JP2001323167A - Resin composition and sheet made thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition to which heat resistance is donated without extremely damaging transparence of a molded item and to provide a sheet made thereof. SOLUTION: A resin composition comprises 100 pts.wt. of a resin (A) which contains 15 to 50 wt.% of an oxygen atom in a molecule and has a glass transition temperature of 0 to 90 deg.C and tanδ of 0.07 to 1 at 20 deg.C and 0.01 to 20 pts.wt. of a swellable layer silicate (B). A sheet is made of the resin composition and is not less than 50 μm thick.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a resin composition comprising a specific resin. More specifically, the present invention relates to a resin composition having a specific amount of oxygen atoms in the molecule and having excellent heat resistance comprising a resin having specific physical properties and a special silicate, and a sheet comprising the same.

[0002]

2. Description of the Related Art Acrylic resins (including acrylic copolymer resins) are excellent in transparency, mechanical properties, heat resistance, weather resistance, surface hardness, chemical properties, etc., and are used in signboards, displays, light electric and industrial sectors. , Vehicle sector, mainly automobiles, building materials
It is used in a wide variety of stores, lighting equipment, etc. Some acrylic resins are used in the form of a homopolymer or in the form of a copolymer with another acrylate or another monomer. Constituents of resin,
The composition ratio is determined by the use of the resin and the physical properties required accordingly. These acrylic resins are excellent in processability, mechanical strength, and transparency, but require further improvement in heat resistance depending on the application.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin composition having heat resistance without significantly impairing the transparency of a molded article, and a sheet comprising the same.

[0004]

Means for Solving the Problems The present inventors have developed a resin having a specific amount of oxygen atoms in the molecule, a glass transition point in a specific range, and a specific tan δ value, and a swellable layered silicate. The present inventors have found that a resin composition comprising the above can solve such problems, and have completed the present invention.

That is, the first aspect of the present invention is that an oxygen atom is contained in a molecule in an amount of 15 to 50% by weight and a glass transition point is 0 to 90%.
C. and 100 parts by weight of a resin (A) having a tan δ value of 0.07 to 1 at 20 ° C. and a swellable layered silicate (B)
It relates to a resin composition comprising 0.01 to 20 parts by weight. The second aspect of the present invention relates to the first resin composition of the present invention, wherein the resin (A) is an acrylic copolymer. A third aspect of the present invention relates to the second resin composition of the present invention, wherein the acrylic copolymer is a copolymer of methyl methacrylate and an alkyl acrylate. A fourth aspect of the present invention relates to the third resin composition of the present invention, wherein the copolymer has an alkyl acrylate content of 30 to 60% by weight. A fifth aspect of the present invention relates to the third or fourth resin composition of the present invention, wherein the alkyl acrylate is butyl acrylate. A sixth aspect of the present invention is that the butyl acrylate content is 3
The present invention relates to the fifth resin composition of the present invention, which is 0 to 40% by weight. A seventh aspect of the present invention comprises the resin composition according to any one of the first to sixth aspects, and has a thickness of 50 μm.
m or more.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The resin (A) referred to in the present invention is a resin having 15 oxygen atoms in the molecule.
-50% by weight, having a glass transition point of 0-90 ° C, 20
Any resin may be used as long as it satisfies the condition that the tan δ value in ° C. is 0.07 to 1. Typically, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, hexyl methacrylate, hexyl methacrylate, octyl methacrylate, methyl acrylate, acrylic Ethyl acrylate, propyl acrylate, n-butyl acrylate, t-butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, alkyl ester monomers such as octyl acrylate, styrene, vinyltoluene, α-methylstyrene Or a homopolymer of vinyl ester monomers such as vinyl acetate, vinyl propionate and vinyl versatate, or a copolymer comprising two or more of these monomer units. Can be mentioned.

A preferred example of the resin (A) is an acrylic copolymer. Among the acrylic copolymers, a copolymer of methyl methacrylate and a vinyl monomer can be mentioned. The vinyl monomer copolymerizable with methyl methacrylate can be selected from, for example, alkyl acrylate, alkyl methacrylate, and the like. Among such vinyl monomers, the alkyl acrylate is preferably an alkyl acrylate having an alkyl group having 2 to 10 carbon atoms, such as ethyl acrylate, propyl acrylate, and n-acrylic acid.
Butyl, isobutyl acrylate, hexyl acrylate,
Examples thereof include 2-ethylhexyl acrylate and octyl acrylate, or a combination of two or more of these. As the alkyl of the methacrylic acid alkyl ester, those having 2 to 4 carbon atoms are preferable, for example, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and tert-butyl methacrylate, or Combinations of two or more of these can be given. Of these, ethyl acrylate, n-acrylate
Butyl (hereinafter abbreviated as butyl acrylate) and 2-ethylhexyl acrylate are suitable for obtaining the required physical properties, and butyl acrylate is particularly preferred. That is,
As the resin (A), methyl methacrylate and butyl acrylate copolymer (MMABA) can be mentioned as a particularly preferred resin.

The content of the butyl acrylate monomer unit in the copolymer of methyl methacrylate and butyl acrylate is as follows:
When the resin composition of the present invention is used as a sheet, the content is preferably 30 to 60% by weight, and more preferably 30 to 50% by weight, from the viewpoint of preventing damage and flexibility. If the content of the butyl acrylate unit is less than 30% by weight, the sheet becomes insufficient in flexibility, and if the content is too large, the sheet tends to lack scratch resistance.
It is preferable to be within the above range. In addition, the production example of the methyl methacrylate-butyl acrylate copolymer by the suspension polymerization method is shown in Examples.

The resin (A) has one oxygen atom in the molecule.
5 to 50% by weight, preferably 20 to 40% by weight,
It is required that the glass transition point is 0 to 90 ° C, preferably 10 to 70 ° C, and the tan δ value at 20 ° C is 0.07 to 1, preferably 0.08 to 0.5.
If the oxygen atom content is less than 15% by weight, the sheet does not have sufficient anti-scratching properties, which is not preferable. On the other hand, if the glass transition point is lower than 0 ° C., the film will not have sufficient damage prevention properties. If the glass transition point exceeds 90 ° C., flexibility will be insufficient. To make the glass transition temperature in the range of 0 to 90 ° C,
It can be carried out by selecting the type and amount of the monomer to be copolymerized. The lower the glass transition point of a single polymer of the monomer used for copolymerization, the lower the glass transition point of the copolymer using the monomer. Further, the resin (A) needs to have a tan δ value at 20 ° C. of 0.07 or more. If the tan δ value is less than 0.07, it is not preferred because it lacks flexibility and has poor wound recovery.

The swellable phyllosilicate (B) used in the present invention includes natural or synthetic hectorite, sapotite, stevensite, beidellite, montmorillolite, nontrolite, bentonite and other smectite clay minerals and Na-type tetramethyl silicate. Silicic fluorine mica, Li-type tetrasilicic mica, Na-type fluorine teniolite, L
Swellable mica and vermiculite such as i-type fluorine teniolite and the like, and their substituted products, derivatives and mixtures can be mentioned. Smectite genus clay minerals are preferred in terms of dispersibility of the resulting clay-organic complex in organic solvents, and among them, synthetic products of 3-octahedral smectite hectorite, sapotite, stevensite and similar compounds are more preferable. preferable. These swellable phyllosilicates exhibit excellent swellability and dispersibility in water, and the resulting dispersion has a thixotropic viscosity, and is characterized by the formation of an aqueous sol-gel that is hardly colored.

These swellable phyllosilicates are treated with an organic material.
It is preferably used from the viewpoint of dispersibility in the resin (A).
As a method of organic treatment, for example, the positive electrode existing between the layers is used.
Is exchanged for quaternary ammonium ion by ion exchange method
There is a way to do that. Cation exchange capacity is 100g of clay
It is preferably 10 milliequivalents or more, more preferably 60
It is more preferable that the exchange capacity is greater than the milliequivalent and the exchange capacity is large. Swelling
Layered silicates contain up to 50% non-clay impurities
However, the amount of non-clay impurities is preferably 10% or less.
No. To introduce a quaternary ammonium ion,
Quaternary ammonium salts are used.
Such salts include the ion and, for example, Cl ^-, Br^-, N
O_Three ^-, CH_ThreeCOO^-And salts with anions such as
it can. Furthermore, various quaternary ammonium ions other than the above
And various inorganic cations may be simultaneously introduced. Up
Of quaternary ammonium ions represented by the general formula
Desirable ratio of introduction amount is 50% or more of ion exchange capacity between layers.
More preferably, it is preferably 95% or more.

A method for organically treating a swellable layered silicate comprises:
Obtained by cation exchange between layers. For example, it can be manufactured by the following method. In the first step, the swellable phyllosilicate is dispersed or suspended in water (both are referred to as suspension). The solid suspension concentration is usually 1-1.
Although 5% by weight is desirable, it can be freely set as long as the swellable phyllosilicate can be sufficiently suspended in a concentration range. Next, a quaternary ammonium salt solution is added to the swellable layered silicate suspension, or conversely, a swellable layered silicate suspension is added to the aforementioned quaternary ammonium salt solution. The organic layered silicate can be organically treated. 4th
The quaternary ammonium salt is usually mixed with the swellable phyllosilicate suspension as a mixed solution of 5 to 50% by weight, but prepared as a separate solution and mixed with the swellable phyllosilicate suspension in any order. No problem. At the time of mixing, an organic solvent such as alcohol may be added and the reaction may be performed in a liquid containing an organic solvent. The quaternary ammonium salt may be added in an excess amount relative to the cation exchange capacity. The amount thereof is preferably 0.5 to 1.5 times (in terms of milliequivalent), more preferably 0.8 to 1.2 times, the cation exchange amount of the clay.

The quaternary ammonium salt has the following general formula as a quaternary ammonium ion.

[0014]

Embedded image

In the quaternary ammonium ion of the above general formula, one of R ^{1 to} R ⁴ is an alkyl group represented by C _X H _{2X + 1} , and X = 5 to 20, preferably 12 to
18, and specific examples include dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, octadecyl and the like, and an octadecyl group is particularly preferred. One group of the remaining groups are C _Z H alkyl group represented by _{2Z + 1} (Z = _1~4) or benzyl group, preferably a methyl group or a benzyl group. Preferably, two or more groups are alkyl groups represented by C _X H _{2X + 1} ,
= 5 to 20, more preferably two groups are C _X H
An alkyl group represented by _{2X + 1} (X = 12 to 18);
The remaining two groups are a methyl group or a benzyl group. Even a quaternary ammonium ion other than the above general formula,
Any material having an affinity for xylene or chloroform is acceptable.

Although the reaction proceeds sufficiently at room temperature, it may be heated. The maximum temperature of the heating can be arbitrarily set as long as it is equal to or lower than the decomposition point of the quaternary ammonium salt to be used. The reaction time varies from several minutes to several hours depending on the reaction conditions, but is generally about 30 minutes to 2 hours. Next, the solid-liquid is separated, and the produced clay-organic complex is washed with water to sufficiently remove by-product solutes. Separation and washing of the clay-organic complex from the liquid are extremely easy, and very common filtration separation is sufficient. For example, on a laboratory scale, it is easily performed by vacuum filtration / washing using a Buchner funnel (laying filter paper) or filtration / washing by a centrifugal dehydrator. Of the organically treated swellable layered silicates thus obtained, those dispersed in chloroform or xylene are preferred from the viewpoint of dispersion in the resin (A). The average particle diameter of the organically treated swellable layered silicate when dispersed in a solvent is preferably 1 μm or more. If the particle diameter is too small, the effect of improving rigidity may not be sufficiently obtained.

The swellable layered silicate, more preferably, the organically treated swellable layered silicate (B) may be dispersed in the resin (A) in the organic solvent as described above, or may be melt-kneaded. . The melt kneading method is preferred from the viewpoint of economy.
When dispersing by melt kneading, a batch kneader or a continuous kneader may be used. It is preferable to use a twin-screw continuous kneader.

Resin (A) constituting the resin composition of the present invention
And the swellable layered silicate (B) are mixed in a proportion of resin (A) 1
The swellable layered silicate (B) is contained in an amount of 0.0
It is in the range of 1 to 20 parts by weight, and more preferably 001 to 20 parts by weight.
5 parts by weight, particularly preferably 0.01 to 2 parts by weight. When (B) exceeds 20 parts by weight, Ha of the resin composition
As the ze increases, not only the commercial value of the molded product decreases, but also the rigidity increases, the flexibility is lost, and the cost increases. On the other hand, if it is less than 0.01, the improvement in heat resistance is too small.

Resin (A) in which swellable layered silicate (B), preferably organically treated, obtained by the present invention is dispersed.
Is molded by a known method such as extrusion molding, press molding, or injection molding. The shape of the molded product is not particularly limited, but is preferably a sheet. Since the molded product has excellent heat resistance and flexibility without significantly impairing the transparency despite dispersing the swellable layered silicate (B), it is used especially in the field where heat resistance is required. It is used for seats, bags, table sheets, coasters, table mats, floor mats, etc. The thickness of the sheet is preferably 50 μm or more, and the upper limit of the thickness is determined depending on each use.

[0020]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. still,
The evaluation was performed by the following method. Heat deformation temperature: Press sheet of 300 μm thickness is 4 mm in width
Into a sample. Seiko Electronics Co., Ltd. TM
A100, load 1g, 4mm between chucks, 5
The temperature at which the sample deformed by 10% when the temperature was raised at a rate of ° C./min was defined as the heat deformation temperature. Haze: 300 μm press sheet was converted to JIS K710.
According to No. 5, the total haze was measured.

Production Example 1 (Production example of methyl methacrylate-butyl acrylate copolymer) In a 200-liter SUS autoclave, 70 parts by weight of methyl methacrylate, 30 parts by weight of butyl acrylate,
0.45 parts by weight of lauroyl peroxide, 0.1 part by weight of dodecyl mercaptan, 120 parts by weight of ion-exchanged water,
3 parts by weight of a 1.2% sodium polymethacrylate aqueous solution, 0.25 parts by weight of disodium hydrogen phosphate heptahydrate, and 0.29 parts by weight of monosodium hydrogen phosphate are mixed and heated to 75 ° C. The polymerization was started at 100 ° C., and after 100 minutes, the polymerization was further performed at 100 ° C. for 20 minutes. After polymerization, washing, dehydration and drying were performed to obtain a granular polymer. This polymer is referred to as MMABA3
0 and used in Examples and Comparative Examples. MMABA30
Means that the content of BA is 30% by weight and the content of oxygen atom in the molecule is 30
% By weight, Tg: 68.0 ° C. Butyl acrylate (BA) in the polymer was quantified by the following method. That is,
Put the sample in a furnace heated to 540 ° C and pyrolyze it.
The decomposition gas was measured by gas chromatography. The peak intensity of BA was quantified by comparing with the BA amount of the standard sample.

(Example 1 and Comparative Examples 1-2) MMABA30 obtained in the above-mentioned preparation example and an organically treated swellable layered silicate were mixed at the compounding ratios shown in Table 1 with Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.). 150 at 30C150 (R100H))
The mixture was kneaded at 60 ° C., 60 rpm for 10 minutes to obtain a resin composition. This was pressed with a press molding machine (Shinto F hydraulic press manufactured by Shinto Metal Industry Co., Ltd.) at a pressure of 100 kgf / cm ² G,
Pressing was performed at 200 ° C. for 5 minutes to obtain a pressed sheet having a thickness of 300 μm. Heat deformation temperature of this pressed sheet sample,
The haze was measured and is shown in Table 1.

[0023]

[Table 1]

[0024]

As shown in the examples, the resin composition comprising the resin (A) and the swellable phyllosilicate (B) satisfying the conditions of the present invention is remarkably formed with moderate flexibility when molded. Since it shows heat resistance and transparency is not significantly impaired, it is expected to be used in fields requiring heat resistance such as sheets, bags and table sheets.

Claims (7)

[Claims] 1. A resin (A) containing 15 to 50% by weight of oxygen atoms in the molecule, having a glass transition point of 0 to 90 ° C. and a tan δ value of 0.07 to 1 at 20 ° C. 100 parts by weight. And a swellable layered silicate (B) in an amount of 0.01 to 20 parts by weight. 2. The resin composition according to claim 1, wherein the resin (A) is an acrylic copolymer. 3. The resin composition according to claim 2, wherein the acrylic copolymer is a copolymer of methyl methacrylate and an alkyl acrylate. 4. The resin composition according to claim 3, wherein the alkyl acrylate content of the copolymer is 30 to 60% by weight. 5. The resin composition according to claim 3, wherein the alkyl acrylate is butyl acrylate. 6. The resin composition according to claim 5, wherein the content of butyl acrylate is 30 to 40% by weight. 7. A sheet comprising the resin composition according to claim 1 and having a thickness of 50 μm or more.