JP2967015B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent thermoplastic resin composition having excellent flexibility, processability and weather resistance.

[0002]

2. Description of the Related Art Polyolefin-based resins and polyolefin-based elastomers can be molded singly or as a composition containing other thermoplastic elastomers, softeners, etc., taking advantage of their flexibility and extrudability. Has been used in materials. For example, molding materials such as bumpers for automobiles and console panel surfaces are known.Both polyolefin-based resins and polyolefin-based elastomers do not have polar groups, so they are paintable, printable, and colored when colored. And it is difficult to select the type of color when processing. In addition, these polyolefin resins and elastomers have problems such as low surface hardness contrary to flexibility and poor scratch resistance. However, due to recent increasing interest in environmental issues, recyclable materials have come to the spotlight, and studies on the improvement of polyolefin polymers have been earnestly studied.

On the other hand, acrylic resins have been used as various molding materials by taking advantage of their characteristics such as transparency, coloring (coloring), weather resistance, and surface hardness. This resin is often used outdoors, taking advantage of its excellent colorability and weather resistance, and is also used for transparent materials such as window glasses and fluorescent lamp covers. Since this resin has a property of being decomposed into a monomer when heated, it has been studied as a recyclable material. However, acrylic resins generally have poor flexibility and low impact strength, and many studies have been made to improve flexibility.

[0004] Resins having both of these features to some extent include ABS resins and impact-resistant acrylic resins, but ABS resins are inferior in transparency, and both resins have good impact resistance. It is known that the rubber component exerting an influence has a chemically unstable double bond in its main chain, resulting in poor weather resistance. In order to satisfy the weather resistance of the acrylic resin, it has been studied to disperse an AES resin or an acrylate-based rubber in the resin, but the use of the resin is limited due to a balance between physical properties and cost. .

[0005] Further, polyvinyl chloride resins are inexpensive and therefore are used for a wide range of applications along with polyolefin resins. Since the hardness and mechanical properties of this resin can be controlled by the amount of the plasticizer, low hardness and flexibility that compete with polyolefins are required in applications where hardness and transparency are required to compete with acrylic resins. It has been used in a variety of application fields, and has exhibited advantages due to its low cost. However, the polyvinyl chloride resin inherently has poor processability, and thus requires a large amount of plasticizer, and has a problem that the plasticizer precipitates on the surface due to aging (bleed out). In addition, this resin generates a toxic halogen-containing decomposition product by thermal decomposition, and it is practically difficult to recycle the resin.

[0006] If an acrylic resin and a polyolefin elastomer can be compounded, the flexibility of the polyolefin elastomer can be further improved while maintaining the surface properties such as surface hardness of the acrylic resin, weather resistance and color development. Properties such as processability and low-temperature properties can be imparted, and a safe and recyclable material should be obtained. However, the miscibility between the polyolefin-based elastomer and the acrylic resin is poor, and the occurrence of delamination, devitrification, and a decrease in mechanical strength cannot be avoided, and satisfactory results have not been obtained.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to improve the miscibility of a polyolefin-based elastomer and an acrylic resin, thereby improving the surface properties such as surface hardness of the acrylic resin, weather resistance, and transparency. It is an object of the present invention to provide a novel acrylic thermoplastic resin composition that retains the above properties and has the properties of a polyolefin elastomer such as flexibility and low-temperature characteristics.

[0008]

As a result of the study of the present inventors, the above-mentioned problem has been solved by using an acrylic resin having a specific intrinsic viscosity, and a polymer block comprising an aromatic vinyl compound as a polyolefin elastomer, It has been found that this problem is solved by using a thermoplastic block copolymer having a polymer block comprising a specific conjugated diene.

