surface of the rubber particles, and the compatibility between the rubber particles and polymethylmethacrylate is sufficiently high. That is, the rubber particles do not agglomerate or delaminate due to the shearing force, and the interface between the rubber particles and polymethylmethacrylate is stable by outdoor exposure, and cracks and impact resistance do not significantly decrease.

Although it is not practically easy to directly specify the degree of crosslinking and the graft ratio of the rubber particles, the amount of insoluble matter when fractionated with acetone and the insoluble matter and toluene swelling degree when fractionated with toluene are separated. It can be indirectly specified by and. Acetone insoluble content represents the amount of rubber particles in impact-resistant methacrylic resin (total of methyl methacrylate copolymer grafted with partially hydrogenated polybutadiene and methyl methacrylate copolymer trapped in the particles), and 1 weight If it is less than 50% by weight, the impact resistance is low, and if it exceeds 50% by weight, the rigidity is largely decreased and the processing fluidity is also significantly decreased. is there.

Further, the toluene insoluble content and the toluene swelling degree represent the degree of crosslinking of the rubber particles, and the toluene insoluble content is 70%.
If it is less than 10% by weight, the degree of crosslinking is insufficient and the desired effect is not exhibited. If the degree of toluene swelling exceeds 10, the degree of crosslinking of the rubber particles is insufficient and the weather resistance and the surface gloss of the molded article are reduced. On the contrary, if the degree of swelling is less than 1, the degree of crosslinking is excessive and the impact resistance is poor. Therefore, when the acetone-insoluble matter is separated with toluene, it is required to have 70 to 100% by weight and a toluene swelling degree of 1 to 10.

As described above, the impact-resistant methacrylic resin of the present invention is prepared by solution polymerization because partially hydrogenated polybutadiene is insoluble in methyl methacrylate, which is an essential monomer. It is necessary to select a polymerization condition that allows the reaction to proceed to a desired degree. As the polymerization solvent, an aromatic hydrocarbon having solubility in both partially hydrogenated polybutadiene and a copolymer containing methyl methacrylate as a main component, for example, benzene,
Toluene, xylene, ethylbenzene and the like are preferable.
As the amount of solvent increases, the partially hydrogenated polybutadiene can be more easily dissolved, and the viscosity of the polymerization system also decreases, which is advantageous for the polymerization operation.On the other hand, if the amount of solvent is too large, not only productivity decreases but also chain transfer reaction to the solvent occurs. It increases, and the graft reaction and the crosslinking reaction are hindered, which is not preferable. In the present invention, the preferred amount of solvent is in the range of 20 to 200% by weight based on the total amount of partially hydrogenated polybutadiene and the monomer.

The radical polymerization initiator has a half-life of 1
One of the organic peroxides having a temperature of 140 to 200 ° C. is used, or the temperature at which the half-life is 1 minute is 10
It is preferable to use an organic peroxide having a temperature of 0 to 160 ° C. and an organic peroxide having a temperature of 160 ° C. or higher in combination. As the organic peroxide having a half-life of 1 minute at 140 to 200 ° C., for example, 1,1-bis (t-butylperoxy) 3,
3,5-Trimethylcyclohexane, t-butylperoxylaurate, t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, dicumyl Examples thereof include peroxide, t-butyl cumyl peroxide, di-t-butyl peroxide and the like.

As the chain transfer agent, alkyl mercaptans are preferable, and polyfunctional alkyl mercaptans having two or more mercapto groups are particularly preferable in terms of crosslinking reaction. Examples of the alkyl mercaptan include n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, 1,4-butanedithiol, 1,6-hexanedithiol, ethylene glycol bisthioglycolate, ethylene glycol bisthiopropionate, butane. Diol bisthioglycolate, butanediol bisthiopropionate, hexanediol bisthioglycolate, hexanediol bisthiopropionate,
Examples thereof include trimethylolpropane tris- (β-thiopropionate) and pentaerythritol tetrakisthiopropionate.

