JP2683708B2 - Thermoplastic resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having mechanical properties, molding processability, permanent antistatic property, molding heat stability, and transparency.

[Conventional technology]

Synthetic polymer materials are used in a wide range of fields due to their excellent properties, but generally have a high electric resistivity and are easily charged, so that various obstacles caused by static electricity occur. Conventionally, for the purpose of imparting an antistatic property to a synthetic polymer material, a method of kneading a water-absorbing compound such as a polyalkylene oxide or an antistatic agent into a synthetic polymer,
A method of applying a surfactant or the like to the surface of a synthetic polymer is generally used. However, sufficient antistatic performance has not been achieved by any of the methods, and if water washing or wiping of the surface is performed, the antistatic performance disappears or the kneaded components bleed out and the quality of the material was reduced. There is a problem that the antistatic property changes over time and decreases.

On the other hand, a so-called polyetheresteramide in which a polyamide and a polyester are ester-linked via a dicarboxylic acid is known to have excellent rubber elasticity and good antistatic properties. However, the polyether ester amide has rubber elasticity and insufficient mechanical strength, so that rigidity and toughness are required, and there is also a drawback that it is not sufficient as a structural material.

Therefore, for example, in JP-A-61-246244 (hereinafter referred to as "Prior Art 1"), (A) polyether ester amide, (B) rubbery polymer to (meth) acrylic acid ester and / or aromatic Graft copolymer obtained by polymerizing a monomer such as vinyl, and a copolymer obtained by copolymerizing a monomer mixture such as (C) (meth) acrylic acid ester, aromatic vinyl and / or vinyl cyanide It is disclosed that a composition composed of (styrene-based polymer) has a permanent antistatic property.

However, since the composition of the prior art 1 is still poor in compatibility between the polyether ester amide and the styrene polymer, the composition has insufficient mechanical strength such as impact strength and cannot be put to practical use.

Also, Japanese Patent Application Laid-Open No. 60-23435 (hereinafter referred to as “prior art 2”)
), Blending a polyether ester amide with a carboxyl group-containing modified vinyl polymer. However, although the mechanical strength of the composition of the prior art 2 is improved, self-crosslinking of carboxyl groups is disclosed. Due to the reaction, it has the drawback of exhibiting poor appearance such as silver streaks and matte. Further, in the prior art 2, when the resin stays at the time of molding, the mechanical strength is reduced together with the poor appearance, and the thermal stability is poor.

On the other hand, as a method of imparting antistatic properties to the transparent resin,
JP-A-55-36237 discloses a hydrophilic rubber-like polymer obtained by copolymerizing a conjugated diene and / or an alkyl acrylate and a vinyl monomer having an oxide group. Although a method of graft-polymerizing vinyl monomers that are substantially the same has been shown, it has the drawback of being inferior in mechanical properties such as impact resistance and elastic modulus.

[Problems to be solved by the invention]

The present invention has been made against the background of the problems of the prior art, and provides a transparent thermoplastic resin composition having excellent molding heat stability and molding processability, mechanical strength, excellent antistatic properties, and excellent antistatic properties. The purpose is to do.

[Means for solving the problem]

The present invention relates to (a) a rubber-modified vinyl polymer (hereinafter referred to as “(a) component”) obtained by graft-polymerizing a vinyl-based monomer on a rubber polymer (b) rubber-modified. A rubber-modified vinyl-based heat comprising a vinyl copolymer and a vinyl-based polymer (hereinafter referred to as “component (b)”), and containing a hydroxyl group-containing vinyl monomer as a copolymerization component in at least one of these polymers. 10 to 99% by weight of a plastic resin (hereinafter referred to as “(a) component”) and (b) polyamide elastomer (hereinafter referred to as “(b) component”)
99 to 1% by weight (however, (a) + (b) = 100% by weight), which comprises only a rubbery polymer and a vinyl-based monomer constituting the component (a). Difference in refractive index from the polymer (vinyl-based polymer), (b)
The difference in refractive index between the rubber-modified vinyl polymer and the vinyl polymer constituting the component and the difference in refractive index between the component (a) and the component (b) are both 0.02 or less, and the composition 0.01% hydroxyl group-containing vinyl monomer as a copolymerization component
The present invention provides a thermoplastic resin composition characterized by containing 15 to 15% by weight.

