JP2007106847A - Transparent thermoplastic resin composition, printing film or sheet produced by using the resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent thermoplastic resin composition excellent in low whitening property, surface hardness and bending strength, and printing film or sheet prepared by using the resin composition. <P>SOLUTION: This transparent thermoplastic resin composition consists of (A) 70-94 wt.% (meth)acrylic acid ester-styrene copolymer having 1.52-1.55 refractive index, (B) 5-29 wt.% thermoplastic polyurethane, and (C) 1-10 wt.% graft polymer obtained by polymerizing a monomer mixture of 50-80 wt.% (meth)acrylic acid ester and 50-20 wt.% styrene-based monomer with a rubbery polymer having 0.05-0.15 μm weight-average particle diameter. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transparent thermoplastic resin composition excellent in low whitening property, surface hardness and bending strength, and in particular, a transparent material which can be suitably used particularly as a base material for various labels and printing films. The present invention relates to a thermoplastic resin composition and a printing film or sheet prepared using the resin composition.

Currently, in various resin molded products, coloring, plating, printing, or the like is usually performed in order to improve the design. Among them, printing is currently widely used due to the beautiful finish, but besides the method of printing directly on the molded product by the hydraulic transfer method etc., there is also a wide range of methods of pasting the prepared printing film at the time of injection molding It has been adopted.
In the latter case, transparent PVC resin or PET resin is currently the mainstream from the viewpoint of cost or transparency as the base material of the film, but from the environmental aspect of dioxin for transparent PVC resin, moldability or Due to the disadvantage of poor adhesiveness, it is currently desired to develop materials with improved environmental aspects and moldability or adhesiveness.
For such a printing film, a transparent TPU / ABS alloy (Patent Document 1: Japanese Patent Application Laid-Open No. 2003-176392) using a whitened transparent ABS resin and a special thermoplastic polyurethane (TPU) has been proposed. In such applications, high surface hardness is often required to prevent scratches as performance other than whitening and bending strength. However, at present, there is no resin or alloy as described above that has such a whitening property, bending strength, and surface hardness at a level that sufficiently satisfies them.
JP 2003-176392 A

  An object of the present invention is to provide a transparent thermoplastic resin composition excellent in low whitening property, surface hardness and bending strength, and a printing film or sheet prepared using the resin composition.

As a result of intensive studies in view of such problems, the present inventors have found that the above-described problems can be solved by mixing MS resin having a specific refractive index, thermoplastic polyurethane, and specific MBS resin. The invention has been reached.
That is, the present invention
(Meth) acrylic acid ester-styrene copolymer (A) 70 to 94% by weight, thermoplastic polyurethane (B) 5 to 29% by weight, and weight average particle diameter, with a refractive index in the range of 1.52 to 1.55 Obtained by polymerizing a monomeric mixture of 50 to 80% by weight of a (meth) acrylic acid ester monomer and 50 to 20% by weight of a styrene monomer to a rubbery polymer comprising 0.05 to 0.15 μm. A transparent thermoplastic resin composition comprising 1 to 10% by weight of the obtained graft polymer (C) is provided.

  A transparent thermoplastic resin composition excellent in low whitening property, surface hardness, and bending strength is obtained, and a printing film or sheet produced using the resin composition is used for portable terminal devices such as vehicle interior parts and PDAs. There exists an effect that it can be used conveniently.

The present invention will be described in detail below.
The transparent thermoplastic resin composition of the present invention comprises 70 to 94% by weight of a (meth) acrylic acid ester-styrene copolymer (A) having a refractive index in the range of 1.52 to 1.55 and a thermoplastic polyurethane (B ) A rubbery polymer consisting of 5 to 29% by weight, a weight average particle size of 0.05 to 0.15 μm, and a (meth) acrylic acid ester monomer 50 to 80% by weight and a styrene monomer 50 to 20% by weight. % Of the graft polymer (C) obtained by polymerizing a monomer mixture of 1% to 10% by weight.

