JP2001106742A - Methacrylic ester resin composition and film produced by forming the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a methacrylate resin composition having good elongation, moldability, oil resistance and solvent resistance. SOLUTION: In the presence of (a) 5-65 pts.wt. of an acrylate elastomer prepared by copolymerizing monomers including alkyl acrylate monomers and a polyfunctional monomer bearing two or more non-cojugated double bonds in one molecule, (b) 95-35 pts.wt. of a monomer mixture of 60-95 wt.% of an alkyl methacrylate, 30-0 wt.% of an alkyl acrylate and 5-40 wt.% of an alkoxyalkyl (meth)acrylate and/or alkylthioalkyl (meth)acrylate are copolymerized to obtain the objective methacrylate resin composition. The resultant resin composition is formed to give the objective film of 10-300 μm thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a methacrylate resin composition having good elongation, moldability, oil resistance and solvent resistance, and a film obtained by molding the same.

[0002]

2. Description of the Related Art Methacrylate resins are particularly excellent in weather resistance and transparency among plastics, and are used in various fields, for example, formed into sheets and films, and laminated on various materials such as plastics, woods and metals. It is widely used for preventing deterioration of materials and maintaining aesthetic appearance.

[0003] However, these methacrylate resins are generally brittle, and their elongation at low temperatures is particularly insufficient.

As a method for overcoming this, there is a method of increasing the multilayer structure and the content of acrylate. However, although the brittleness is eliminated by the former method, the elongation is still insufficient, and the latter method has a problem that oil resistance and solvent resistance are reduced.

[0005]

Means for Solving the Problems As a result of intensive studies to overcome such problems, the present inventors have found that a monomer containing an ester of alcohol and acrylic acid having an ether bond in the presence of an acrylic ester-based elastic material. It has been found that by polymerizing, it is possible to achieve both elongation and solvent resistance without impairing the moldability, and the present invention has been made.

That is, in the present invention, 60 to 100% by weight of alkyl acrylate, 0 to 40% by weight of alkyl methacrylate, 0 to 40% by weight of alkoxy (meth) acrylate and / or alkylthioalkyl (meth) acrylate And a monomer composed of 0 to 40% by weight (100% by weight in total) of other vinyl monomers, and 2 per molecule capable of copolymerizing with the monomer.
Acrylate-based elastic body (a) obtained by polymerizing 0.05 to 5 parts by weight of a polyfunctional monomer having at least two non-conjugated double bonds with respect to 100 parts by weight of the monomer, 5 to 65 parts by weight Alkyl methacrylate in the presence of
Wt%, acrylic acid alkyl ester 30-0 wt%,
Alkoxy (meth) acrylate and / or alkylthioalkyl (meth) acrylate
A methacrylate-based resin composition (claim 1) obtained by polymerizing 95 to 35 parts by weight of a monomer mixture (b) consisting of 40% by weight and a resin composition obtained by molding the resin composition according to claim 1 A film having a thickness of 300 to 300 m (Claim 2)
About.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The acrylic ester-based elastic body in the present invention is (a) a copolymer having a uniform or multilayer structure containing an acrylic ester as a main component.

[0008] Ratio of acrylic ester, alkyl methacrylate, alkoxy (meth) acrylate and / or alkylthioalkyl (meth) acrylate and other vinyl monomers in acrylic ester-based elastic material (a) Is an acrylate ester 60-
100% by weight, preferably 75 to 100% by weight, alkyl methacrylate 40 to 0% by weight, preferably 25 to 0% by weight alkoxy (meth) acrylate and / or alkyl thioalkyl (meth) acrylate 0 to 0% 40% by weight, preferably 1 to 35% by weight, and the proportion of other vinyl monomers is 0 to 40% by weight.
The polyfunctional monomer having two or more non-conjugated double bonds per molecule copolymerizable with the monomer is 0.05 to 5 parts by weight, preferably 100 to 5 parts by weight of the monomer. Is 0.
1 to 3 parts by weight. If the ratio is out of this range, the glass transition temperature (hereinafter referred to as Tg) of the acrylic ester-based elastic body (a) becomes high, which is disadvantageous in terms of impact resistance. Tg is preferably 0 ° C or lower, more preferably -10 ° C or lower.

The weight average particle size of the acrylate type elastic material (a) may be a usual size, but is 300 to 3000.
Is more preferable, and 400 to 1500 is more preferable. If it is less than 300 °, the impact resistance decreases, and if it exceeds 3000 °, the transparency of the film decreases, which is not preferable. The monomers may be charged all at once at the beginning of the polymerization, or may be added continuously or intermittently. Further, after a part is charged and polymerized to prepare a seed, the remaining part may be added. The addition of these monomers can be selected according to the purpose of controlling the heat generation during polymerization and adjusting the particle size.

