JP2943865B1 - Foamable resin composition and foam sheet - Google Patents

Abstract

Kind Code: A1 The present invention has good resin fluidity even when an inorganic filler is highly filled, does not foam during processing, has good foaming properties, does not generate gas that pollutes the environment during combustion, and has flame retardancy. An object of the present invention is to provide a foamable resin composition and a foam sheet using the same. SOLUTION: An ethylene vinyl acetate copolymer resin having an MFR of 0.5 to 7 g / 10 min and a melt viscosity at a tackifier or 190 ° C. of 0.1 to 10 parts by weight is used.
One or both of the amorphous α-olefin resins, which are Pascal-seconds, are mixed with 1 to 20 parts by weight, and 100 parts by weight of the mixture (resin) is mixed with 70 to 1 inorganic filler.
50 parts by weight and 2 to 15 parts by weight of a foaming agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamable resin composition and a foamed sheet, and more particularly to a foamable resin composition and a foamed sheet which are excellent in workability even when highly filled with an inorganic filler, have good foamability, and pollute the environment during combustion. It does not generate gas, has flame retardancy,
The present invention relates to a foamable resin composition having excellent dimensional stability and suitable for wallpaper, leather, flooring, and the like, and a foamed sheet using the composition.

[0002]

2. Description of the Related Art Conventionally, foams made of vinyl chloride resin have been widely used in view of workability, flame retardancy and cost, and most of synthetic resin wallpaper is made of vinyl chloride resin. . The vinyl chloride resin generates HCl gas and the like at the time of combustion, which is not preferable in terms of safety and environment. Therefore,
In recent years, a wallpaper made of an olefin resin instead of a vinyl chloride resin has been proposed in, for example, JP-A-7-186336 and JP-A-10-17724.

However, Japanese Patent Application Laid-Open Nos. Hei 7-186336 and Hei 10-17724 disclose that an ethylene-vinyl acetate copolymer resin or a crystalline α-olefin resin is highly filled with an inorganic filler in order to impart flame retardancy. And
For this reason, the fluidity of the resin during processing is low, and a sheet having a good surface state cannot be obtained. It is conceivable to increase the processing temperature to form the resin in order to increase the fluidity of the resin. However, when the processing temperature is increased, the foaming agent starts to be decomposed during processing, and thus there is a problem in production stability.

[0004] As described above, foaming of an olefin resin composition highly filled with an inorganic filler has problems in the fluidity of the resin and foaming during the processing. The fact is that no object has been proposed yet.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the problems in the prior art, in particular, has a good resin fluidity even when highly filled with an inorganic filler, and does not foam during processing. It is an object of the present invention to provide a foamable resin composition which does not generate gas that pollutes the environment during combustion and has flame retardancy, and a foamed sheet using the same.

[0006]

According to the present invention, there is provided an ethylene vinyl acetate copolymer having an MFR (melt flow rate) of 0.5 to 7 g / 10 min. 99 to 80 parts by weight of a resin (EVA) and a tackifier or a melt viscosity at 190 ° C. of 0.1
1 to 20 parts by weight of one or both of the amorphous α-olefin resins having a pressure of 10 to 10 Pascal-second is mixed with 100 parts by weight of the mixture (resin), and inorganic filler 7
The foamable resin composition contains 0 to 150 parts by weight and 2 to 15 parts by weight of a foaming agent.

According to a second aspect of the present invention, the ethylene-vinyl acetate copolymer resin has an MFR of less than 0.5 g / 10 min.
R of 0.5 g / 10 min or more, and the weighted average MFR of the mixture is 0.5 g / 10 min ≦ Σ (MFR of resin × addition amount of resin) / (total addition amount of resin) ≦ 7 g /
This is a foamable resin composition for 10 minutes.

[0008] In a third aspect, each of the foamable resin compositions is formed into a sheet, laminated with a substrate, and foamed to form a foamed sheet.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail. The foamable resin composition of the present invention has an ethylene-vinyl acetate copolymer resin (EVA) having an MFR of 0.5 to 7 g / 10 min. One or both of the amorphous α-olefin resins of 10 Pascal · sec are mixed with 1 to 20 parts by weight, and the mixture (resin) 1
With respect to 00 parts by weight, 70 to 150 parts by weight of the inorganic filler and 2 to 15 parts by weight of the foaming agent are contained, and if necessary, other compounding agents can be contained.