The polymerization temperature is preferably in the range of 80 to 180 ° C. and raised in two or more stages along with the progress of the polymerization reaction. The polymerization reaction may be a batch type or a continuous type, but in the case of a batch type, the partially hydrogenated polybutadiene and the solvent are charged in a polymerization reactor, and the desired polymerization temperature is set after dissolution at an appropriate temperature. Radical polymerization initiator,
It is desirable to continuously add the monomer mixture in which the chain transfer agent and the like are dissolved to the polymerization reactor to carry out the polymerization reaction. In the case of the continuous type, one tank should dissolve partially hydrogenated polybutadiene in a solvent, the other tank should prepare a monomer mixture, and the mixture should be continuously fed at a constant ratio to carry out the polymerization reaction. Is desirable. In this case a radical polymerization initiator,
The chain transfer agent and the like may be put in one tank at a time, or may be put in pieces.

In the polymerization reaction, the final polymerization rate of the monomer is 80.
% Or more, more preferably 90% or more, and if the polymerization rate is lower than that, sufficient crosslinking reaction and graft reaction do not proceed, which is not preferable. Rubber particles are formed by the inversion of partially hydrogenated polybutadiene from the initial state in which it is dissolved in the solvent and monomer mixture, and when the polymerization reaction progresses and a certain amount of methyl methacrylate copolymer is produced, phase transition occurs. To be done. The particle diameter or structure of the rubber particles is determined by the stirring rotation speed and the viscosity of the polymerization system at this point. It may have a so-called salami structure in which the methyl methacrylate copolymer phase is multi-divided and included in the inside of the particle, or a single-phase core-shell structure. Rubber particle size is 0.05
It is preferably in the range of .about.1.0 micron. More preferably, it is in the range of 0.1 to 0.5 micron. If the particle size is smaller than 0.05 micron, impact resistance will decrease,
If it exceeds 1.0 micron, the surface gloss and rigidity are likely to decrease, which is not preferable. The structure of the rubber particles can be confirmed by a transmission electron microscope photograph taken by an ultrathin section method of impact-resistant methacrylic resin, and the weight average particle diameter is about 100 rubber particles in the transmission electron microscope photograph. The particle size was measured by the following formula.

Weight average particle size = Σn _i · D _i ⁴ / Σn _i · D _i ³ (where n _i is the number of rubber particles having a particle size D _i ) The impact-resistant methacrylic resin of the present invention is after the completion of the polymerization reaction. It can be obtained by removing the solvent and unreacted monomer by heating devolatilization, and the devolatilization temperature is 200 to 300 ° C., preferably 2
It is in the range of 20 to 270 ° C. If the temperature is 200 ° C or lower, the rubber particles are insufficiently crosslinked, and if the temperature exceeds 300 ° C, the polymer is thermally decomposed and colored, which is not preferable.

Other vinyl monomers copolymerizable with methyl methacrylate include methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid esters such as 2-ethylhexyl acrylate, ethyl methacrylate, butyl methacrylate, Methacrylic acid esters such as cyclohexyl methacrylate and t-butyl cyclohexyl methacrylate, aromatic vinyl such as styrene and p-methylstyrene, and acrylonitrile and methacrylonitrile,
Methacrylic acid and N-cyclohexylmaleimide can be exemplified.

The amount of vinyl monomer to be copolymerized is 0.1
In the range of up to 20% by weight, if less than 0.1% by weight, thermal decomposition is likely to occur during molding, and if it exceeds 20% by weight, the heat distortion temperature will be greatly lowered, which is not preferable. The weight average molecular weight of the methyl methacrylate copolymer is 5
˜300,000, more preferably 70 to 150,000.
The weight average molecular weight can be obtained by measuring the soluble content of the impact-resistant methacrylic resin separated by acetone with gel permeation chromatography. It is a value in terms of polystyrene.

Antioxidants, ultraviolet absorbers, lubricants, release agents, antistatic agents, flame retardants, dyes and pigments can be added to the impact-resistant methacrylic resin of the present invention as required. The impact-resistant methacrylic resin thus obtained is injection-molded or extrusion-molded to provide excellent weather resistance, surface gloss, rigidity, and clear color tone, and improved impact resistance and solvent resistance. Goods can be manufactured.

[0026]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The measurements in Examples and Comparative Examples were carried out using the following methods or measuring instruments.・ Melt flow index: ASTMD1238 ・ Haze: ASTMD1003 ・ Izod impact strength (with notch): ASTMD25
6-Weight average particle diameter: A sample cut from a pellet is stained with osmium tetroxide to prepare an ultrathin section, and a transmission electron microscope photograph is taken (100,000 times). The diameter of 100 randomly selected rubber particles was measured, and the weight average particle diameter was calculated by the following formula.