Examples of the (a) rubber-modified vinyl-based thermoplastic resin used in the composition of the present invention include (a) a rubber-modified vinyl-based polymer obtained by graft-polymerizing a vinyl-based monomer onto a rubber-based polymer, or (B) a mixture of a rubber-modified vinyl polymer and a vinyl polymer (not rubber-modified),
A rubbery polymer is mixed with a specific vinyl polymer for the purpose of obtaining a high impact resistance.

The mixing method may be a simple mechanical blending method, but in order to obtain good compatibility, a so-called graft copolymerization in which a vinyl-based monomer or the like is graft-copolymerized in the presence of a rubbery polymer is used. The one obtained by the polymerization method is more preferable. It is also preferable to use a rubber-modified vinyl-based polymer (graft copolymer) obtained by this method and a so-called graft-blend method in which a vinyl-based polymer obtained by a separate method is mixed.

Here, as the types of the rubbery polymer, there are diene rubbers such as polybutadiene and styrene-butadiene copolymer, acrylic copolymers, ethylene-propylene- (diene) copolymers, chlorinated compounds. Examples thereof include polyethylene and polyurethane. Among them, acrylic copolymers are preferable in that good transparency can be obtained.

As a method of copolymerizing (a) a rubber-modified styrene-based thermoplastic resin used in the present invention with a hydroxyl group-containing vinyl monomer, the thermoplastic resin is (a) a rubber-modified vinyl-based polymer, or (b) Since it comprises a mixture of a rubber-modified vinyl-based polymer and a vinyl-based polymer, in the case of (a) a rubber-modified vinyl-based polymer, a hydroxyl group-containing vinyl monomer is a copolymerization component in the polymer. Further, in the case of the mixture (b), at least one of the polymers contains a hydroxyl group-containing vinyl monomer as a copolymerization component of a vinyl-based monomer.

As the vinyl-based monomer, styrene-based monomers such as styrene, α-methylstyrene and bromostinlen,
Acrylic monomers such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, i-butyl acrylate, acrylonitrile, methacrylonitrile , N-phenylmaleimide, N-cyclohexylmaleimide and the like. Among these, styrene, methyl methacrylate, and acrylonitrile are most suitable.

Further, the hydroxyl group-containing vinyl monomer has at least one unsaturated bond (double bond, triple bond),
And a compound containing a hydroxyl group. Typical examples thereof include an alcohol having a double bond, an alcohol having a triple bond, an ester of a monohydric or divalent unsaturated carboxylic acid and an unsubstituted dihydric alcohol, and an unsubstituted tricarboxylic acid of the unsaturated carboxylic acid. Esters with a hydric alcohol, esters with an unsubstituted tetrahydric alcohol, and esters with an unsubstituted pentahydric or higher alcohol.

Of the hydroxyl group-containing vinyl monomers used in the present invention, suitable representative examples include 3-hydroxy-1-propane, 4-hydroxy-1-butene, cis-4-hydroxy-2-butene, trans-4. -Hydroxy-2-butene, 3-hydroxy-2-methyl-1-propene, cis-5-hydroxy-2-pentene, trans-5-hydroxy-2-pentene, cis-1,4-dihydroxy-
2-butene, trans-1,4-dihydroxy-2-butene, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2
-Hydroxyethyl crotonate, 2,3,4,5,6-pentahydroxyhexyl acrylate, 2,3,4,5,6-pentahydroxyhexyl methacrylate, 2,3,4,5-tetrahydroxypentyl acrylate, 2 Examples include 3,3,4,5-tetrahydroxypentyl methacrylate and the like.

Among these, it is preferable to use 2-hydroxyethyl methacrylate.

These hydroxyl group-containing vinyl monomers may be used alone.
Alternatively, two or more kinds can be used in combination.

