JP2000038469A - Expandable resin composition with suppressed heat discoloration and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an expandable resin composition suppressed in heat discoloration even if containing an inorganxc filler therein by incorporating a polyolefin resin with an inorganic filler and, as a foaming agent, a combination of azodicarbonamide with a specified amount of an oxybis(benzenesulfonylhydrazide). SOLUTION: This composition comprises (A) 100 pts.wt. of an polyolefin resin, (B) 10-200 pts.wt. of an inorganic filler, (C) azodicarbonamide, and (D) 1-50 wt.%, based on the total amount of the components C and D, of 4,4'-oxybis(benzenesulfonylhydrazide); wherein the total amount of the components C and D is pref. 1-15 pts.wt. An expanded raw laminate can be produced by processing this composition into an expandable sheet followed by laminating the sheet with a backing material and/or facing material to produce an expandable raw laminate followed by expanding it; alternatively, by expanding an expandable sheet in advance to form an expanded sheet followed by laminating it with a backing material and/or facing material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-like foam made of a polyolefin resin having a high degree of design, and more particularly to a sheet-like foam for providing building interior materials such as wallpaper and flooring. is there.

[0002]

2. Description of the Related Art Architectural interior materials such as wallpaper and flooring are conventionally made of polyvinyl chloride (hereinafter abbreviated as "PVC") and foamed by the action of azodicarbonamide (hereinafter abbreviated as "ADCA"). What was done was the mainstream. That is, PVC
Is applied on a backing material such as paper, heat-treated to produce a foamable material, and then heat-treated at a high temperature to produce AD.
CA is decomposed, and a foam is obtained by gas generated at that time. This foaming property is necessary for imparting a deep three-dimensional design. However, there has been a problem that the building interior material made of PVC has a high smoke generating property at the time of combustion. Therefore, polyolefin (hereinafter abbreviated as “PO”)
The present inventors have already proposed a building interior material in which a resin composition in which an inorganic filler is blended is used and foamed by the action of a chemical foaming agent such as ADCA (Japanese Patent Application No. 9-285126, Japanese Patent Application No. No.-207764, Japanese Patent Application No. 9-101379
issue).

[0003] In the case of building interior materials made of PVC plastisol, the thermal energy of heat treatment for producing an unfoamed raw material is relatively low, so that ADCA is decomposed at this stage (hereinafter referred to as "early decomposition"). ") Did not pose a major problem even if a large amount of the inorganic filler coexisted.
However, in the case of the PO system, the production of an unfoamed raw material, that is, the production of a foamable resin composition, the production of a foamable sheet, or the heat energy at the stage of producing the foamable raw material is high, The early degradation of ADCA cannot be ignored. that time,
When an inorganic filler coexists, there is a problem of thermal coloring in that it is colored blackish brown or red.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a foamable PO resin composition in which thermal coloring is suppressed even in the presence of an inorganic filler. Provide anti-foam sheets, foam sheets, and architectural interior materials (hereinafter, these are collectively referred to as "molded products") which have been subjected to printing and embossing (hereinafter, these are collectively referred to as "design processing"). It is in.

[0005]

Means for Solving the Problems The present inventors diligently studied this problem, and found that a specific amount of 4,4'-oxybis (benzenesulfonylhydrazide) (hereinafter referred to as "OB
SH)), OBSH surprisingly has a lower ADC onset temperature than ADCA,
Found that thermal coloring due to early decomposition of A can be suppressed,
The present invention has been completed.

That is, according to the present invention, (A) PO,
By comprising (B) an inorganic filler, (C) ADCA, and (D) OBSH, it is possible to obtain a foamable resin composition in which thermal coloring due to early decomposition of ADCA is suppressed and a molded article thereof.

[0007] The details will be described below.

[(A) PO] PO used in the present invention is a polymer containing an olefin as a monomer. Examples of such olefins include ethylene, propylene, butene, butadiene, pentene, pentadiene, hexene, hexadiene, hexatriene, heptene, heptadiene, heptatriene, octene, octadiene, octatriene, octatetraene, and isomers thereof. Specifically, it has two or more carbon atoms and has at least one carbon-carbon double bond. Examples of such a material include polyethylene, polypropylene, and ethylene-α-olefin copolymer. In addition, copolymers of the above-mentioned olefins with fatty acid vinyl, (meth) acrylate, (meth) acrylic acid and the like may be used. The polymerization method is not particularly limited, but examples include radical polymerization, anionic polymerization, coordination polymerization, and cationic polymerization. These may be used alone or in combination of two or more.

[0009] As a building interior material, flexibility is often required. In addition, the fact that the manufactured foamable sheet or the foamable raw material is warped may not be preferable in terms of design workability. In such a case, a polyethylene resin having a low crystallinity is preferably used. As a polyethylene resin of low crystallinity, ethylene and α-olefin,
Copolymers with fatty acid vinyls or (meth) acrylates are exemplified. Above all, an ethylene-vinyl acetate copolymer (hereinafter abbreviated as "EVA") or a blend thereof with another PO, which contains 10-45% by weight of a vinyl acetate unit, is flexible. so,
This is preferable because warpage hardly occurs.

[(B) Inorganic Filler] The inorganic filler is blended for the purpose of concealing the base material and making it flame-retardant by dilution of PO, which is flammable, or by heat absorption during thermal decomposition. As the inorganic filler used in the present invention, magnesium hydroxide, aluminum hydroxide, metal hydroxides such as calcium hydroxide, diantimony trioxide, diantimony pentoxide, zinc borate, zinc stannate, titanium dioxide and the like Metal oxides, sulfides such as zinc sulfide, inorganic polyphosphates such as ammonium polyphosphate and red phosphorus, metal sulfates such as calcium sulfate and barium sulfate, metal carbonates such as calcium carbonate and magnesium carbonate, magnesium silicate, Examples include, but are not limited to, metal silicates such as aluminum silicate and the like, talc, zinc hydroxystannate and the like. The magnesium hydroxide may be a solid solution with a hydroxide of a divalent metal such as Ni or Zn, or the solid solution may be localized on the surface of the magnesium hydroxide crystal. Aluminum hydroxide whose surface is treated with oxalic acid may be used. As magnesium hydroxide or aluminum hydroxide, those having zinc stannate and / or zinc hydroxystannate on the surface of these crystals may be used. The B component may be used alone, or a plurality of types may be blended and used.

The surface of the inorganic filler is reacted with a fatty acid or a derivative thereof, a phosphoric ester, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, a melamine resin, a phenol resin, an epoxy resin, melamine, or melamine. A compound treated with a compound having a plurality of functional groups capable of being crosslinked with melamine or the like is preferred in terms of suppressing aggregation, improving affinity with PO, and improving water resistance.

The amount of the component B is preferably from 10 to 200 parts by weight per 100 parts by weight of the component A (hereinafter, parts by weight per 100 parts by weight of the component A are indicated by phr). 10
If it is at least phr, it is preferable in terms of the concealing property against the base and flame retardancy, and if it is at most 200 phr, the viscosity of the resin composition will not be significantly increased, and the processability will be good. [(C) ADCA and (D) OBSH] The particle shape, average particle size, and particle size distribution of the component C and the component D used in the present invention are not particularly limited. These may be selected according to the desired foaming characteristics. However, the D component needs to be 1 to 50% by weight based on the total of the C component and the D component.
If it is less than 1% by weight, the effect of OBSH to suppress thermal coloring due to early decomposition of ADCA is insufficient. On the other hand, 50
If the content is more than 10% by weight, the OBSH itself will be decomposed at an early stage while the viscosity of the resin matrix is not sufficiently reduced, and the reduction in the expansion ratio and the roughening of the surface of the foamed sheet or foam will be remarkable.

The total amount of the components C and D depends on the type of the component A, the type and the amount of the component B, and the conditions of the foaming treatment, but is preferably in the range of 1 to 15 phr. Within this range, the amount of gas generated during the foaming process is appropriate, and a high foaming ratio can be realized without causing significant cell destruction.

[Method for Producing Resin Composition] The method for producing the resin composition of the present invention is not particularly limited. In particular,
Examples of the kneading method include an extruder, a Banbury mixer, a kneader, and a roll. As the operating conditions, it is desirable that the PO of the component A is in a molten state and that the foaming agents of the components C and D are not significantly foamed by decomposition.

[Production Method of Molded Body] There are two methods for obtaining a raw foam. After processing the resin composition produced by the above method into a foamable sheet, a foamable raw material bonded to a backing material or a skin material is produced, and then a foaming treatment is performed. The other method is to foam a foamable sheet manufactured in the same manner to form a foamed sheet, and then bond the foamed sheet to a backing material or a skin material. The method of forming the resin composition into a sheet for producing the foamable sheet is not particularly limited. That is, calender molding, inflation molding, extrusion molding, cast molding and the like are exemplified. It is desirable that the temperature for producing the foamable sheet is a temperature at which foaming does not become noticeable.

The foaming can be carried out under normal pressure by using a hot-air foaming furnace or a far-infrared heater used in the production of ordinary wallpaper. As surface materials and backing materials used for building interior materials, surface hardness, flexibility, wear resistance, etc.
The polymer is not particularly limited as long as it has the necessary properties as each member. For example, non-combustible paper treated with aluminum hydroxide or flame-retardant paper impregnated with guanidine or the like can be used as a backing material for wallpaper. General paper that has not been subjected to such processing can also be used. Examples of the skin material include sheets of polyolefin, fluorine-containing polymer, polysiloxane, and the like.

Further, in order to give an important design property as a building interior material, the surface can be printed or embossed. Printing can be performed on any of a foamable sheet, a foamed sheet, a foamable material, and a foamed material. If corona discharge treatment or ozone treatment is performed to increase the polarity of the surface prior to printing, printability is improved. When a method of applying a primer to the surface is used, printability is further improved.

The embossing can be performed on a foamed sheet or a foamed material by mechanical embossing, which is one of the embossing processes. In addition, when there is an appropriate foaming suppression ink, if the ink is partially applied to a foamable sheet or a foamable fabric and then heat-treated, only the portion where the suppression ink is not applied foams. An embossed portion having a recessed portion can be applied. In this case, when the suppression ink is mixed with a normal ink and used, it is possible to produce an interior material having a high design property in which only a specific pattern portion is depressed.

[Other additives] The essence of the present invention is that ADCA
And OBSH are used in combination, and a foaming agent other than these may be further used in combination. Examples of such a blowing agent include inorganic blowing agents such as carbonates and bicarbonates.

In order to increase the foaming speed, a foaming aid may be used in combination. The foaming aid is described, for example, in "Technical Information Association Edited by" Foam Forming Technology of Various Polymers "(1993). Examples of such foaming aids include metal oxides, metal salts of organic acids, metal compounds such as zinc phosphite, urea, glycerin, diethylene glycol and the like. Examples of the metal element of the metal compound include zinc, barium, calcium, tin, and boron. For example, zinc oxide, magnesium oxide, zinc phosphite, dibutyltin maleate, calcium-based, barium-based, and zinc-based fatty acid salts are preferred examples. In particular, fatty acid salts are preferred because they have a high affinity for the resin composition and a foaming rate control effect, and the like, and zinc stearate, zinc laurate,
Zinc acetate, barium stearate, calcium stearate and the like can be mentioned. What is necessary is just to select the compounding quantity according to a desired foaming characteristic.

Various additives and the like other than those described above can be added and applied to the resin composition and the molded article of the present invention as long as the purpose of the present invention is not impaired. For example, a modified polymer for improving the physical properties of the resin composition, a flame retardant other than the B component, an antioxidant, a light stabilizer, a crosslinking agent, an antistatic agent, an antibacterial agent, an antifungal agent, a lubricant, a pigment, and the like are additives. As an example. Examples of the coating agent include an adhesive and a primer.

Examples of the flame retardant include organic phosphorus-based flame retardants such as phosphate esters, phosphonates, phosphinates, phosphine oxides, phosphites, phosphonites, phosphinites, and phosphines; and polyphosphates of organic bases such as melamine polyphosphate and dimelamine polyphosphate. Examples thereof include salts, organic halides, melamine, melamine cyanurate, melamine isocyanurate and the like.

Examples of the antioxidant include hindered phenols, phosphites and sulfides.

Examples of the light stabilizer include light absorbers such as salicylate, hydroxybenzoate, benzotriazole, and benzophenone, and hindered amines. Examples of the cross-linking agent include peroxide-based and azo-based.

The antistatic agent is effective for preventing malfunction of a computer or the like due to static electricity and for preventing adhesion of dust.
For example, various surfactants such as an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant are exemplified.

Antibacterial and antifungal agents are used to suppress the generation of mold and various microscopic organisms on the front and back surfaces of the interior material. Quaternary ammonium salts such as pyridinium salts, quaternary phosphonium salts, and silver ions And the like. Further, compounds having the same action by a photochemical reaction, for example, titanium dioxide and the like can also be mentioned.

Lubricants are used to adjust the fluidity and sheet formability of the resin composition during melt kneading and sheet forming, and include various waxes, higher fatty acids, higher fatty acid amides, higher fatty acids and lower alcohols. And esters with aromatic alcohols and polyhydric alcohols, higher aliphatic alcohols, metal soaps, phosphates, phosphites and the like.

[0028]

Next, the present invention will be described with reference to examples and comparative examples, but the present invention is not limited to these examples.

[Raw Materials] The following raw materials were used. Melt flow rate (MFR) was measured at a test temperature of 190 ° C. and a test load of 2.16 kgf based on JIS K7210.

A component (PO) A1 EVA, vinyl acetate content 20% by weight, MFR 1.5 g / 10 minutes, manufactured by Tosoh Corporation, trade name Ultracene 631 A2 EVA, vinyl acetate content 26% by weight, MFR4. 0 g / 10 min, manufactured by Tosoh Corporation, trade name Ultracene 634 A3 ultra low density polyethylene, density 0.87 g / cm ³ , MFR 1.0 g / 10 min, manufactured by Dow Chemical Co., Ltd., trade name Engage 8100 B component ( Inorganic filler) B1 Magnesium hydroxide, surface treated product of higher fatty acid, manufactured by Kyowa Chemical Industry Co., Ltd., trade name Kisma-5A B2 Calcium carbonate, surface treated product of higher fatty acid, manufactured by Shiraishi Calcium Co., Ltd., product name NCC2310 C component (ADA) Eiwa Kasei Kogyo Co., Ltd., trade name VINHALL AC # 3 D component (OBSH) Eiwa Kasei Kogyo Co., Ltd. Name Neoserubon other, all of the examples, in the comparative example, 3 phr of zinc stearate as a foaming aid, an aromatic alcohol fatty acid ester complexes as lubricant (Katsuta Kako, trade name P
U300PL) was added at 0.5 phr.

[Sample Preparation] A resin composition having the formulation shown in Table 1 was kneaded at 150 ° C. with an open roll.
Using an open roll, the resin composition is 0.1 mm
Into a sheet, and heat-fused with a flame-retardant paper on a roll to obtain a foamable raw material. This foamed raw material was heated at 210 ° C. for 60 seconds in a small oven (manufactured by Wellna Mathis) to obtain a foamed raw material.

[Evaluation] Table 1 shows the results of visual evaluation of the coloring properties of the resin composition, the raw foam, and the raw foam. The symbol after the hue name is ++: dark color +: slightly colored No mark: slightly colored (except white) For the foaming property, the surface condition of the raw foam is visually observed. The thickness of each of the raw foam, the raw foam, and the flame-retardant paper was measured and calculated by the following equation.

Expansion ratio = (Thickness of raw foam−thickness of flame retardant paper) / (Thickness of raw foam−thickness of flame retardant paper) [Formula] [Example 1-4 and Comparative Examples 1 and 2] EVA as A component
When the amount of the D component is changed in a system in which magnesium hydroxide and titanium dioxide are used in combination as the B component, D / (C
+ D) If the ratio is in the range described in claim 1, it is clear that thermal coloring can be suppressed while maintaining the foaming characteristics.

[Examples 5 and 6 and Comparative Example 3] It is apparent that thermal coloring can be suppressed while maintaining the foaming characteristics even when the type and amount of the component B are changed.

Examples 7 and 8 and Comparative Example 4 It is clear that the effects of the present invention are effective even if the type of the component A is changed.

[0036]

[Table 1]

[0037]

As described above, the inorganic filler and ADCA
Coloration of the polyolefin foam containing OB is OB
It is clear that the combination is suppressed by SH.

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 4F074 AA16 AA20 AA22 AB05 AC17 AC19 AC26 AG01 BA13 BA18 BA28 BA95 CA21 DA02 DA59 4F100 AA01A AA18 AA21 AH03A AK03A AK68 AL05A AT00B BA01 BA02 CA23A DJ01A DJ04A EJ02 EJ02 GB04

Claims (9)

[Claims] 1. A polyolefin resin (A), an inorganic filler (B), an azodicarbonamide (C), and (D) 4,4'-
It consists of oxybis (benzenesulfonyl hydrazide), and D component is 1 to 50 with respect to the total of C component and D component
%. A foamable resin composition in which thermal coloring is suppressed, characterized in that the composition is a weight%. 2. Component B is added in an amount of 1 part by weight per 100 parts by weight of component A.
0 to 200 parts by weight, and the total of the C component and the D component is 1
The foamable resin composition according to claim 1, wherein the amount is from 15 to 15 parts by weight. 3. A foamable sheet comprising the foamable resin composition according to claim 1 or 2, wherein thermal coloring is suppressed. 4. A foamed raw material comprising the foamable sheet according to claim 3 and a skin material and / or a backing material, the thermal coloring of which is suppressed. 5. A foamed raw material obtained by heat-treating the foamable raw material according to claim 4. 6. A foamed sheet, wherein the foamable sheet according to claim 3 is foamed by heat treatment, wherein thermal coloring is suppressed. 7. The foam sheet according to claim 6, and a skin material.
Or, a foamed raw material, which is composed of a backing material and has been suppressed from being thermally colored. 8. A building interior material comprising the foamed raw material according to claim 5 or 7 as a component and subjected to printing and / or embossing. 9. A building interior material comprising the foamed sheet according to claim 6 as a constituent element and subjected to printing and / or embossing.