Although there is no restriction | limiting in particular in the composition ratio of each component in the (meth) acrylic acid ester-styrene copolymer (A) used by this invention, 50-20 weight% of (meth) acrylic acid ester monomers and styrene It is preferable to be obtained by polymerizing a monomer mixture comprising 50 to 80% by weight of a system monomer.
However, it is important that the refractive index of the copolymer (A) is in the range of 1.52 to 1.55. When the refractive index is outside this range, the transparency that is a feature of the present invention is obtained. Significantly damaged. Preferably it is the range of 1.515-1.535.
Further, the molecular weight or molecular weight distribution of the copolymer (A) is not particularly limited, but is preferably 50,000 to 150,000 as a weight average molecular weight and a molecular weight distribution of less than 3 from the viewpoint of moldability and physical property balance.
The refractive index and molecular weight (distribution) are the mixing conditions of the monomers during polymerization, that is, the type and amount of each monomer, or the polymerization temperature, the type and amount of the polymerization initiator, the type of chain transfer agent and the use thereof. It can be arbitrarily adjusted according to the amount or the like.
As a polymerization method of the (meth) acrylic ester-styrene copolymer (A), an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, a bulk polymerization method, or any combination thereof can be used depending on the purpose. It is. The bulk polymerization method is particularly preferable.

  The thermoplastic polyurethane (B) used in the present invention is a polyurethane resin obtained by reacting a polyisocyanate compound (isocyanate component) and a polyhydroxyl compound (high molecular polyol and / or low molecular weight polyol).

  Examples of the polyisocyanate used in the production of the thermoplastic polyurethane (B) of the present invention include aromatic diisocyanates, alicyclic diisocyanates, and modified products of these diisocyanates. Specific examples of such diisocyanates include, for example, hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, cyclohexane diisocyanate, pyridine diisocyanate, toluidine diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4. -Diphenylmethane diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, 1,5-naphthylene diisocyanate and mixtures thereof.

  The polymer polyol as the polyhydroxyl compound used in the production of the thermoplastic polyurethane of the present invention is preferably a polyester polyol, a polyether polyol, a polybutadiene polyol, a polycarbonate polyol, a polyester polyether polyol or a mixture thereof.

  The polyester polyol used for the production of the thermoplastic polyurethane of the present invention includes a polyhydric alcohol and polybasic carboxylic acid condensate, a hydroxycarboxylic acid and polyhydric alcohol condensate, etc. For example, ethylene glycol, 1,2-propylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 2,2-dimethyl-1,3-propanediol, diethylene glycol, 1,5-pentamethylene glycol, 1 , 6-hexamethylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol and the like alone or as a mixture. Polybasic carboxylic acids include dibasic acids such as succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, speric acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, hexahydroisophthalic acid, etc. Is exemplified. As the condensate of hydroxycarboxylic acid and polyhydric alcohol, castor oil, a reaction product such as castor oil and ethylene glycol, propylene glycol or the like can be used.

  As the low molecular polyol used in the production of the thermoplastic polyurethane of the present invention, the diol can be used.

  Furthermore, polycaprolactone diols obtained by ring-opening addition polymerization of ε-caprolactam in the presence of glycol or the like can also be used as the polyester polyol used for producing the thermoplastic polyurethane of the present invention. As these caprolactone diols, those obtained by addition polymerization of one or more of ε-caprolactam, σ-valerolactone and the like to the polyhydric alcohols described above can be used.

  As the polyether polyol used in the production of the thermoplastic polyurethane of the present invention, one or more of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran are used as compounds having two or more active hydrogens. Examples of addition-polymerized products include polyethylene glycol, polypropylene glycol, and polymethylene glycol. Examples of the compound having two or more active hydrogens include polyhydric alcohols and polybasic carboxylic acids described above, amines such as ethylenediamine and hexamethylenediamine, polyhydric phenols such as resorcin and bisphenol, A castor oil etc. are mentioned.

  The polybutadiene diol used in the production of the thermoplastic polyurethane of the present invention is a diene polymer or copolymer having 4 to 12 carbon atoms having a number average molecular weight of 500 to 25000, and further, these diene monomers and 2 to 22 carbon atoms. Of olefinic addition polymer monomers, for example, polybutadiene homopolymer, polyisoprene homopolymer, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, and the like.

  Polycarbonate polyols used in the production of the thermoplastic polyurethane of the present invention include polyhydric alcohols such as 1,6-hexanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol and phosgene, chloroacetic acid. The number average molecular weight is about 300 to 15000 obtained by condensation with an ester, dialkyl carbonate or diallyl carbonate.