[0010] Ethylene vinyl acetate copolymer resin (EVA)
Can use a general commercial product. The ethylene-vinyl acetate copolymer resin used may be one kind or a mixture of two or more kinds. MFR (melt flow rate) of ethylene vinyl acetate copolymer resin alone or mixed
Is 0.5 to 7 g / 10 min as a result, preferably 1.0 to 4.0 g / min. MF for mixing
In some cases, R has a content of 7 g / 10 minutes or more. If the MFR alone or as a mixture is less than 0.5 g / 10 minutes, the flowability during processing is low, so that the processability is poor. If the MFR exceeds 7 g / 10 minutes, stickiness increases and processing becomes difficult.

The ethylene-vinyl acetate copolymer resin has an M
By mixing a material having an FR of less than 0.5 g / 10 minutes and a material having an FR of 0.5 g / 10 minutes or more, the sheet can be easily taken out, and stickiness during processing is greatly improved. This M
FR of less than 0.5 g / 10 min and 0.5 g / 10 min.
Minutes or more when mixed (MFR is 7 g / 1
It is necessary to adjust the weighted average MFR of the resin to be mixed to be 0.5 to 7 g / 10 minutes, preferably 1.0 to 4.0 g / 10 minutes. Minutes range. The weighted average MFR is Σ (MFR of resin × resin addition amount) / (total addition amount of resin), and is obtained by dividing the total product of MFR of each resin used and addition amount by the total amount of resin used. is there. That is, the following equation is obtained. (MFR1 × W1 + MFR2 × W2 +...) / (W1 + W2 +...) MFR1: MFR of resin 1, W1: addition amount of resin 1 MFR2: MFR of resin 2, W2: addition amount of resin 2

The ethylene vinyl acetate copolymer resin preferably has a vinyl acetate content of 10 to 40% by weight.
Particularly preferred is 5 to 30% by weight. When the vinyl acetate content is in the above range, a foam sheet having excellent flexibility can be obtained.
In addition, it has the feature of excellent workability.

The tackifier is generally used as a tackifier, and has a softening point of 50 ° C. to 1 ° C.
Those in the range of 50 ° C. are preferred. For example, natural rosin,
Hydrogenated rosin, rosin derivative {esterification inducer with alcohol (such as methanol, glycols, glycerin re, pentaertol, etc.), modified maleic acid, metal salt, etc.}, β-pinene, α-pinene and phenol Polymer, petroleum resin (aliphatic, aromatic, aliphatic-aromatic copolymer, alicyclic, chroman-indene resin, etc.), polyterpene resin, alkylphenol resin and the like. Of these, rosin, rosin hydride, and rosin derivatives having excellent compatibility with the ethylene-vinyl acetate copolymer resin are preferable, and rosin hydride and rosin derivatives are particularly preferable from the viewpoint of heat stability.

Amorphous α-olefin resins include homopolymers of α-olefins or copolymers thereof (for example, propylene homopolymer, propylene / ethylene copolymer, propylene / butene copolymer) and the like. The mixture includes a mixture having a relatively low molecular weight and being amorphous, and a mixture modified with an unsaturated carboxylic acid or the like. Melt viscosities at 190 ° C. (measured by a disk-type rheometer) of these amorphous α-olefins of 0.1 to 10 Pascal · sec can be used, but those having melt viscosities of 1 to 10 Pa · sec · Those in the range are preferred. If the melt viscosity exceeds 10 Pascal-second, melting during processing is not sufficient, and if the melt viscosity is less than 0.1 Pascal-second, stickiness during processing becomes large, and processing becomes difficult.

The mixing ratio of the ethylene vinyl acetate copolymer resin and one or both of the tackifier and the non-crystalline α-olefin resin is such that the tackifier or the non-crystalline α-olefin resin is 99 to 80 parts by weight of the ethylene vinyl acetate copolymer resin. 1 to 20 parts by weight, preferably 3 to 15 parts by weight of a crystalline α-olefin resin alone or in combination,
00 parts by weight. If the tackifier or the non-crystalline α-olefin resin alone or in combination is less than 1 part by weight, the flowability of the resin composition is not improved, so that the workability in the high filling compounding of the inorganic filler is poor, and a foaming agent is added. In this case, it is difficult to form a sheet without foaming during processing. On the other hand, if it exceeds 20 parts by weight, the viscosity decreases greatly, the tension during processing decreases, and it becomes difficult to take up the sheet. In addition, when a foaming agent is contained, the resin composition at a temperature at which the foaming agent decomposes is used. Melt viscosity decreases,
Good foam cannot be obtained. The use of a tackifier or an amorphous α-olefin resin alone is effective, but the amorphous α-olefin resin and the tackifier can be used in combination.