(A) As a base material when the hydroxyl group-containing vinyl monomer is graft-copolymerized with the rubber-modified vinyl-based thermoplastic resin, a rubber polymer, a graft layer of a graft copolymer, or a non-grafted vinyl-based polymer, etc. Among these, it is preferable or especially preferable.

Specific examples of the (a) rubber-modified vinyl-based thermoplastic resin thus obtained are methyl methacrylate-butadiene-styrene resin (MBS resin), acrylonitrile-butadiene-methyl methacrylate-styrene resin, methyl methacrylate. -Acrylonitrile-n-butyl acrylate-monomers in the vinyl resin to be mixed in the copolymer resin or in the copolymer resin when producing a copolymer resin such as a styrene resin (AAS resin) A part of the above is polymerized in place of the hydroxyl group-containing vinyl monomer to polymerize the hydroxyl group-containing vinyl monomer.

Among these (a) rubber-modified vinyl-based thermoplastic resins, those obtained by copolymerizing a conventional AAS resin with a hydroxyl group-containing vinyl monomer, or AAS resin and a hydroxyl group-containing vinyl monomer-methacryl A mixture of methyl acid-styrene-acrylonitrile copolymer is most suitable.

The (a) rubber-modified vinyl-based thermoplastic resin used in the present invention is produced by emulsion polymerization, solution polymerization, suspension polymerization, or the like.

In this case, as the polymerization initiator, molecular weight regulator, emulsifier, dispersant, solvent and the like used for the polymerization, those usually used in these polymerization methods can be used as they are.

(A) As a preferred method for producing a rubber-modified vinyl-based thermoplastic resin, a monomer and an additional emulsifier, a monomer, in the presence of a rubbery polymer obtained by emulsion polymerization,
Using a polymerization initiator, generally the polymerization temperature 30 ~ 150 ℃, polymerization time 1 ~ 15 hours, polymerization pressure -1.0 ~ 5.0 kg / cm ² gloft copolymer obtained by graft copolymerization (however,
It is produced by mixing an ungrafted vinyl polymer) with a vinyl polymer obtained by emulsion polymerization or solution polymerization.

Next, as the (b) polyamide elastomer used in the present invention, a hard segment (X) composed of an aminocarboxylic acid or lactam having 6 or more carbon atoms, or a nylon mn salt in which m + n is 12 or more, and a polyol, Specifically, it is composed of a soft segment (Y) such as poly (alkylene oxide) glycol, and the proportion of the X component in the elastomer is 10 to 95% by weight, preferably 20 to 90% by weight, more preferably 80 to 90% by weight. , 90% by weight
Can be mentioned.

(B) If the proportion of the X component in the elastomer is less than 10% by weight, the compatibility is poor, while if it exceeds 95% by weight, the antistatic property is poor, which is not preferable.

As the aminocarboxylic acid or lactam having 6 or more carbon atoms or the nylon mn salt (X) having m + n ≧ 12,
-Aminocaproic acid, ω-aminoenoic acid, ω-aminocaprylic acid, ω-aminobergonic acid, ω-aminocapric acid, 11-aminoundencanic acid, 12-aminododecanoic acid and other aminocarboxylic acids; caprolactam, laurolactam, etc. Lactams; nylon 6,6, nylon 6,1
0, Nylon 6,12, Nylon 11,6, Nylon 11,10, Nylon 12,6, Nylon 11,12, Nylon 12,6, Nylon 12,
Examples include nylon salts such as 10 and nylon 12,12.

Also, poly (alkylene oxide) glycol (Y)
As polyethylene glycol, poly (1,2 and
1,3-propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, block or random copolymer of ethylene oxide and propylene oxide, block or random copolymer of ethylene oxide and tetrahydrofuran, etc. Is mentioned.

The number average molecular weight of these glycols (Y) is from 200 to
It is 6,000, preferably 250-4,000. Among these glycols (Y), in that they have excellent antistatic properties,
Particularly, polyethylene glycol is preferably used.