  The refractive index of the thermoplastic polyurethane of the present invention is 1.52 from the viewpoint of providing transparency by mixing with the above (meth) acrylate-styrene copolymer (A) and the following graft polymer (C). It is preferable to be in the range of 1.58.

  The graft polymer (C) used in the present invention is a 50 to 80 weight (meth) acrylate monomer in the presence of a rubbery polymer having a weight average particle size of 0.05 to 0.15 μm. % And a monomer mixture of 50 to 20% by weight of a styrene-based monomer is obtained by polymerization.

  When the weight average particle diameter of the rubber-like polymer is less than 0.05 μm or more than 0.15 μm, the impact strength and transparency are remarkably impaired, and the surface hardness and the whitening property which are the objects of the present invention are inferior. A malfunction occurs.

  Examples of the rubber-like polymer include polybutadiene, styrene-butadiene polymer, acrylonitrile-butadiene polymer, ethylene-propylene polymer, ethylene-propylene-nonconjugated diene polymer, and acrylic polymer. However, among these, a styrene-butadiene polymer is preferable, and a styrene-butadiene polymer having a styrene content of 3 to 10% by weight is particularly preferable.

  The composition of the monomer mixture is 50 to 80% by weight of (meth) acrylic acid ester monomer and 50 to 20% by weight of styrene monomer, but 50 (meth) acrylic acid ester monomer is used. If it is less than 80% by weight or more than 80% by weight, the transparency of the final product is inferior, which is not preferable.

The ratio of the rubber-like polymer and the monomer mixture is not particularly limited, but is 30 to 80% by weight of the rubber-like polymer and 70 to 20% by weight of the monomer mixture from the viewpoint of balance between transparency and bending strength. It is preferable that The graft ratio of the graft polymer (C) is not particularly limited, but is preferably 30% or more. Further, the molecular weight of the acetone-soluble part in the graft polymer (C) is not particularly limited, but is preferably in the range of 30000 to 150,000 in terms of the balance between moldability and strength.
Regarding the weight average particle diameter of the rubbery polymer, the graft ratio of the graft polymer, and the molecular weight of the acetone soluble part, the conditions during the polymerization, that is, the type and amount of the polymerization initiator, the polymerization rate, the temperature during the polymerization, respectively. Or it can adjust arbitrarily by changing stirring conditions etc.

  As a polymerization method of the graft polymer (C), an emulsion polymerization method is generally used, but other polymerization methods such as a solution polymerization method and a bulk polymerization method, or any combination thereof can be used depending on the purpose. is there.

  The (meth) acrylic acid ester monomer used in the above (meth) acrylic acid ester-styrene copolymer (A) and graft polymer (C) is methyl (meth) acrylate, ethyl (meth). Acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylexyl acrylate, etc. are styrene monomers such as styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methyl. Examples include styrene, α-methyl-p-methylstyrene, halogenated styrene, ethyl styrene, p-isopropyl styrene, pt-butyl styrene, 2,4-dimethyl styrene, divinyl benzene, etc., one or two of each. The above can be used according to the purpose.

  Although there is no restriction | limiting in particular in the mixing method of the various polymers obtained by this invention, It is common to mix in a powder or a pellet state.

  Furthermore, pigments, dyes, antioxidants, heat stabilizers, UV absorbers, antistatic agents, and the like can be added to the transparent thermoplastic resin composition of the present invention as necessary, and among them, hindered amine light stability. The addition of an agent and a phenolic antioxidant is preferred in terms of preventing discoloration of the product during processing. In addition, it is preferable that each addition amount exists in the range of 0.05 to 0.2 weight% with respect to 100 weight% of resin from the point of the transparency or external appearance of a molded article.

  The transparent thermoplastic resin composition of the present invention can easily produce a desired film, sheet, or molded product by various processing methods such as roll processing, extrusion sheet processing, calendar processing, and blow processing. Although there is no restriction | limiting in particular about the processing temperature at the time of shaping | molding, It is preferable that it is the range of 180-240 degreeC from a viewpoint which prevents coloring of a molded article.

  The transparent thermoplastic resin composition obtained above can be suitably used as a base material for various printing sheets that are particularly required to have low whitening property, surface hardness and bending strength.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not restrict | limited at all by these.

(Meth) acrylic acid ester-styrene copolymer (A)
A-1: A (meth) acrylic acid ester-styrene copolymer A-1 (refractive index: 1.53) comprising 60% by weight of methyl methacrylate and 40% by weight of styrene was obtained by a known bulk polymerization method.
A-2: A (meth) acrylic acid ester-styrene copolymer A-2 (refractive index: 1.54) consisting of 50 parts by weight of methyl methacrylate and 50 parts by weight of styrene was obtained by a known bulk polymerization method.
Ai: Polystyrene resin Ai (refractive index: 1.58) was obtained by a known bulk polymerization method.

Thermoplastic polyurethane (B)
B-1: Peresen 2102-80A manufactured by Dow Chemical Company (refractive index: 1.53)

Graft polymer (C)
C-1: From a styrene-butadiene rubber latex (styrene 5 wt%, weight average particle size 0.13 μm) 50 parts by weight (solid content), methyl methacrylate 35 parts by weight, styrene 15 parts by weight by a known emulsion polymerization method Graft polymer C-1 (graft ratio 65%) was obtained.
C-2: Styrene-butadiene rubber latex (styrene 5% by weight, weight average particle size 0.08 μm) 50 parts by weight (solid content), methyl methacrylate 35 parts by weight, styrene 15 parts by weight in the same manner as C-1. A graft polymer C-2 (graft ratio: 62%) was obtained.
Ci: 50 parts by weight (solid content) of styrene-butadiene rubber latex (styrene 5% by weight, weight average particle diameter 0.25 μm), 35 parts by weight of methyl methacrylate, 15 parts by weight of styrene by the same method as C-1. A graft polymer C-i (graft ratio: 48%) was obtained.
C-ii: Made of 50 parts by weight (solid content) of styrene-butadiene rubber latex (5% by weight of styrene, 0.1 μm in weight average particle size), 15 parts by weight of acrylonitrile, and 35 parts by weight of styrene by the same method as A-1. A graft polymer C-ii (graft ratio 57%) was obtained.

Additive (D)
D-1: Phenolic antioxidant Sumilizer BP-76 (manufactured by Sumitomo Chemical)

Examples and Comparative Examples After mixing various components at the ratios shown in Table 1, melt mixing was performed using a vented 40 mm single screw extruder (manufactured by Tanabe Plastics Machinery Co., Ltd.) at a set temperature of 210 ° C. .
In addition, 1 part of ethylenebisstearylamide was added to all samples as a lubricant. The obtained pellet produced a sheet having a thickness of 1 mm using a 40 mm sheet extruder (manufactured by Tanabe Plastics Machinery Co., Ltd.) at a molding temperature of 200 ° C., and was evaluated by the following test method. .

In the examples, various evaluations were performed by the following methods.
Surface hardness : Pencil hardness was measured according to JIS K-5400.
Low whitening property : The presence or absence of whitening and the presence or absence of breakage when the sheet was bent 180 ° were visually determined.
No whitening to slightly whitening: ○
Remarkably whitened: ×
No break: ○
With break: ×
Transparency : Total light transmittance (%) was measured using a reflection / transmittance meter HR-100 (manufactured by Murakami Color Research Laboratory).

The transparent thermoplastic resin composition of the present invention can be suitably used for molded products that require low whitening, surface hardness, transparency and bending strength, such as protective sheets for liquid crystals, various labels, printing sheets and the like. It is.

Claims (4)

(Meth) acrylic acid ester-styrene copolymer (A) 70 to 94% by weight, thermoplastic polyurethane (B) 5 to 29% by weight, and weight average particle diameter, with a refractive index in the range of 1.52 to 1.55 Obtained by polymerizing a monomeric mixture of 50 to 80% by weight of a (meth) acrylic acid ester monomer and 50 to 20% by weight of a styrene monomer to a rubbery polymer comprising 0.05 to 0.15 μm. A transparent thermoplastic resin composition comprising 1 to 10% by weight of the obtained graft polymer (C). The transparent thermoplastic resin composition according to claim 1, wherein a thermoplastic polyurethane having a refractive index in the range of 1.52 to 1.60 is used. The transparent thermoplastic resin composition according to claim 1 or 2, wherein the graft ratio of the graft polymer (C) is 30% or more. A printing film or sheet produced using the transparent thermoplastic resin composition according to claim 1.