Weight average particle size = Σn _i · D _i ⁴ / Σn _i · D _i ³ (where n _i is the number of rubber particles having a particle size D _i ) Acetone fractionation: About 1 g of pellets is precisely weighed (W ₁ ) Add 20 ml of acetone, shake at 25 ° C. for 5 hours, and then centrifuge at 5 ° C. and 23000 rpm for 45 minutes.
After removing the supernatant by decantation, 20 ml of acetone is newly added and shaken at 25 ° C. for 1 hour. After shaking, centrifuge at 5 ° C. and 23000 rpm for 45 minutes. Decant and remove this supernatant,
After vacuum drying at 100 ° C. for 2 hours and cooling to room temperature in a desiccator, the weight of the residue is weighed (W ₂ ). The insoluble content (% by weight) of the acetone fractionation is calculated by the following formula.

Insoluble matter in acetone fractionation = (W ₂ / W ₁ ) × 100 Toluene fractionation: About 0.5 g of the insoluble matter obtained in the acetone fractionation was precisely weighed (W ₃ ), and 20 ml of toluene was added at 25 ° C. After shaking for 5 hours, 5 ℃, 23000rpm
Centrifuge for 45 minutes at. After removing the supernatant liquid by decantation, 20 ml of toluene is newly added and shaken at 25 ° C. for 1 hour. After shaking, 5 ℃, 2300
Centrifuge for 45 minutes at 0 rpm. The supernatant is decanted off and the weight of the residue containing toluene is weighed (W ₅ ). Then, it is vacuum dried at 100 ° C. for 2 hours, cooled to room temperature in a desiccator, and the weight of the residue is weighed (W ₄ ). The insoluble content (% by weight) of the toluene fraction is calculated by the following formula.

Insoluble matter in toluene fractionation = (W ₄ / W ₃ ) × 100 Toluene swelling degree: In the above toluene fractionation, the toluene swelling degree is calculated by the following formula. Toluene swelling degree = W ₅ / W ₄ · Hydrogenation rate: Polybutadiene before hydrogenation was used as a heavy chloroform solution, and chemical shift was 4.7 to 5.2 ppm (signal C ₀ ) in FT-NMR (270 mega). From the integrated intensity of 1,2-vinyl proton (= CH ₂ ) and vinyl proton (= CH-) having a chemical shift of 5.2 to 5.8 ppm (signal D ₀ ) Calculate%

V = [(C _0/2 ) / {C _0/2 + (D _{0
-C 0/2) / 2}} ] × 100 further partially hydrogenated polybutadiene and heavy chloroform solution, as in FT-NMR chemical shifts 0.6~1.0p
Hydrogenated pm (designated as signal A ₁ ) hydrogenated methyl group proton (—CH ₃ ) due to 2 bond, non-hydrogenated chemical shift of 4.7 to 5.2 ppm (designated as signal C ₁ ) 1 , Proton by 2-vinyl (= CH
₂ ), chemical shift of 5.2 to 5.8 ppm (signal D ₁
Of the non-hydrogenated vinyl protons (= C
Each hydrogenation rate is calculated from the integrated intensity of H-) by the following formula.

_{Firstly, p = (C 0/2} ) / (C 1/2 + A 1/3) A 11 = pA 1, C 11 = pC 1, D 11 = pD 1 1,2- vinyl bond portion of the hydrogenated Rate B% B = [(A _11/3 ) / (A _11/3 + C _11/2 )] × 10
0 1,4 double bond moiety of the hydrogenation ratio C% C = [{(D 0 -C 0/2) / 2- (D 11 -C 11/2)
_{/ 2} / (D 0 -C} 0/2) / 2] × 100 polybutadiene overall hydrogenation rate A% A = (V × B + (100-V) × C) / 100 · bound styrene content styrene - butadiene Chloroform solution was used as the polymer, and U was caused by the phenyl nucleus of styrene.
The amount of bound styrene (% by weight) was measured by absorption at V254 nm.

Synthesis of polybutadiene and partially hydrogenated polybutadiene: A butadiene / n-hexane solution (butadiene concentration 30% by weight) was used for 8.7 hours per hour by using a jacketed autoclave with an internal volume of 10 liters equipped with a stirrer as a polymerization machine. N-butyllithium / n at a rate of liter
-Hexane solution (concentration 0.2% by weight) at a rate of 1.8 liters per hour, N, N, N ', N'-tetramethylethylenediamine / n-hexane solution (concentration 0.14% by weight) every time. Feeding was carried out at a rate of 3.9 liters for continuous polymerization of butadiene at a polymerization temperature of 90 ° C. The obtained active polymer was continuously fed to the same second-stage reactor, and a silicon tetrachloride / n-hexane solution (concentration 0.15% by weight) was added in an amount of 2.0 liters per hour (equivalent to lithium). At a rate of (mol) to perform the coupling reaction. Further, by continuously feeding the solution to the reactor of the third stage and continuously feeding di-p-tolylbis (1-cyclopentadienyl) titanium / cyclohexane solution as a hydrogenation catalyst and hydrogen,
The hydrogenation reaction was carried out at 80 ° C.

2,6-di-t-butylhydroxytoluene was added to the resulting partially hydrogenated polymer solution as an antioxidant in an amount of 0.1.
5 parts by weight (per polymer) was added and the solvent was removed.
Partially hydrogenated polybutadiene (H-1) having a hydrogenation rate of 30%, partially hydrogenated polybutadiene (H-2) having a hydrogenation rate of 48% by adjusting the hydrogenation catalyst and the hydrogen supply amount,
Partially hydrogenated polybutadiene (H-
3), partially hydrogenated polybutadiene with a hydrogenation rate of 92% (H
-4) was synthesized. In addition, polybutadiene (H-0) was also synthesized by not performing the hydrogenation reaction. The analytical values of this polybutadiene H-0 are as follows.

1,2-Vinyl bond content 48% 1,4-bond content 52%

[0035]

Example 1 After replacing the inside of a rubber dissolution tank having an internal volume of 40 liters with nitrogen, 20 kg of toluene, 2.9 kg of partially hydrogenated polybutadiene (H-1) having a hydrogenation rate of 30%, 1,1
-Bis (t-butylperoxy) 3,3,5-trimethylcyclohexane (hereinafter referred to as catalyst P-1) 10
g, 50 g of trimethylolpropane tris- (β-thiopropionate) (hereinafter, abbreviated as TMTP) were charged, stirred and dissolved at 50 ° C. to prepare a rubber solution. On the other hand, after replacing the inside of the monomer mixing tank having an internal volume of 30 liters with nitrogen, 23.4 kg of methyl methacrylate (hereinafter abbreviated as MMA), 0.6 kg of methyl acrylate (hereinafter abbreviated as MA), 34 g of di-t-butyl peroxide (hereinafter abbreviated as catalyst P-2) was charged and stirred and dissolved at 10 ° C. to prepare a monomer mixture liquid.

The rubber solution and the monomer mixed solution thus prepared were continuously fed to a mixing tank having an internal volume of 0.2 liter, and subsequently, two laminar flow type internal volumes having an internal volume of 4 liters were connected in series. Polymerization was performed with a polymerization machine. The rubber solution is 0.
At a rate of 64 liters, and the monomer mixture is 0.
The solution was delivered at a rate of 69 liters. The internal temperature of the first-stage mixing tank was maintained at 100 ° C., and the stirring number was 500 rpm.
In the second stage laminar flow polymerization machine, maintain the internal temperature at 120 ° C,
The stirring number was 200 rpm. The internal temperature of the laminar flow type polymerization machine in the third stage was 150 ° C., and the stirring number was set to 50 rpm.

The devolatilizer connected to the third stage laminar flow type polymerizer was used to remove the solvent and the residual monomer to obtain pellets of the impact-resistant methacrylic resin S-1. The polymerization rate of the monomer was calculated by comparing the feed amount of the raw material per hour with the weight of the obtained pellet, and it was 93%.
Met. The pellets had an acetone insoluble content of 34% by weight, a toluene insoluble content of 98% by weight, and a toluene swelling degree of 5.8. The weight average particle diameter was 0.32 micron.

Further, a predetermined test piece was prepared by injection molding and its physical properties were measured, and the following test results were obtained. Melt flow index 1.7 g / 10 minutes Izod impact strength 6.9 kg · cm / cm

[0039]

Example 2 Polymerization and impact resistance were conducted in the same manner as in Example 1 except that the rubber solution was fed at a rate of 0.48 liters per hour and the monomer mixture was delivered at a rate of 0.52 liters per hour. A pellet of the methacrylic resin S-2 was obtained. Polymerization rate is 98%
Then, the acetone insoluble matter is 35% by weight, and the toluene insoluble matter is 9%.
9% by weight, the degree of toluene swelling was 5.4, and the weight average particle diameter was 0.34 micron.

A predetermined test piece was prepared from this pellet by injection molding, and its physical properties were measured. The following test results were obtained. Melt flow index 1.6 g / 10 min Izod impact strength 7.4 kgcm / cm

[0041]

Example 3 Polymerization and impact resistance were conducted in the same manner as in Example 1 except that the rubber solution was fed at a rate of 0.96 liters per hour and the monomer mixture was fed at a rate of 1.04 liters per hour. Pellets of methacrylic resin S-3 were obtained. The polymerization rate is 76%,
Acetone insoluble matter is 30% by weight, toluene insoluble matter is 73% by weight, toluene swelling degree is 8.4, and weight average particle diameter is 0.
It was 24 microns.

A predetermined test piece was prepared from this pellet by injection molding, and its physical properties were measured. The following test results were obtained. Melt flow index 1.8 g / 10 minutes Izod impact strength 5.2 kg · cm / cm

[0043]

Example 4 The following polymerization was carried out using the same polymerization apparatus as in Example 1. Toluene 20 kg, partially hydrogenated polybutadiene (H-1) 4.3 kg, catalyst (P-1) 10 g, T
A rubber solution was prepared by charging 40 g of MTP into a rubber dissolution tank. A monomer mixture having the same composition as in Example 1 was prepared in the monomer mixing tank.

The rubber solution was fed to the first-stage mixing tank at a rate of 0.68 liters per hour, and the monomer mixture was fed to the first-stage mixing tank at a rate of 0.65 liters per hour. The temperature and the number of agitation were 100 ° C. and 50 in the first-stage mixing tank as in Example 1.
0 rpm, the second stage laminar flow type polymerization machine is 120 ° C and 200
rpm, 150 ° C. and 50 rp for the third stage laminar flow polymerization machine
set to m.

The solvent and the residual monomer were removed with a devolatilizer to obtain pellets of the impact-resistant methacrylic resin S-4. The polymerization rate was 90%. The pellets had an acetone insoluble content of 29% by weight, a toluene insoluble content of 78% by weight, and a toluene swelling degree of 8.1. The weight average particle diameter was 0.22 micron. When a predetermined test piece was prepared by injection molding and its physical properties were measured, the following test results were obtained.

Melt flow index 1.3 g / 10 minutes Izod impact strength 6.6 kg · cm / cm

[0047]

Example 5 The following polymerization was carried out using the same polymerization apparatus as in Example 1. Toluene 25 kg, partially hydrogenated polybutadiene (H-1) 2.5 kg, catalyst (P-1) 10 g, T
A rubber solution was prepared by charging 120 g of MTP in a rubber dissolving tank. A monomer mixture having the same composition as in Example 1 was prepared in the monomer mixing tank.

The rubber solution was fed to the first-stage mixing tank at a rate of 0.46 liters per hour, and the monomer mixture was fed at a rate of 0.87 liters per hour. The temperature and the stirring number were set to the same values as in Example 1. The solvent and the residual monomer were removed by a devolatilizer to obtain pellets of the impact-resistant methacrylic resin S-5. The polymerization rate was 97%. The pellets had an acetone insoluble content of 21% by weight, a toluene insoluble content of 99% by weight, and a toluene swelling degree of 4.0.
The weight average particle diameter was 0.36 micron.

A predetermined test piece was prepared by injection molding,
When the physical properties were measured, the following test results were obtained. Melt flow index 1.9 g / 10 minutes Izod impact strength 3.5 kg · cm / cm

[0050]

Example 6 The following polymerization was carried out using the same polymerization apparatus as in Example 1. Toluene 25 kg, partially hydrogenated polybutadiene (H-1) 1.6 kg, catalyst (P-1) 8 g, TM
A rubber solution was prepared by charging 30 g of TP into a rubber dissolution tank. A monomer mixture having the same composition as in Example 1 was prepared in the monomer mixing tank.

The rubber solution was fed to the first-stage mixing tank at a rate of 0.87 liter per hour, and the monomer mixture was fed to the first-stage mixing tank at a rate of 0.46 liter per hour. The temperature and the stirring number were set to the same values as in Example 1. The solvent and the residual monomer were removed with a devolatilizer to obtain pellets of the impact-resistant methacrylic resin S-6. The polymerization rate was 94%. The acetone insoluble content of the pellets was 43% by weight, the toluene insoluble content was 75% by weight, and the toluene swelling degree was 7.4.
The weight average particle diameter was 0.47 micron.

A predetermined test piece was prepared by injection molding,
When the physical properties were measured, the following test results were obtained. Melt flow index 2.1 g / 10 minutes Izod impact strength 5.6 kgcm / cm

[0053]

Example 7 Polymerization was carried out under the same polymerization conditions as in Example 1 except that partially hydrogenated polybutadiene H-2 having a hydrogenation rate of 48% was used instead of partially hydrogenated polybutadiene H-1 to obtain impact-resistant methacrylic acid. Resin S-7 was obtained. Polymerization rate is 92%
Then, the acetone insoluble matter is 29% by weight, and the toluene insoluble matter is 9% by weight.
4% by weight and the degree of swelling with toluene were 6.2. The weight average particle diameter was 0.27 micron.

A predetermined test piece was prepared by injection molding,
When the physical properties were measured, the following test results were obtained. Melt flow index 1.6 g / 10 minutes Izod impact strength 6.4 kgcm / cm

[0055]

Example 8 Polymerization was carried out under the same polymerization conditions as in Example 1 except that partially hydrogenated polybutadiene H-3 having a hydrogenation rate of 75% was used instead of partially hydrogenated polybutadiene H-1 to obtain impact-resistant methacrylic acid. Resin S-8 was obtained. Polymerization rate is 93%
28% by weight of acetone insoluble matter and 9% of toluene insoluble matter.
2% by weight and the degree of swelling of toluene were 6.9. The weight average particle diameter was 0.25 micron.

A predetermined test piece was prepared by injection molding,
When the physical properties were measured, the following test results were obtained. Melt flow index 1.6 g / 10 minutes Izod impact strength 6.2 kgcm / cm Haze 1.8%

[0057]

Example 9 The stirring number of the second-stage laminar flow polymerization machine was 300
Polymerization was performed under the same polymerization conditions as in Example 8 except that the rpm was changed to obtain impact-resistant methacrylic resin S-9. The polymerization rate was 92%, the acetone insoluble content was 27% by weight, the toluene insoluble content was 93% by weight, the toluene swelling degree was 6.8, and the weight average particle diameter was 0.19 micron.

A predetermined test piece was prepared by injection molding,
When the physical properties were measured, the following test results were obtained. Melt flow index 1.6 g / 10 min Izod impact strength 5.1 kgcm / cm Haze 1.2%

[0059]

[Example 10] The stirring number of the second-stage laminar flow type polymerization machine was changed to 15
Polymerization was performed under the same polymerization conditions as in Example 8 except that the rotation speed was 0 rpm to obtain impact-resistant methacrylic resin S-10. The polymerization rate was 91%. The acetone insoluble matter was 30% by weight, the toluene insoluble matter was 89% by weight, the toluene swelling degree was 7.1, and the weight average particle diameter was 0.32 micron.
When a predetermined test piece was prepared by injection molding and its physical properties were measured, the following test results were obtained.

Melt flow index 1.5 g / 10 minutes Izod impact strength 6.5 kg · cm / cm haze 2.9%

[0061]

Comparative Example 1 Polymerization was conducted under the same polymerization conditions as in Example 1 except that partially hydrogenated polybutadiene H-4 having a hydrogenation rate of 92% was used instead of partially hydrogenated polybutadiene H-1.
Impact resistant methacrylic resin S-11 was obtained. Polymerization rate is 87
%, The acetone insoluble content was 18% by weight, the toluene insoluble content was 41% by weight, the toluene swelling degree was 16.6, and the weight average particle diameter was 0.15 micron.

A predetermined test piece was prepared by injection molding,
When the physical properties were measured, the following test results were obtained. Melt flow index 1.9 g / 10 minutes Izod impact strength 1.4 kgcm / cm

[0063]

Comparative Example 2 Instead of partially hydrogenated polybutadiene H-1, commercially available hydrogenated block copolymer Kraton G-1650.
Polymerization was performed under the same polymerization conditions as in Example 1 except that (Shell Chemical Co.) was used, and the impact-resistant methacrylic resin S- was used.
I got 12. The polymerization rate was 88%. The acetone insoluble content was 36% by weight, the toluene insoluble content was 8.8% by weight, and the toluene swelling degree was 15.2. The weight average particle diameter was 0.39 micron. In the measurement of the particle size, ruthenium tetroxide was used for dyeing.

A predetermined test piece is prepared by injection molding,
When the physical properties were measured, the following test results were obtained. Melt flow index 1.8 g / 10 minutes Izod impact strength 4.7 kg · cm / cm Furthermore, based on JISA1415, a Sunshine weather meter (hereinafter abbreviated as SWOM) manufactured by Suga Test Machine Co., Ltd. When carbon was used and the test piece was exposed for 1000 hours, the yellowing degree (J
(Measured according to ISK7103) was 0.9. At the same time, the test piece of Example 1 was exposed for 1000 hours, the yellowing degree measured was 0.2, and it could be visually judged that the test piece of Comparative Example 2 was more colored.

[0065]

[Comparative Example 3] The inside of a monomer mixing tank having an internal volume of 30 liter was replaced with nitrogen, and then 4 kg of toluene and polybutadiene (H
-0) 1 kg, methyl methacrylate 14.6 kg, methyl acrylate 0.4 kg, catalyst (P-1) 6 g, catalyst (P-2) 4 g, t-dodecyl mercaptan 20 g were charged and dissolved at 10 ° C with stirring. .

The thus prepared solution was continuously fed at a rate of 1.33 liters per hour to two laminar flow type polymerization machines having an internal volume of 4 liters connected in series to carry out polymerization.
The internal temperature of the first-stage polymerization machine was 130 ° C, and the stirring number was 20
It was set to 0 rpm. The internal temperature of the third-stage polymerization machine is 150
C. and the stirring number was 50 rpm. A devolatilizer connected to the second-stage laminar flow polymerization machine was used to remove the solvent and the residual monomer to obtain pellets of the impact-resistant methacrylic resin S-13. The polymerization rate was 93%, the acetone insoluble content was 31% by weight, the toluene insoluble content was 96% by weight, the toluene swelling degree was 8.2, and the weight average particle diameter was 0.63 micron.

A predetermined test piece was prepared by injection molding,
When the physical properties were measured, the following test results were obtained. Melt flow index 1.9 g / 10 minutes Izod impact strength 9.4 kg · cm / cm Further, a test piece for measuring Izod impact strength is JIS A1.
3. Based on 415, the Izod impact strength was measured after the test piece was exposed for 1000 hours using a sunshine weatherometer (hereinafter abbreviated as SWOM) manufactured by Suga Test Instruments, using sunshine super long life carbon. It decreased to 3 kg · cm / cm (retention rate after exposure = 46% relative to the value before exposure). At the same time, the test pieces of Example 1 and Example 8 were exposed for 1000 hours, and the measured Izod impact strengths were each 6.1 kg · cm / cm.
(Retention rate = 89%) and 5.8 kg · cm / cm (retention rate = 94%), both of which were superior to the test results of Comparative Example 3.

[0068]

INDUSTRIAL APPLICABILITY The impact-resistant methacrylic resin of the present invention is industrially more versatile and has improved impact resistance and solvent resistance in addition to the excellent weather resistance and appearance which are characteristic features of methacrylic resin. Therefore, it can be widely used for indoor and outdoor applications.

Claims (1)

[Claims] 1. A partially hydrogenated polybutadiene having a hydrogenation rate of 15 to 90% and methyl methacrylate 80 to 99.9.
In an impact-resistant methacrylic resin composed of a copolymer composed of 0.1% to 20% by weight of another vinyl monomer copolymerizable with the methyl methacrylate, (a) when fractionated with acetone. Insoluble content is 1 to 50% by weight,
(B) An impact-resistant methacrylic resin characterized by having an acetone-insoluble content of 70 to 100% by weight and a toluene swelling degree of 1 to 10 when the acetone-insoluble content is separated with toluene.