In the present invention, both ends of the poly (alkylene oxide) glycol (Y) may be aminated or carboxylated.

The bond between the (X) node and the (Y) component may be an ester bond or an amide bond corresponding to the terminal group of the (b) polyamide elastomer.

At the time of this engagement, the third such as dicarboxylic acid or diamine
Components can be used.

As the (b) polyamide elastomer, (C)
Amine carboxylic acids or lactams having 6 or more carbon atoms, or salts of diamines and dicarboxylic acids having 6 or more carbon atoms,
(D) A polyether ester amide composed of polyethylene glycol having a number average molecular weight of 200 to 6,000 and (e) a dicarboxylic acid having 4 to 20 carbon atoms, wherein the polyether ester unit is 10 to 95% by weight. When esulamide is used, a thermoplastic resin composition having much more excellent antistatic properties can be obtained.

Of these, the component (c) is preferably caprolactam, 12-aminododecanoic acid, or hexamethylenediamine-adipate.

The component (d) has a number average molecular weight of 200 to 6,0.
It is preferably polyethylene glycol having a number average molecular weight of 250 to 4,000. When the number average molecular weight is in this range, excellent mechanical properties and antistatic properties can be obtained.

Furthermore, examples of the dicarboxylic acid as the component (e) include terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, sebacic acid, adipic acid, and dodecanoic acid. ,
Excellent color tone.

Further, when the content of the polyetherester unit in the polyetheresteramide is 10 to 95% by weight, a composition having more excellent mechanical properties and antistatic properties can be obtained.

The thermoplastic resin composition of the present invention contains (a) the rubber-modified vinyl-based thermoplastic resin and (b) a polyamide elastomer as main components, and the mixing ratio of the two is such that
10 to 99% by weight, preferably 40 to 95% by weight, more preferably 60 to 93% by weight, (b) component 90 to 1% by weight, preferably 60 to 5% by weight, more preferably 40 to 7% by weight [However, (a) + (b) = 100% by weight], and if the (b) polyamide elastomer is less than 1% by weight, moldability,
The antistatic property and impact strength are insufficient, while if it exceeds 90% by weight, the composition becomes soft and the mechanical properties are inferior, which is not preferable.

Further, the thermoplastic resin composition of the present invention has a difference in refractive index between the rubber-like polymer constituting the component (a) and the polymer containing only a vinyl monomer in the component (a), (b). The difference in refractive index between the rubber-modified vinyl polymer and the vinyl polymer constituting the component and the difference in refractive index between the component (a) and the component (b) are
It is necessary that both are set to 0.02 or less, preferably 0.01 or less.

If the difference in the refractive index between them is more than 0.02, a composition having good transparency cannot be obtained.

Furthermore, the content of the hydroxyl group-containing vinyl monomer in the thermoplastic resin composition of the present invention is 0.01 to 15% by weight, preferably 0.1 to 5% by weight, more preferably 0.1 to 5% by weight in the total composition.
It is 2% by weight, particularly preferably 0.1% by weight or more and less than 1% by weight. When the amount of the hydroxyl group-containing vinyl monomer used is less than 0.01% by weight in the total composition, the compatibility with the (b) polyamide elastomer decreases,
As a result, the impact resistance and the antistatic property are deteriorated, which is not preferable. On the other hand, when it exceeds 15% by weight, the heat of formation stability and the moldability are deteriorated, which is not preferable. Especially,
The content of hydroxyl group-containing vinyl monomer is 0.1 to 10% in the total composition.
When the content is 2% by weight or more, preferably 0.1% by weight or more and less than 1% by weight, a composition having a much better balance of physical properties such as molding heat stability, molding processability, antistatic property and impact resistance can be obtained.

The thermoplastic resin composition of the present invention is obtained by mixing the component (a) and the component (b) using a usual mixing method. For example, after mixing each component with a mixer, the mixture is melt-kneaded at 200 to 280 ° C. with an extruder and granulated. Furthermore, each component can be simply melt-kneaded and molded in a molding machine.