Examples of the inorganic filler include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, zinc borate, hydrated metal compounds such as hydrotalcite, calcium carbonate, talc, mica, mica, clay, and barium sulfate. Or they can be used in combination. The particle size of the inorganic filler is preferably in the range of 1 to 5 μm. Further, the inorganic filler preferably has an aspect ratio of 2 to 10 to improve the appearance of the foam. Inorganic fillers having such an aspect ratio are magnesium hydroxide, aluminum hydroxide, hydrated metal compounds such as calcium hydroxide,
A plate-like material such as talc, mica, mica, clay, and barium sulfate can be selected. The measurement of the aspect ratio is calculated from the ratio between the particle size and the thickness by an electron microscope. The plate-like filler can improve the smoothness of the surface state after foaming, and can improve the appearance after foaming.

The surface treatment of the inorganic filler is not particularly limited, but those treated with an alcohol, paraffin, an organic acid, an organic acid salt, a coupling agent or the like are preferably used.

In the present invention, the inorganic filler functions to reduce flame retardancy or heat of combustion. The amount of the inorganic filler added in the present invention is 70 to 1 with respect to 100 parts by weight of the resin component.
The amount is 50 parts by weight, particularly preferably 90 to 120 parts by weight. If the addition amount is less than 70 parts by weight, the flame retardancy or the decrease in the heat of combustion is insufficient, and if it exceeds 150 parts, the foaming ratio decreases and the processability also decreases.

As the foaming agent used in the present invention, a pyrolytic foaming agent can be used. For example, azodicarboxylic acid amide (AD
CA), azo compounds such as azobisisobutyronitrile (AIBN), sulfonyl hydrazide compounds such as P, P'-oxybisbenzenesulfonyl hydrazide (OBSH), dinitrosopentamethylenetetramine (DPT)
Chemical blowing agents such as nitroso compounds. These may be used alone or in combination of two or more. Among these, azodicarboxylic acid amide is preferred from the viewpoint of processability and stability.

The amount of the foaming agent to be added to the resin composition of the present invention is from 2 to 15 parts by weight based on 100 parts by weight of the resin component. If the amount is less than 2 parts by weight, a sufficient expansion ratio cannot be obtained. , More than 15 parts by weight saturates the effect. A foaming regulator is used to adjust the decomposition temperature of the foaming agent. For example, metal soaps, metal oxides, urea-based compounds, acid anhydrides, organic acids, and the like can be used alone or in combination. The amount is about 0.1 to 5 parts by weight.

The other components in the present invention are not particularly limited and can be appropriately selected. For example, antioxidants, light stabilizers, antistatic agents, pigments, flame retardants, processability improvers, lubricants, plasticizers And various additives such as metal oxides, fibers, and wood flour.

The foamable resin composition of the present invention can be mixed using a known mixing device, and examples of the mixing device include a Banbury mixer, a kneader, and an extruder. Further, the sheet can be formed using a known device, and examples thereof include a roll processing device such as a calender device, an extruder, and an inflation device. In particular, a calender device is preferable because shearing during processing is small and low-temperature processing is easy.

The foamed sheet of the present invention is obtained by forming an unfoamed sheet using the foamable resin composition, laminating the sheet with a base material, and foaming. The substrate is not particularly limited, such as paper, woven fabric, nonwoven fabric, and synthetic resin sheet.

For example, as a base material used as wallpaper, general paper and flame-retardant paper can be used. Examples of the flame-retardant paper include, for example, pulp mainly composed of self-extinguishing aluminum hydroxide, clay, kaolin, talc, flame-retardant paper mixed with titanium dioxide and the like, and those impregnated with a guanidine compound, Examples include aluminum hydroxide paper and glass fiber. The thickness of these papers is not particularly limited, but is usually 0.10 to 0.15 mm.