That is, according to the present invention, a polymer block (a) consisting of 10 to 90 parts by weight of an acrylic resin (A) containing methyl methacrylate as a main component and an aromatic vinyl compound, isoprene or a copolymer of isoprene and butadiene is used.
In a thermoplastic resin composition containing 90 to 10 parts by weight of a hydrogenated product (B) of a block copolymer having a polymer block (b) composed of a mixture, the acrylic resin (A) has (1) 70 to 100% by weight of methyl methacrylate, 0 to 30% by weight of at least one alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, and 0 to 20 of other ethylenically unsaturated compounds copolymerizable therewith. (2) having an intrinsic viscosity of 0.1 to 0.35 dl / g measured in chloroform at 20 ° C., and a hydrogenated product (B) of a block copolymer (hereinafter referred to as a saturated thermoplastic elastomer). (1) The number average molecular weight of each polymer block (a) in the hydrogenated product (B) of the block copolymer is 3000 to 3000
(2) the total content of the polymer block (a) in the hydrogenated product (B) of the block copolymer is 10 to 60% by weight; and (3) the isoprene in the polymer block (b). (4) The hydrogenated product (B) of the block copolymer has a number average molecular weight of 30,000 to 300,000, and the weight ratio of butadiene to butadiene is 40/60 or more and 100/0 or less. and weather resistance, the thermoplastic resin composition that having a transparency not only excellent in surface properties is provided.

Hereinafter, the present invention will be described in detail.

The acrylic resin (A) used in the present invention must contain at least 70% by weight of methyl methacrylate, thereby providing mechanical strength, heat resistance, weather resistance, coloring, and coloring. And the like are good.

In such an acrylic resin, at least one alkyl acrylate having an alkyl group having 1 to 8 carbon atoms is used in an amount of 0 to 30% by weight, and specific examples thereof include methyl acrylate. , Ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and the like.

The other ethylenically unsaturated compounds copolymerizable therewith are used in an amount in the range of 0 to 20% by weight, and specific examples thereof include methacrylic acid, metal methacrylate, ethyl methacrylate, and n-methacrylic acid. -Butyl, s-butyl methacrylate, t-butyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, methacrylate compounds such as cyclohexyl methacrylate, vinyl ester compounds such as vinyl acetate, styrene, α-methylstyrene Aromatic vinyl compounds such as
Maleic anhydride, maleic acid mono- and dialkyl esters, maleimide-based compounds such as N-phenylmaleimide and the like can be mentioned. One or more of these compounds can be used in any combination in any ratio.

Acrylic resin (A) used in the present invention
Has an intrinsic viscosity of 0.1 when measured in chloroform at 20 ° C.
It is necessary in the range of ~0.35dl / g. A
The intrinsic viscosity of the cryl resin (A) is 0. strength is smaller than ldl / g, weatherability and heat resistance are compromise its not desired resin composition is obtained. Also , acrylic resin
When the intrinsic viscosity of (A) is greater than 0.35 dl / g, the miscibility of the resins with each other is reduced, and as a result, surface roughening and delamination are likely to occur, and a desired good molded product is stabilized. I can't get it.

The acrylic resin (A) can be produced by a general polymerization technique such as solution polymerization, emulsion polymerization, suspension polymerization and the like, and the production method is not particularly limited.

The hydrogenated product of the block copolymer used as component (B) in the present invention includes a polymer block of an aromatic vinyl compound (a), isoprene homopolymer or isoprene and butadiene copolymer Partially or completely hydrogenated, it is a heavy hydrogenated product of isoprene and butadiene.
And a polymer block (b) having a quantitative ratio in the range of 40/60 to 100/0.

The aromatic vinyl compound used here is:
Styrene, α-methylstyrene, etc., which can be used alone or in combination of two or more. The polymer block (a) in the component (B) needs to have a number average molecular weight in the range of 3,000 to 30,000, and the polymer block (a) has a total weight with the polymer block (b). Should be in the range of 10 to 60% by weight.

[0018] Although not limited in a strict sense the shape of the block copolymer constituting the component (B), in general, a polymer block comprising an aromatic vinyl compound
a , when a polymer block composed of a conjugated diene is represented by b ,
(Ab) n, (ab) na, (ba) na
The shape of [n is an integer of 1 or more] is preferable.
Those having the shape of -ba are more preferably used in view of workability at the time of mixing with the acrylic resin and performance of the obtained resin.

The weight ratio of isoprene to butadiene (isoprene / butadiene) in the polymer block (b) is 4
0/60 to 100/0, more preferably 50/50 to 1
It is necessary to be within the range of 00/0, and the primary structure of the molecular chain may have any of a random structure and a block structure.

In the present invention, the component (B) needs to have the unsaturated double bond of the block (b) constituting the component (B) hydrogenated, and in consideration of heat resistance and weather resistance, the hydrogenation ratio is 70%.
% Is preferable.

The hydrogenated product (B) of the block copolymer satisfying the above requirements further has a number average molecular weight of 30,000 to 3
It is necessary to be in the range of 00000, so that the hydrogenated product of the block copolymer exhibits thermoplastic properties and has good miscibility with the acrylic resin.

In the production of the hydrogenated product of the block copolymer of the component (B) used in the present invention, a polymer is obtained by anionic living polymerization using an organic alkali metal initiator, which is usually performed, and then hydrogenated. It can be done by doing For example, n-butyllithium, hexane using an anionic polymerization initiator such as s-butyllithium, heptane, saturated aliphatic hydrocarbon compounds such as cyclohexane,
Alternatively, an aromatic vinyl compound and a conjugated diene-based monomer such as isoprene and butadiene are successively introduced into the system at a temperature of 30 to 60 ° C. using an aromatic hydrocarbon compound such as benzene, toluene, and xylene as a solvent. A method of obtaining a block copolymer by adding and polymerizing, or a method of living a binary block copolymer by polymerizing an aromatic vinyl compound and a conjugated diene such as isoprene and butadiene under the same conditions as described above. Manufacture polymers,
An example is a method obtained by subjecting this to a coupling treatment with a dihalogen compound such as 1,2-dibromoethane, 1,4-dibromobutane, and 1,4-dichlorobenzene.

The obtained block copolymer is hydrogenated by a conventional method to form a hydrogenated product. As the hydrogenation catalyst, a homogeneous catalyst or a heterogeneous catalyst can be used. As the homogeneous catalyst, an organic transition metal catalyst (for example, nickel acetylacetonate, cobalt acetylacetonate, nickel naphthenate, cobalt naphthenate, etc.)
Ziegler catalysts and the like are used in combination with alkylated products of metals such as aluminum, alkali metals and alkaline earth metals. These are used in an amount of 0.01 to 0. It is used in an amount of about 1 mol %. In this case, the hydrogenation reaction is carried out under a hydrogen pressure of normal temperature to 150 ° C. and normal pressure to 50 kg / cm ² ,
End in time. After the reaction is completed, acidic water is added to the vessel, and the mixture is vigorously stirred to dissolve the hydrogenation catalyst in water. The aqueous phase of the two phases that have been phase-separated is removed, and the solvent is distilled off to obtain the desired hydrogenated product of the block copolymer.

As the heterogeneous catalyst, a metal catalyst such as nickel, cobalt, palladium, rhodium, ruthenium, platinum or the like may be used alone or a metal compound such as silica,
It is supported on diatomaceous earth, alumina, activated carbon and the like, and its amount is suitably 0.5 to 10% by weight based on the weight of the block polymer. Hydrogenation reaction is normal temperature to 250 ° C, normal pressure to 2
It is performed under a hydrogen pressure of 00 kg / cm ² and is completed in about 1 to 50 hours. After completion of the reaction, the reaction product is taken out of the vessel, the catalyst is separated by filtration, and the solvent is distilled off from the obtained filtrate to obtain the desired hydrogenated product of the block copolymer.

In the present invention, the components (A) and (B) are mixed and used in a weight ratio in the range of 10/90 to 90/10, whereby not only flexibility is enhanced but also processability and weather resistance are improved. And a thermoplastic resin composition having excellent transparency can be obtained. Further, when higher weather resistance is required for the composition, it is preferable to use the component (A) and the component (B) in a weight ratio in the range of 25/75 to 90/10.

The thermoplastic resin composition of the present invention comprises a reinforcing agent,
Various additives such as fillers and pigments can be optionally contained. For example, reinforcing agents such as carbon black, mica, glass fiber and carbon fiber, fillers such as alumina, talc, zeolite, ferrite, calcium carbonate and aluminum hydroxide, dyes, pigments, flame retardants, ultraviolet rays Organic or inorganic additives used as absorbents and other functional additives. The amount of addition is within the range of commonly used amounts. For example, 0.001 to 50 parts by weight, or more in some cases, can be used based on 100 parts by weight of the whole resin composition. Further, the thermoplastic resin composition of the present invention can contain, if desired, polyolefins such as polyethylene and polypropylene, and olefin plasticizers such as polybutene, polyisobutylene, and process oil within a range that does not impair the physical properties.

The mixing method for obtaining the desired composition can be performed by a conventional and conventional method, and the method is not particularly limited. For example, it can be carried out by a method of mixing in a molten state using a conventional melt kneader such as an extruder or a kneader.
At this time, the components (A) and (B) may be simultaneously melt-kneaded, or the remaining components may be added and melt-kneaded with one of the components in advance by arbitrary selection. Good. At that time, it is necessary to knead at a temperature higher than the temperature at which each raw material resin melts and flows, and at a temperature within a range that does not cause deterioration.
Although it is in the range of 00 ° C., a more preferable temperature is 180 to 28.
Performed at 0 ° C.

[0028]

Next, the present invention will be described specifically with reference to examples. In addition, the part in each Example represents a weight part. Each physical property was determined by the following method. (1) Intrinsic viscosity: Dissolve an acrylic resin at a certain concentration in chloroform, and use an automatic viscometer (Fica, France) at 20 ° C.
Manufactured by the company). (2) Tensile property test: Measured in accordance with JIS K-7113
Specified. That is, the dumbbell 2 formed by injection molding
No. was measured using a test piece. (3) Hardness: ASTM D-2240 or JISK-
It was measured according to 6301. (4) Pencil abrasion: The abrasion was evaluated using a method and an apparatus according to JIS K-5400. (5) Total light transmittance: calculated from the absorption spectrum of visible light. (6) dispersion state: cutaway cooled specimens in liquids in nitrogen, observing the fractured surface by scanning electron microscope, were evaluated by measuring the average particle diameter of the dispersed particles.

[0029] Incidentally, the acrylic resin used in this embodiment,
And the hydrogenated product of the block copolymer was produced as follows.

Production Method of Acrylic Resin (1) 500 parts of pure water is charged into a polymerization vessel equipped with a reflux condenser, and then 425 parts of methyl methacrylate and 55 parts of methyl acrylate
, 2.5 parts of lauryl peroxide and 4 parts of lauryl mercaptan were charged, the atmosphere was replaced with nitrogen while stirring, and the temperature was raised to 80 ° C for 2 hours, and then 9 hours.
Polymerization was carried out at 5 ° C. for 1 hour, washed with water and dried to obtain a bead-like polymer. The intrinsic viscosity of the bead polymer measured in chloroform at 20 ° C. was 0.283 dl / g.

Production method of acrylic resin (2) 500 parts of pure water is charged into a polymerization vessel equipped with a reflux condenser, and then 460 parts of methyl methacrylate and 40 parts of methyl acrylate are added.
, 2.5 parts of lauryl peroxide and 3.5 parts of lauryl mercaptan were charged, the atmosphere was replaced with nitrogen while stirring, and the temperature was raised to 80 ° C. for 2.5 hours and then at 95 ° C. for 1 hour. Polymerization was carried out for an hour, followed by washing with water and drying to obtain a bead-like polymer. 20 ° C. of this bead polymer,
The intrinsic viscosity measured in chloroform is 0.314 dl /
g.

Production method of acrylic resin (3) 500 parts of pure water is charged into a polymerization vessel equipped with a reflux condenser, and then 460 parts of methyl methacrylate and 40 parts of methyl acrylate are added.
Parts, a mixed solution of 2.5 parts of lauryl peroxide and 1 part of lauryl mercaptan was charged, the atmosphere was replaced with nitrogen while stirring, and the temperature was raised to 80 ° C. for 2.5 hours, and then polymerization was performed at 95 ° C. for 1 hour. Then, it was washed with water and dried to obtain a beaded polymer. The intrinsic viscosity of the bead polymer measured in chloroform at 20 ° C. was 0.488 dl / g.

Preparation of hydrogenated product of block copolymer (1) 500 parts of cyclohexane and 14.3 parts of sec-butyllithium were charged into a pressure-resistant reaction vessel equipped with a stirrer and a dropping funnel, and the temperature was raised to 50 ° C. Then, 48 parts of styrene were continuously charged from the dropping funnel, then 304 parts of isoprene were continuously charged, and then 48 parts of styrene were continuously charged, and polymerization was performed for 10 hours. After that, the reaction system was replaced with hydrogen,
15 kg / c by adding 8 parts of diatomaceous earth-supported nickel catalyst
The reaction was carried out at 150 ° C. for 10 hours under a hydrogen pressure of m ² . The reaction product is diluted with cyclohexane, the catalyst is filtered off, and the filtrate is concentrated and dried under reduced pressure to hydrogenate the block copolymer.
The product (1) was obtained. By NMR , the water of the block copolymer
It was confirmed that the additive (1) was a styrene-hydrogenated isoprene-styrene ternary block copolymer . Also,
The hydrogenated product (1) of the lock copolymer has a styrene content of 2
It was 4.7% by weight . The GPC from (gel permeation chromatography) analysis, the block copolymer
The hydrogenated product (1) has a styrene block number average molecular weight of 3,800 and an isoprene block number average molecular weight of 2
3,200, number average molecular weight of the total Ru der 30,800
I confirmed that . The hydrogenation rate was 9 by the iodine value measurement.
It confirmed the 8.9% der Rukoto.

Production of hydrogenated product of block copolymer (2) 500 parts of cyclohexane and 16.9 parts of s-butyllithium were charged into a pressure-resistant reaction vessel equipped with a stirrer and a dropping funnel, and heated to 50 ° C. Then, 60 parts of styrene were continuously charged from the dropping funnel, then 280 parts of isoprene were continuously charged, and then 60 parts of styrene were continuously charged to perform polymerization for 7 hours. After that, the reaction system was replaced with hydrogen, and 25 parts of a diatomaceous earth-supported nickel catalyst was added, and 15 kg / c was added.
The reaction was carried out at 150 ° C. for 7 hours under a hydrogen pressure of m ² . The reaction product was diluted with cyclohexane, and the catalyst was separated by filtration. Then, the filtrate was concentrated and dried under reduced pressure to obtain a hydrogenated product (2) of a block copolymer . Hydrogenation of block copolymer by NMR
The product (2) is styrene-hydrogenated isoprene-styrene.
It was confirmed that this was the original block copolymer . Also, bro
The hydrogenated product (2) of the acrylic copolymer has a styrene content of 30.
It was 8% by weight . Also from GP C analysis, block copolymerization
Coalescence of hydrogenated product (2) has a number average molecular weight of the styrene block is 5,500, the number average molecular weight of the isoprene block is 24,100, the number average molecular weight of the total 35, 100 der
I confirmed that . The degree of hydrogenation by iodine value measurement was confirmed 93.2% der Rukoto.

Preparation of hydrogenated product (3) of block copolymer 500 parts of cyclohexane and 9 parts of s-butyllithium were charged into a pressure-resistant reaction vessel equipped with a stirrer and a dropping funnel.
The temperature was raised to 50 ° C., and 120 parts of styrene were continuously charged from the dropping funnel, then 160 parts of isoprene were continuously charged, and then 120 parts of styrene were continuously charged.
Polymerization was carried out for hours. Thereafter, the reaction system was replaced with hydrogen, 20 parts of a diatomaceous earth-supported nickel catalyst was added, and
^The reaction was carried out at 150 ° C. for 10 hours under a hydrogen pressure of ² . The reaction product was diluted with cyclohexane and the catalyst was separated by filtration. Then, the filtrate was concentrated and dried under reduced pressure to obtain a hydrogenated product (3) of a block copolymer . Hydrogenation of block copolymer by NMR
The product (3) is styrene-hydrogenated isoprene-styrene.
It was confirmed that this was the original block copolymer . Also, bro
The styrene content of the hydrogenated product (3) of the rubber copolymer is 61.
It was 1% by weight . Also from GP C analysis, block copolymerization
The combined hydrogenated product (3) has a styrene block number average molecular weight of 21,400 and an isoprene block number average molecular weight.
But 27,200, a number average molecular weight of the total confirmed <br/> Oh Rukoto 70,000. The degree of hydrogenation by iodine value measurement was confirmed 93.2% der Rukoto.

[0036]

[Table 1]

[0037]

[Table 2] Examples 1 to 5 and Comparative Examples 1 to 2 The acrylic resin obtained above and the hydrogenated product of the block copolymer were mixed by a mixer with the composition shown in Table 3, and placed in a closed kneader under a nitrogen atmosphere. Supply, 230 ° C, 100rpm
m and mixed for 5 minutes. Table 3 shows the physical properties measured by molding the obtained mixture into various test pieces by hot press molding.
Shown in In Table 3, ← means “same left”.

[0038]

[Table 3]

[0039]

According to the present invention, an acrylic resin having a specific structure and physical properties and a blow resin having a specific structure and physical properties are provided.
By mixing a hydrogenated product of the rubber copolymer , a thermoplastic resin composition having not only high flexibility but also excellent processability and weather resistance and transparency is provided.

Continuation of the front page (56) References JP-A-2-269138 (JP, A) JP-A-5-70699 (JP, A) JP-A-63-46254 (JP, A) JP-A-5-112726 (JP, A) JP-A-3-166247 (JP, A) JP-A-63-22851 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 33/06-33/12 C08L 53/02

Claims (1)

(57) [Claims] 1. An acrylic resin (A) containing methyl methacrylate as a main component in an amount of 10 to 90 parts by weight, a polymer block (a) composed of an aromatic vinyl compound, and a polymer composed of isoprene or a mixture of isoprene and butadiene. In a thermoplastic resin composition containing 90 to 10 parts by weight of a hydrogenated product (B) of a block copolymer having a united block (b), the acrylic resin (A) contains (1) methyl methacrylate 70 -100% by weight, 0-30% by weight of at least one alkyl acrylate having an alkyl group having 1-8 carbon atoms and 0-20% by weight of another ethylenically unsaturated compound copolymerizable therewith. (2) the intrinsic viscosity measured in chloroform at 20 ° C. is 0.1 to 0.35 dl / g, and the hydrogenated product (B) of the block copolymer is: The number average molecular weight of each polymer block in the copolymer hydrogenated product (B) (a) is from 3000 to 3000
(2) the total content of the polymer block (a) in the hydrogenated product (B) of the block copolymer is 10 to 60% by weight; and (3) the isoprene in the polymer block (b). the weight ratio of butadiene 40/60 or more and 100/0 or less, (4) number-average molecular weight of hydrogenated product (B) of the block copolymer is 30,000 to 300,000, you wherein the heat Plastic resin composition.