In addition, various compounding agents can be added to the composition of the present invention.

These compounding agents include, for example, 2,6-di-t-butyl-4-methylphenol, 2- (1-methylcyclohexyl) -4,6-dimethylphenol, 2,2-methylene-
Bis- (4-ethyl-6-t-butylphenol), 4,
Antioxidants such as 4'-thiobis- (6-t-butyl-3-methylphenol), dilaurylthiodipropionate, tris (di-nonylphenyl) phosphite, wax; pt-butylphenyl salicylate; 2,2'-
Dihydroxy-4-methoxybenzophenone, 2-
(2'-hydroxy-4'-n-octoxyphenyl)
UV absorbers such as benzotriazole; paraffin wax, stearic acid, hardened oil, stearamide, methylenebis stearamide, n-butyl stearate, ketone wax, octyl alcohol, lauryl alcohol, hydroxystearic acid triglyceride, etc .; Examples thereof include antistatic agents such as amidopropyldimethyl-β-hydroxyethylammonium nitrate; pigments and the like.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, parts and% are by weight unless otherwise specified.

Reference Example 1 (Preparation of each component) (a) Preparation of component a-1; n-butyl acrylate 60%, butadiene 20
%, Styrene 20%, emulsion polymerization of rubbery polymer latex obtained in the presence of 26 parts, methyl methacrylate 53.6
Part, acrylonitrile 11 parts, α-methylstyrene 6.8
Part of styrene and 2.6 parts of styrene were subjected to emulsion graft polymerization to obtain a rubber-modified vinyl polymer having a refractive index of 1.50. The refractive index of the rubber-like polymer was 1.50, and the refractive index of the polymer containing only the vinyl monomer was 1.51.

A-2: A monomer mixture consisting of 50 parts of methyl methacrylate, 13 parts of acrylonitrile, 8 parts of styrene and 3 parts of 2-hydroxyethyl methacrylate was emulsified in the presence of 26 parts of the rubbery polymer latex used in b-1. Graft polymerization was performed to obtain a rubber-modified vinyl polymer having a refractive index of 1.51.

The refractive index of the rubbery polymer was 1.50, and the refractive index of the polymer containing only the vinyl monomer was 1.51.

A-3; in the presence of 10.2 parts of polybutadiene latex,
A monomer mixture consisting of 57.7 parts of methyl methacrylate, 21.9 parts of styrene, and 10.2 parts of acrylonitrile was emulsion-grafted to obtain a rubber-modified vinyl polymer having a refractive index of 1.52. The refractive index of the rubbery polymer was 1.52, and the refractive index of the polymer containing only the vinyl monomer was 1.51.

B-4: Methyl methacrylate by a usual emulsion polymerization method
A copolymer of 80 parts, 5 parts of styrene and 15 parts of acrylonitrile and having a refractive index of 1.50 was obtained.

B-5; methyl methacrylate by a usual emulsion polymerization method
A copolymer having a refractive index of 1.50 and containing 75 parts, 4 parts of styrene, 16 parts of acrylonitrile and 5 parts of 2-hydroxyethyl methacrylate was obtained.

A-6; methyl methacrylate by a conventional emulsion polymerization method
A copolymer having a refractive index of 1.50 and comprising 80 parts, 5 parts of styrene, 5 parts of acrylonitrile and 10 parts of 2-hydroxyethyl methacrylate was obtained.

B-7; methyl methacrylate by a usual emulsion polymerization method
A copolymer having 30 parts, 5 parts of styrene, 15 parts of acrylonitrile and 50 parts of 2-hydroxyethyl methacrylate and having a refractive index of 1.51 was obtained.

B-8: A copolymer having a refractive index of 1.57, consisting of 67.5 parts of styrene, 22.5 parts of acrylonitrile and 10 parts of 2-hydroxyethyl acrylate, was obtained by a usual emulsion polymerization method.