The alkyl acrylate used for the polymerization component of the acrylate-based elastic material (a) of the present invention preferably has 1 to 8 carbon atoms in the alkyl group, and may be linear or branched. Examples include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, and the like.

As the alkyl methacrylate, those having an alkyl group having 1 to 4 carbon atoms are preferred. Examples include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate.

The (meth) acrylic acid alkoxy ester is preferably an ester of acrylic acid or methacrylic acid with a glycol monoalkyl ether having 1 to 8 carbon atoms having a methoxy group, an ethoxy group or a propyloxy group. It may be chain-like or branched. Examples of the alkoxy acrylate include 2-methoxyethyl acrylate, 3-methoxypropyl acrylate, 3-methoxybutyl acrylate, 2-ethoxyethyl acrylate, and 3-ethoxypropyl acrylate. These are used alone or in combination of two or more. As the alkoxyester, 2-methoxyethyl acrylate, 3-methoxypropyl acrylate, 3-methoxybutyl acrylate, and as the alkylthioalkyl (meth) acrylate, the number of carbon atoms having a methylthioether group, an ethylthioether group, or a propylthioether group Esters of acrylic acid or methacrylic acid with 1 to 8 alcohols are preferred, and the alkylthioalkyl group may be linear or branched.

Examples of the alkylthioalkyl acrylate include 2-methylthioethyl acrylate, 3-methylthiopropyl acrylate and 4-methylthiobutyl acrylate. Examples of the alkylthioalkyl methacrylate include 2-methylthioethyl methacrylate.

Other vinyl monomers include vinyl cyanide such as acrylonitrile and methacrylonitrile; aromatic vinyl such as styrene, vinyltoluene, α-methylstyrene and chlorostyrene; (meth) acrylic acid; A) (meth) acrylic acid such as sodium acrylate and salts thereof, glycidyl acrylate, glycidyl methacrylate, monoglycidyl itaconate, diglycidyl itaconate, glycidyl p-styrenecarboxylate, allyl glycidyl ether, α-methylallyl glycidyl Ether, styrene-p-glycidyl ether, p-glycidylstyrene, N- [4-
Epoxy group-containing vinyl monomers such as (2,3-epoxypropoxy) -3,5-dimethylenylmethyl] acrylamide are exemplified, and those copolymerized with the above monomers are preferable. These are used alone or in combination of two or more.

Examples of the polyfunctional monomer having two or more non-conjugated double bonds per molecule copolymerizable with the monomer include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate. , Tetramethylolmethane tetramethacrylate, dipropylene glycol dimethacrylate, and corresponding acrylates, vinyl-type crosslinkable monomers such as divinylbenzene, divinyladipate, diallyl phthalate, diallyl maleate, allyl acrylate, triallyl cyanide Acrylic type crosslinkable monomers such as nurate are exemplified.
It is used in combination of two or more kinds.

The gel content of the acrylate-based elastic material (a) is not particularly limited, but is preferably 5% or more, more preferably 10% or more. The gel content is JI
Based on SK-6388, the detailed measurement method is as follows. If the gel content is less than 5%, the impact resistance tends to be lower than 50% or more. A predetermined amount of an acrylic ester-based elastic material (a) is sampled on a 100-mesh wire net, immersed in methyl ethyl ketone at 23 ° C. for 48 hours, dried under reduced pressure to remove methyl ethyl ketone, and the weight that has become a constant weight is read. I do.

Gel content (%) = weight after re-drying / amount of sample collected × 100 (%) In the present invention, an acrylic ester-based elastic material (a)
Of monomer mixture (b) in the presence of At this time, the method of adding the monomer mixture (b) is not particularly limited. It is, of course, possible to add the monomer mixture (b) in its entirety, to add it all at once, or to add it separately, or to add the remaining charge at an initial stage in portions.

The methacrylate resin of the present invention comprises:
Acrylate-based elastic body (a) has a solid content of 5 to 5.
65 parts by weight, preferably 10 to 50 parts by weight, for example, in the form of latex, in the presence of the alkyl methacrylate 60 to 95% by weight, preferably 60 to 85% by weight, and the alkyl acrylate 30 to 0% by weight preferably Is 5 to 40% by weight of alkoxy (meth) acrylate and / or alkylthioalkyl (meth) acrylate, preferably 15 to 4% by weight.
It is obtained by polymerizing 95 to 35 parts by weight, preferably 50 to 90 parts by weight of a monomer mixture (b) consisting of 0%.

The alkyl acrylate used in the monomer mixture (b) preferably has 1 to 8 carbon atoms in the alkyl group, and may be linear or branched. Examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate.

The methacrylic acid alkyl ester is preferably an alkyl group having an alkyl group having 1 to 4 carbon atoms. Examples thereof include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate.

The (meth) acrylic acid alkoxy ester is preferably an ester of acrylic acid or methacrylic acid with a glycol monoalkyl ether having 1 to 8 carbon atoms having a methoxy group, an ethoxy group or a propyloxy group. It may be chain-like or branched. Examples of the alkoxy acrylate include 2-methoxyethyl acrylate, 3-methoxypropyl acrylate, 3-methoxybutyl acrylate, 2-ethoxyethyl acrylate, and 3-ethoxypropyl acrylate. Examples of the methacrylic acid alkoxy ester include 2-methoxyethyl methacrylate and 2-ethoxyethyl methacrylate. These are used alone or in combination of two or more.

The (meth) acrylic acid alkylthioalkyl ester includes a methylthioether group, an ethylthioether group and a propylthioether group having 1 to 1 carbon atoms.
Preferred is an ester of alcohol and acrylic acid or methacrylic acid with the alcohol No. 8, and the alkylthioalkyl group may be linear or branched. Examples of the alkyl thioalkyl acrylate include 2-methylthioethyl acrylate, 3-methylthiopropyl acrylate, and 4-methylthiobutyl acrylate. Examples of the alkylthioalkyl methacrylate include 2-methylthioethyl methacrylate.

The polymerization initiator used for the polymerization of the methacrylate resin composition of the present invention is a usual free radical generation initiator. These may be of the same type or different types throughout the polymerization step of the acrylate-based elastic body (a) and the polymerization step of the monomer mixture (b). For example, potassium persulfate, inorganic peroxides such as sodium persulfate, cumene hydroperoxide,
hydroperoxides such as p-menthane hydroperoxide, di-t-butyl hydroperoxide, benzoyl peroxide, lauroyl peroxide,
Examples thereof include organic peroxides such as cumene peroxide and oil-soluble initiators such as azoisobutyronitrile.
It is used in combination of two or more kinds. Further, these and sodium sulfite, acid sodium sulfite sodium thiosulfate,
Ordinary redox initiators combined with reducing agents such as sodium thiosulfate, sodium formaldehyde sulfoxylate, glucose, ascorbic acid, hydroxyacetonic acid, ferrous sulfate, and complexes of ferrous sulfate with disodium ethylenediaminetetraacetate Can also be used. In addition, if necessary, a molecular weight modifier such as mercaptans can be used.

The polymerization method is not particularly limited as long as the composition within the scope of the present invention as described above is obtained. For example, known bulk polymerization, solution polymerization, bulk-suspension polymerization, suspension polymerization,
Emulsion polymerization, emulsion-suspension polymerization, emulsion-bulk polymerization, or any other polymerization method may be used, but the emulsion polymerization method is preferred because the volume ratio of the graft portion and the rubbery polymer portion is easily controlled. preferable. The emulsifier used in the emulsion polymerization method is not particularly limited, for example, alkyl sulfate,
Anionic surfactants such as alkyl benzene sulfonates, sulfosuccinic acid alkyl ester salts, and long-chain alkyl carboxylate salts; and non-ionic surfactants such as reaction products of alkylphenols, aliphatic alcohols, and propylene oxides with ethylene oxide and the like. Illustrative ionic surfactants,
These may be used alone or in combination of two or more, and if necessary, a cationic surfactant such as an alkylamine salt may be used.

The graft ratio of the methacrylate-based resin composition (the acrylate-based elastomer (a) is used as a trunk polymer) is 20 to 200%, preferably 50 to 150%.
%, More preferably 80 to 120%. When the graft ratio is less than 20%, the solvent resistance decreases, which is not preferable. When it exceeds 200%, the processability decreases, which is not preferable.

The reduced viscosity (N, N'-dimethylformaldehyde solution, 30 ° C.) of the methyl ethyl ketone-soluble portion of the methacrylate resin composition is 0.1 to 0.6 dl.
/ G is preferred, and more preferably 0.15-0.
It is in the range of 4 dl / g. If the reduced viscosity is less than 0.1 dl / g, impact resistance, chemical resistance, etc. decrease, which is not preferable.
On the other hand, if it exceeds 0.6 dl / g, molding processability is undesirably reduced.

Granulation and molding can be carried out by a method known per se. For example, a resin powder obtained by coagulating, dehydrating, and drying terrax of a methacrylic acid ester resin may be melt-kneaded with a roll, a screw, a Banbury mixer, a kneader, or the like, and then subjected to molding. Further, a film or sheet can be obtained by an inflation method or a T-die method. Also, if necessary, stabilizers, light absorbers, ultraviolet absorbers, pigments, dyes, antistatic agents, antibacterial
One or more deodorants can be added.

If necessary, the gloss of the surface of the molded film can be reduced by a known method. For example, it can be carried out by a method of kneading an inorganic filler or crosslinkable polymer particles, a method of copolymerizing an epoxy group-containing monomer, a method of using a linear polymer having a polar group, and the like.

The methacrylate ester resin composition can be further blended with a methyl methacrylate polymer. The methyl methacrylate polymer to be blended refers to a copolymer or a homopolymer containing 60% or more of methyl methacrylate, and the method of blending is not particularly limited, and a known method can be used. If necessary, stabilizers, light absorbers, ultraviolet absorbers, pigments, dyes,
One or more antistatic agents, antibacterial / deodorizing agents, etc. can be added.

[0030]

The present invention will be specifically described below with reference to examples. Parts in Examples and Comparative Examples are parts by weight, and% is% by weight.
Represents The measurement and evaluation in the examples and comparative examples were performed under the following conditions and methods. (1) MI: melt index 230 ° C. X 5 kg (g
/ 10 min). (2) Film elongation: The film is JIS K-6732
Measured according to. (3) Workability: A 25 μm film was extruded with a T-die extruder and evaluated according to the following criteria.

Δ: No film breakage. It can be extruded stably with uniform thickness.

×: Film cut. Extrusion is unstable. (4) Solvent resistance: A film of 40 μm is cut into a rectangle having a length of 10 cm and a width of 1 cm in the TD direction. A 3 gram weight was attached, and the sample was suspended in toluene at 23 ° C. so that about 5 cm was immersed therein, and evaluated by a time required for breaking.

The abbreviations represent the following substances, respectively. OSA: sodium dioctyl sulfosuccinate BA: butyl acrylate MMA: methyl methacrylate MEA: 2-methoxyethyl acrylate CHP: cumene hydroperoxide TAC: triallyl cyanurate tDM: tertiary decyl mercaptan.

Examples 1-4, Comparative Examples 1-2 An 8 L polymerization machine equipped with a stirrer, thermometer, nitrogen gas introduction tube, monomer supply tube, and reflux condenser was charged with the following substances and OSA shown in Table 1. It is.

Water 200 parts Sodium formaldehyde sulfoxylate 0.1 part Ferrous sulfate 0.001 part Disodium ethylenediaminetetraacetate 0.004 part A state in which the inside of the polymerization machine is sufficiently replaced with nitrogen gas and is substantially free of oxygen. After that, the internal temperature was raised to 40 ° C., and the mixture (1) was cooled to 15 ° C.
Parts / hour were continuously added and polymerized. After the completion of the addition, the polymerization was further continued for 1 hour to obtain a acrylate elastic body (a) at a polymerization conversion of 98% or more. The average particle size of the obtained acrylic ester-based elastic material (a) is shown in Table 1.
It was shown to.

Next, after the internal temperature was raised to 80 ° C., the mixture (2) was continuously added at a rate of 10 parts / hour for polymerization, and after the addition was completed, polymerization was continued for another 1 hour. The polymerization was terminated at a conversion of 98% or more to obtain a latex. The methacrylic acid ester-based resin latex is salted out with calcium chloride, washed with water and dried to obtain a resin powder, extruded at 230 ° C. with a vented extruder, and pelletized,
It was subjected to measurement and evaluation. Table 1 shows the results.

[0037]

[Table 1] From the results in Table 1, it is clear that the methacrylate ester resin compositions of the present invention represented by Examples 1 to 4 are excellent in elongation, film formability, and solvent resistance.

[0038]

As described above, the methacrylate ester resin composition of the present invention is excellent in elongation, film formability and solvent resistance.

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Claims (2)

[Claims] An alkyl acrylate 60 to 10
0% by weight, 0 to 40% by weight of alkyl methacrylate, 0 to 40% by weight of alkoxy (meth) acrylate and / or alkylthioalkyl (meth) acrylate and 0 to 40% by weight of other vinyl monomers
And a polyfunctional monomer having two or more non-conjugated double bonds per molecule copolymerizable with the monomer, and 5 parts by weight of an acrylic acid ester-based elastic body (a)
Alkyl methacrylate 6 in the presence of 65 parts by weight
0 to 95% by weight, alkyl acrylate 30 to 0
(B) 95 to 95% by weight of a monomer mixture (b) consisting of 5 to 40% by weight of an alkoxy (meth) acrylate and / or an alkylthioalkyl (meth) acrylate.
A methacrylate resin composition obtained by polymerizing 35 parts by weight. 2. A film having a thickness of 10 to 300 μm formed by molding the resin composition according to claim 1.