The foamed sheet of the present invention has a temperature of 100 ° C. to 160 ° C.
It is preferable to form an unfoamed sheet within the range described above, and this unfoamed sheet is heated to 200 ° C. to 240 ° C. to form a foamed sheet. Although the thickness of the foam sheet is not particularly limited, the thickness after foaming is usually about 0.1 to 5.0 mm. Also, the expansion ratio can be appropriately selected according to the application,
Usually, it is about 3 to 6 times.

The foamed sheet of the present invention can be subjected to primer treatment, printing such as gravure, surface treatment, etc.
These can be performed either before or after foaming. In addition, a concavo-convex pattern can be provided by embossing. Further, other layers such as a surface protective layer such as a stain prevention film can be appropriately selected and laminated as needed.

The foamed sheet of the present invention does not generate gas that pollutes the environment during combustion, has flame retardancy and dimensional stability, and is suitable for wallpaper, leather, flooring, and the like. is there.

[0028]

Next, the present invention will be described in more detail with reference to specific examples, but the present invention is not limited to these examples.

Examples 1 to 19 After the ingredients shown in Table 1 were mixed, an unfoamed sheet having a thickness of 0.2 mm was obtained using an inverted L-type calendering machine at a temperature of 140 ° C. The unfoamed sheet was heated in an oven at 210 ° C. for 60 seconds to foam, thereby obtaining a foam. The processability of the unfoamed sheet during processing, the foamed state of the foam, and the expansion ratio were measured. Table 1 shows the results.

Comparative Examples 1 to 10 For comparison, after mixing the compounding ingredients shown in Table 2, a foam was produced in the same manner as in the example, and the processability, the foaming state of the foam and the foaming ratio were measured. It was measured. The results are shown in Table 2.

Examples 20 to 25 After the ingredients shown in Table 3 were mixed, an unfoamed sheet having a thickness of 0.1 mm was obtained with a reverse L-type calender molding machine at a temperature of 140 ° C. After laminating this unfoamed sheet with 0.11 mm flame-retardant paper, it is heated in an oven at 210 ° C. for 60 seconds to be foamed, subjected to gravure printing, and embossed to obtain a three-dimensionally-designed wallpaper with high designability. Was. The processability, foaming state, expansion ratio and flame retardancy of this wallpaper were measured. Table 3 shows the results.

Comparative Examples 11 to 13 After mixing the ingredients shown in Table 3, wallpaper was prepared in the same manner as in Examples 20 to 25, and the same measurement was carried out. The results are shown in Table 3.

The components used in the examples and comparative examples are as follows, and all the blending parts are parts by weight. The ethylene vinyl acetate copolymer resin (EVA) has a MFR of 0.1% vinyl acetate containing 28% Evaflex EV-290 manufactured by Mitsui DuPont MFR = 0.8 a vinyl acetate containing 20% Ultracene UE-627 MFR = 1. 5 20% Ultra Acetate UE-631 MFR = 4.0% Vinyl Acetate 26% Ultra Acetate UE-634 MFR = 10 Vinyl Acetate 20% Ultra Acetate UE-633 MFR = 10 Tosoh Corporation

Rosin is special rosin ester Pine Crystal KE-100 Arakawa Chemical Industries, Ltd. Petroleum resin is C5 petroleum resin Quinton A-100 Nippon Zeon Co., Ltd. Polyterpene resin is YS resin PX # 1150 Yasuhara Yushi Non-crystalline α-olefin resin is Ube Tac APAO UT2780 Ube Lexen Co., Ltd. VLDPE is ultra-low density polyethylene Lumitac 53-1 MFR = 20 manufactured by Tosoh Corporation

Calcium carbonate (1) has an average particle size of 2 μm.
No aspect ratio due to irregular shape Calcium carbonate (2) average particle size = 7μ No aspect ratio due to irregular shape Aluminum hydroxide (1) Average particle size = 4μ Aspect ratio = 4 Aluminum hydroxide (2) Average particle size Diameter = 4μ Aspect ratio = 1.5 Average particle size of aluminum hydroxide (3) = 9μ Aspect ratio = 1.5 Magnesium hydroxide (1) Average particle size = 3μ Aspect ratio = 5 Magnesium hydroxide (2) Average particle size = 8μ Aspect ratio = 5

<Workability> The workability was evaluated in the calendering at a processing temperature of 140 ° C. A: Good workability. ：: Processing is possible. ×: Poor workability. <Bubble state = appearance of foam sheet> A: The surface is smooth and beautiful. ：: The surface is smooth ×: The surface is uneven. <Expansion ratio> The expansion ratio was shown as a ratio of the thickness of the sheet before foaming to the thickness of the sheet after foaming. ：: Foaming ratio 5 times or more. ：: Foaming ratio 4 times or more. Δ: Foaming ratio 3 times or more. ×: Less than 3 times the expansion ratio. <Flame retardancy> The amount of smoke (CA) and calorific value (Tdθ)
Measured according to the flame retardancy test method of the interior material and construction method of IS A1321 building. Note that CA indicates a smoke generation coefficient, and T
dθ indicates a temperature time area (° C. minute). Evaluation (judgment) A: CA is 60 or less and Tdθ is 100 or less. ×: CA exceeds 60 or Tdθ exceeds 100.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

According to the present invention, 99-80 parts by weight of an ethylene vinyl acetate copolymer resin having an MFR of 0.5-7 g / 10 min.
A tackifier or a melt viscosity at 190 ° C of 0.
Mixing one or both of amorphous non-crystalline α-olefin resin of 1 to 10 Pascal second with 1 to 20 parts by weight,
By containing 70 to 150 parts by weight of an inorganic filler and 2 to 15 parts by weight of a foaming agent with respect to 100 parts by weight of the mixture (resin), the fluidity of the resin is improved, and the processability can be improved. Excellent in workability even with high filling, good foaming properties, does not generate gas that pollutes the environment during combustion, and has flame retardancy and dimensional stability; wallpaper, leather, flooring, etc. A suitable foamable resin composition can be obtained.

The ethylene-vinyl acetate copolymer resin having an MFR of less than 0.5 g / 10 min and an MFR of less than 0.5 g / 10 min.
5 g / 10 min or more, and the weighted average MFR of the mixture is 0.5 g / 10 min ≦ Σ (M of resin
FR × resin added amount) / (total resin added amount) ≦ 7 g / 10 min.
Blended (mixed) with FR less than 0.5 g / 10 min
By doing so, the tension at the time of melting can be improved, and the workability is further improved.

The above foamable resin composition is molded into an unfoamed sheet, laminated with a substrate and foamed to form a composite, having flame retardancy and dimensional stability. A good foam sheet can be obtained, and a foam sheet suitable for, for example, wallpaper, leather, flooring, and the like can be obtained.

Further, by using a plate-like material having an aspect ratio of the inorganic filler of 2 to 10 in the foamable resin composition, smoothness of the surface state after foaming is improved, and The appearance can be improved.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kimito Teramae 5-3 Higashinakakanuki-cho, Tsuchiura-shi, Ibaraki Ronsil Industry Co., Ltd. Tsuchiura Works Technical Research Institute (56) References JP-A-5-132593 (JP, A) JP-A-10-195256 (JP, A) JP-A-7-186336 (JP, A) JP-A-10-17724 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) C08J 9/00-9/42 B32B 5/00-5/32 C08K 3/00-13/08 C08L 1/00-101/14

Claims (3)

(57) [Claims] 1. An amorphous material having an MFR of from 0.5 to 7 g / 10 min, 99 to 80 parts by weight of an ethylene vinyl acetate copolymer resin and a tackifier or a melt viscosity at 190 ° C. of from 0.1 to 10 Pascal-second. One or both of the α-olefin resins are mixed with 1 to 20 parts by weight, and 100 parts by weight of the mixture (resin) is mixed with the inorganic filler 70 to 15 parts.
A foamable resin composition comprising 0 parts by weight and 2 to 15 parts by weight of a foaming agent. 2. The method according to claim 1, wherein the ethylene-vinyl acetate copolymer resin is M
FR less than 0.5 g / 10 minutes and MFR 0.5 g /
10 minutes or more, and the weighted average MFR of the mixture is 0.5 g / 10 minutes ≦ Σ (MFR of resin ×
The foamable resin composition according to claim 1, wherein the amount of the resin added) / (the total amount of the resin added) ≤ 7 g / 10 minutes. 3. A foamed sheet obtained by molding the foamable resin composition according to claim 1 or 2 into a sheet, laminating it with a substrate, and foaming the same.