(B) Preparation of component b-1; PEBAX 4011 (manufactured by Atochem, polyamide elastomer having a refractive index of 1.50) Ro-2; PEBAX 5533 (manufactured by Atochem, polyamide elastomer having a refractive index of 1.50) Examples 1 to 6 and Comparative Examples 1-6 With the compounding recipe shown in Table 1, each component was mixed using the Henschel mixer. Further, this mixture was melt-kneaded at 230 ° C. using a 50 mm venting extruder to prepare pellets.

Using this pellet, the melt flow rate (measurement condition 220 ° C., 10 kg) was measured according to JIS K7210.

Further, using the pellets, injection molding at a molding temperature of 230 ° C. using an injection molding machine IS-80A manufactured by Toshiba Machine Co., Ltd.
Test specimens were prepared and tested for Izod impact strength (ASTM D256, 1 /
4 ″ notched, 23 ℃, heat distortion temperature (ASTM D648, 18.6
kg / cm ² , 1/2 ″), flexural modulus (ASTM D790), and tensile strength (ASTM D638, tensile speed 15 mm / min) were measured.

Further, using the above-mentioned pellets, using a Toshiba Machine Co., Ltd., injection molding machine IS-25EP, molding temperature 230 ° C., diameter 100 mm,
Make a 2mm thick disc, relative humidity 50%, ambient temperature 23 ℃
After molding for 24 hours, adjust the condition for 24 hours, then leave it for 1 month, wash with detergent, and then determine the surface resistivity of the test piece using a Yokogawa-Hewlett-Packard 4329A type super insulation resistance meter. did.

Further, the test piece was used to visually determine the surface appearance. As for the evaluation criteria, ○ is good, Δ is slightly bad, × is very bad,
Respectively.

Furthermore, as an evaluation of transparency, a total light transmittance (ASTM D648) and a haze value (ASTM D1003) were measured using a test piece.

As is clear from Table 1, Examples 1 to 6 are the thermoplastic resin compositions of the present invention, all of which are excellent in fluidity, heat resistance, mechanical strength, surface appearance, transparency, and change over time.
It maintains a low surface resistance even after surface cleaning, and has excellent permanent antistatic properties.

On the other hand, when the polyamide elastomer is less than 1% (Comparative columns 1 and 6), the surface resistivity is high and does not have antistatic performance, while when it exceeds 90% (Comparative column 2), the bending is The elastic modulus and tensile strength are extremely low, and the mechanical strength is poor.

Further, when the content of the vinyl monomer containing hydroxy group in the composition is less than 0.01% (Comparative column 3), the impact strength is low, and when it exceeds 15% (Comparative example 5), the surface appearance becomes matte. Getting worse.

Further, when the difference in refractive index between the rubber-modified vinyl-based thermoplastic resin and the polyamide elastomer in the composition exceeds 0.02 (Comparative Example 4), transparency cannot be obtained.

[Effect of the Invention] The thermoplastic resin composition of the present invention is transparent, has permanent antistatic properties, is excellent in mechanical strength, moldability, heat resistance, and surface appearance, and is a magneto-optical medium in which electrostatic damage is a problem. It is useful for applications such as storage cases.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 51:04)

Claims (1)

(57) [Claims] 1. A rubber-modified vinyl-based polymer obtained by (a) (a) a rubber-based polymer graft-polymerized with a vinyl-based monomer, or (b) a rubber-modified vinyl-based polymer and a vinyl-based polymer. 10 to 99% by weight of a rubber-modified vinyl-based thermoplastic resin containing a hydroxyl group-containing vinyl monomer as a copolymerization component in at least one of these polymers, and (B) a polyamide elastomer 90 to 1% by weight. [However, (a) + (b) = 100% by weight], wherein the refractive index of the rubber-like polymer constituting the component (a) and the polymer containing only vinyl monomers Difference in refractive index between the rubber-modified vinyl polymer and the vinyl polymer constituting the component (b),
The difference in refractive index between the (a) component and the (b) component is 0.02 or less, and the composition contains 0.01 to 15% by weight of a hydroxyl group-containing vinyl monomer as a copolymer component. A thermoplastic resin composition comprising: