JPS60101030A - Foamed sheet and preparation thereof - Google Patents

Abstract

PURPOSE:To obtain a foamed sheet showing excellence in design and durability as an ornamental sheet by a method wherein a plastisol prepared by dispersing methacrylate resin in a plasticizer for vinyl chloride resin is applied partially on a foamable soft vinyl chloride resin layer and then heated. CONSTITUTION:After a foamable PVC layer 2 is formed on a substrate 1, a plastisol prepared by dispersing methacrylate resin in a plasticizer for PVC neither dissolving nor swelling this resin is applied on a part of said layer in which a projection is desired to be formed. The plasticizer in the plastisol migrates into the foamable PVC layer 2 in the part 4 coated with the plastisol, and as the result, this part 4 obtains a higher foaming ratio faster than the other part. Consequently, the projection can be formed therein, and further a methacrylate resin protection layer 4' strengthened by the separation of the plasticizer from the resin in the plastisol is formed on the surface of the projection.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foamed decorative sheet made of chloride and di-A111 resin (hereinafter referred to as PVC) useful as a covering material for wall coverings and the like having excellent design and durability, and a method for producing the same. .

It is widely prized for its decorative sort minerals, which are made by forming a PVC-based resin layer on a base material such as paper or cloth, and giving it variations in color, shape, gloss, etc., wall covering materials, flooring materials, etc. ing. especially,
The use of foamed 41M resin is increasing because of its excellent design depth, flexibility, and flexibility as a base material.

So far, known methods for producing decorative foam sheets include: 1. The so-called mechanical embossing method, in which the sheet before or after foaming is embossed with heat and pressure to create mechanical irregularities; The sol is partially applied onto the substrate or onto the foamed or non-foamed resin layer formed on the substrate using a rotary screen, an intaglio, or the like.

1-foam printing method that heats and foams this to obtain a molded product; 1) An ink layer containing an agent that suppresses or promotes foaming, a crosslinking agent, etc. is printed on a foamable resin layer containing a foaming agent, and then this is foamed. There is a chemical embossing method for producing molded products; a wrinkled foaming method that forms irregular wrinkled foams due to the difference in heat meltability between the upper and lower layers; these methods are used to manufacture a wide variety of decorative sheets. It is put into practical use.

And the design quality of the foam decorative sheet produced by these methods, Ti! It is known that it is effective to increase the foaming ratio in order to improve properties such as ti feel and smoothness without increasing the 3JIF of the sheet.However, when the foaming ratio is increased commercially, , the strength of the foamed part is significantly reduced, especially the mechanical strength of the surface of the convex part, so the foaming ratio should be lowered to a range that can maintain practical strength, or
Protection on the entire surface of the t3 foam layer? The method of forming 4 and holding strong #all is used.

In addition, since decorative sheets, wall coverings, furniture, etc. are generally used for a relatively long period of time, there may be discoloration during this period.
Measures must be taken to prevent stains, and for this reason conventionally the entire surface of the sheet is coated with an acrylic resin-PVC surface treatment agent or non-foamed vinyl plastisol.
However, the effects and sustainability of these methods have been insufficient, and they have imposed limitations on designs and led to an increase in the number of steps.

As a result of repeated studies to obtain a foamed sheet with excellent design and strength, the inventors of the present invention have added fine powder of methacrylate resin to a foamable soft PVC layer on a PVC layer that does not dissolve or swell the resin. Apply Glastisol uniformly dispersed in a plasticizer to the area where you want to form a convex part.

As a result of the transfer of the floodable agent in the plastisol to the foamable P'vO/ij of the plastisol-applied area, the melt viscosity of the foamable PVA in that area is lower than in other areas, so that heating causes this area to react more quickly. In order to reach the foaming ratio more quickly, convex portions can be formed, and a strong molten film is formed on the surface of the core convex portions, where the plasticizer is removed from the resin in the plastisol. The convex surface is
The present invention was completed based on the discovery that the material has no holes or irregularities, is resistant to stains, and can be easily damaged by friction from hands, cloth, etc., and exhibits excellent design and durability as a loading sheet. I ended up doing it.

That is, the present invention 1j: consists of a 111 base material, a soft vinyl chloride resin foam layer formed thereon, and a protective layer obtained from a methacrylate resin plastisol that covers all or part of the convex portions of this foam layer. and (2) a foamed packaging sheet characterized in that the foamed layer portion covered with the protective layer has a higher content ratio of stabilizer (to vinyl chloride resin) than the other foamed 1t31 layered portions; After forming a foamable soft vinyl chloride resin layer on the resin, partially apply Glastisol, which is a mixture of methacrylate resin dispersed in a BI agent for vinyl chloride resin that does not dissolve or swell the resin. The present invention provides a method for producing a foamed sheet, characterized in that the foamed sheet is heated and then heated to produce a foamed sheet in which the Glastinol-applied portion becomes a convex portion.

In the present invention, the methacrylate resin used is a homopolymer of methyl methacrylate or a copolymer of methyl methacrylate containing 70% by weight or more of polymethyl methacrylate and an unsaturated compound copolymerizable with it. Polymers with a composition that is compatible with PVE are used alone or in combination with other resins. Examples of unsaturated compounds copolymerizable with methyl methacrylate include acrylic acid. , unsaturated carboxylic acids and their esters such as methacrylic acid; unsaturated nitrites such as acrylonitrile, methacrylaterile, and chloroacrylonitrile; unsaturated amides such as acrylamide, N-methylolacrylamide, and 2-acrylamido-2-methylpropanesulfonic acid; styrene , P-, l-methylstyrene, chlorstyrene, α-methylstyrene, and other aromatic vinyl compounds; Carboxylic acid conductor 1 For example, maleic anhydride, maleic he diethyl, maleic acid mo/me f#, maleic &l'-2
-Hydroxyethyl, itaconate monomegul, itaconic acid methylamide, N-methylmaleimide, 14-P-
Examples include hydroxyphenylmaleimide.

These methacrylate resins usually have a weight average molecular weight of 40. fJ 00 or more, and the particle size in the plastisol dispersed in the PVA plasticizer is 50 μm or less, preferably 10 μm or less. If the molecular weight is less than 40,000, the plasticizer will migrate to the foamed layer and the layer will not have sufficient strength after being melt-formed. Furthermore, methacrylate resins containing gel components that are insoluble in tetrahydrofuran are also unnecessary, but in this case, the amount of gel components should be suppressed to 50% or less.

As the flocculant for PVO, which is to serve as a dispersion medium for the methacrylate resin, one is selected that is liquid at room temperature and does not cause the methacrylate resin to be dispersed to bulge or swell. An example of this is described in "Practical Handbook of Additives for Plastics and Rubber" published by Mori, Kagaku Kogyosha on August 10, 1971, pages 52 to 55. The type of plasticizer should be carefully selected, especially depending on the composition of the methacrylate resin used. for example.

When using methyl methacrylate homopolymer, plasticizers with strong dissolving power such as diptyl phthalate and butyl benzyl phthalate are unsuitable because they cause the methacrylate resin to swell. S such as long-chain alkyl esters of heptallic acid such as butyl lauryl acid and alkyl esters of aliphatic dibasic acids such as dioctyl adipate and dioctyl sepatate.
Plasticizers with a P value of less than 9.1 are suitable in this case.

On the other hand, when using a methacrylate copolymer containing acrylonitrile as a copolymerization component, it may be possible to use a plasticizer with stronger dissolving power.

The amount of plasticizer to be used may be within the range 4 so that the methacrylate resin becomes plastisol.

Although not particularly limited, it is generally 40 to 1.000 parts by weight per 100 parts by weight of resin.

The methacrylate resin plastisol used in the present invention contains a compound that can cause crosslinking when heated, thereby crosslinking the methacrylate resin layer on the surface of the convex portion and improving heat resistance and durability. For example, polyfunctional acrylate compounds such as trimethylolpropane trimethacrylate and polyethylene glycol diacrylate, or polyfunctional allyl compounds such as diallyl phthalate and triallyl triisocyanurate, dicumyl peroxide, A masked isocyanate compound can be used in combination with a radical generator such as benzoyl peroxide, or in combination with a polyol such as polyenalene adipate, polytetrahydrofuran, or polycaprolactone.

Furthermore, methacrylate resins produced using polymerizable compounds having functional groups that react with incyanate, such as 2-hydroxyethyl acrylate, glycidyl acrylate, and 2-aminoether acrylate, as copolymerization components produce incyanate when heated. It is also possible to coexist with a masked isocyanated metal material such as the one described above.

In addition, if the blowing agent in the 5-expandable PVC layer is a chemical blowing agent that generates gas when heated, the plastisol of methacrylate resin may contain a compound that promotes the foaming of the chemical blowing agent. This is effective in widening the difference in unevenness of the sheet after heating and foaming and improving the design. Examples of these accelerators include urea, zinc oxide, zinc octylate, lead phthalate, cadmium stearate, and the like.

In addition, it is also possible to mix into the methacrylate-based 1fIA fat gelastesol, if necessary, compounds commonly used as plastic compounding agents, such as a filler 1 colorant, a flame retardant, a stabilizer, and an ultraviolet absorber.

On the other hand, the first foamable soft PVC layer is made of PVO as a main component, mixed with a fusible agent, a stabilizer, a foaming agent, and if necessary, a coloring agent, a filler, a flame release agent, and the like.

As the PVC, a normal homopolymer of vinyl chloride or a copolymer having a vinyl chloride component of 70 times Jt, t% or more and a degree of polymerization of 500 to 3,000 is used. In addition, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid ester copolymer, etc. can also be used in combination. As blowing agents, chemical blowing agents such as azobisisobutyronitrile, azodicarbonamide, paratoluenesulfonyl semicarbazide, dinitrosopentamethylenetetramine, paratoluenesulfonylhydrazide, 4,4'-oxybisbenzenesulfonylhydrazide, and sodium bicarbonate; Heat-expanded capsules such as liquefied gas microcapsules can be used.

Formation of a foamable PVE layer on paper, cloth, asbestos, etc. may be carried out using a conventional method such as a wire, knife coater, rod coater, gravure coater, or screen coater.

In addition, methacrylate resin plastisol can be used as a foamable PV
Screen printing is preferred as a method for forming the film on the e-waste because it allows for a relatively thick coating, but there is no limitation to other methods as long as the film can be partially coated.

Furthermore, it is also effective to apply a methacrylate resin plastisol selectively to the convex portions or concave portions of the foamed PvCrf4 by forming concavities and convexities in advance using a mechanical means such as an engraving roll. Furthermore, before coating this plastisol, surface treatment printing, pattern printing, or flocking may be performed on the entire or partial foamable PVA layer.
After applying plastisol of methacrylate resin, a sheet with an uneven pattern can be obtained by heating and foaming the sheet in a conventional device such as a hot air circulation furnace or a hot wire furnace.

This is then subjected to high-level processing such as embossing, printing, and flocking to produce a product decorative sheet.

In the decorative sheet obtained in this way, the high-base foam portion is covered with a strong methacrylate thread resin layer, and the foam layer below is soft and has mass heat, and is lightweight yet strong and stain-resistant. .

It has characteristics not found in conventional decorative sheets.

The present invention will be explained below with reference to Examples. Note that the number of copies used for each component is based on uM f1.

Example 1 (See Figures 1 and 2) Plastisol of the following composition was applied to a thickness of about 200μ on flame-retardant paper 1, and heated at 140C for 1 minute to decompose the azodicarbonamide. A gelatinized foamable sheet 2 was obtained in a non-containing state.

Polyvinyl chloride for plastisol 100 (degree of polymerization 1,
500) Di-2-ethylhexyl phthalate 60 Heavy calcium carbonate 50 Azodicarbonamide 6 Na-Zn stabilizer 5 Nathane oxide 10 Mineral turpentine 5 Next, the base printing ink was applied to the gelled foam sheet by lavia printing. Next, on this foamable sheet, a methacrylate resin plastisol 4 having a thickness of about 100 μm having the following composition was applied by screen printing (Fig. 1), heated and foamed at 210C for 90 seconds, and then A foam decorative sheet as shown in Figure 2 was obtained.

Polymethyl methacrylate 100 (particle size 0.15μ average molecular weight 600,000) G2-
Ethylhexyl phthalate 400 Titanium oxide 10 Fluorescent colorant 0.1 Silicic anhydride 5 The plastisol having the above composition excludes 200 parts of di-2-ethylhexyl phthalate.

The mixture was dispersed and mixed in a three-roll mill, and then diluted with 200 parts of di-2-ethylhexyl phthalate that had been removed.

Example 2 (see Figures 3 and 4) Base printing ink 5 was applied to the entire surface of the same foamable sheet 2 as used in Example 1 using a gravure stamping machine, and after drying, foaming was performed in an infrared heating oven. After heating to a temperature that does not decompose the foaming agent in the sheet, an embossing roll is used to create an uneven pattern, and at the same time, valley stain printing is performed.7 Plastisol 7 having the following composition is applied on this sheet.31Qj ) and 210 rpm for 90 seconds to obtain a foamed decorative sheet as shown in FIG.

Methyl methacrylate/ethyl acrylate/100
Acrylonitrile-88/8/4 copolymer (particle size 0
．． 24 μ average molecule @ i, aoo, ooo) di-2-ethylhexyl phthalate) 400 silicic anhydride 5 Comparative example 1 Polychloride for plastisol with a degree of 1,600 of polymethyl methacrylate of the methacrylate resin plastisol used in Example 1 A foamed sheet was obtained in the same manner as in Example 1 except that vinyl was used.

Comparative Example 2 A non-conventional example in which the polymethyl methacrylate of the methacrylate resin gelastesol used in Example 1 was changed to a composite of methyl methacrylate/butyl methacrylate = 50150 (average molecular weight sao, ooo average particle size 0.15μ) An attempt was made to obtain a foamed sheet using the same procedure as in 1, but the viscosity of the plastisol increased significantly and coating around the PVE was not possible.

Comparative Example 3 A foamed sheet was obtained in the same manner as in Example 1 except that di-2-ethylhexyl phthalate in the methacrylate resin plastisol used in Example 1 was changed to butylbenzyl phthalate. It solidified after one day, making it impossible to coat.

Comparative Example 4 (see Figure 5) The same foamable sheet used in Example 1 was coated with polymethyl methacrylate solution type surface treatment agent 8 using a gravure printing machine, foamed at 210C, and then immediately At the same time as an embossing roll was used to create an uneven pattern, valley stain printing was performed to obtain a foamed sheet (Fig. 5).

Example 3 (See Figures 6 and 7) Asbestos substrate 10 was coated with plastisol having the following composition to a thickness of 300 μm and heated at a temperature at which the foaming agent 1 did not decompose to solidify, thereby obtaining foamable sheet 11.

Polyvinyl chloride for plastisol 60 (degree of polymerization 1.!100) Polyvinyl chloride for thinning plastisol 40 (degree of polymerization 1.!100)
000 Average particle size 40μ) Di-IL-octyl phthalate 52 Ba-Zn liquid stabilizer 3 Azodicarbonamide 3 Titanium oxide 5 Mineral turpentine 10 Colored ink 12 containing polymethyl methacrylate as the main vehicle was printed on the sheet 11 and dried. After that, Plastinol 16 having the following composition was coated and foamed by heating at 210C for 2 minutes to obtain a 5[3-fold sheet (Fig. 7).

Methyl methacrylate/1 (-methylol acrylic 1
00 amide-80/20 copolymer (average molecular weight 1.20
0,000 Average particle size 02μ) dinonyl phthalate
450 Feldspar fine powder 4゜Example 4 (see Figures 8 and 9) After obtaining foamability 7-) 11 in the same manner as in Example 3, irregularities were formed on the sheet with an engraving roll, and the convex portions were Plastisol 14 having the following composition was coated and heated at 130C for 2 minutes to transfer the plasticizer in the plastisol to the foamable sheet layer.

Methyl methacrylate/α-methylstyrene/100
Acrylonitrile-85/10/5 copolymer (average molecular weight 79 to 000 average particle size 1,2μ) dioctyl adipate 15° di-2-ethylhexyl phthalate 150 red pigment
3 Next, plastisol 15 having the following composition was coated using a rod coater (Fig. 8) and heated at -210C for 2 minutes to obtain a foamed sheet (Fig. 9).

Polyvinyl chloride for plastisol 70 (degree of polymerization 1.800) Polyvinyl chloride for thinning gelastenol 30 (degree of polymerization 1
．． ooo) Di-2-ethylhexyl phthalate 45Ba-2n stabilizer 3 Comparative example 5 The particle size of the methacrylate resin in Glastidal was set to 200
A foamed sheet was obtained by carrying out the same operation as in Example 6 except that μ was used.

Comparative Example 6 The molecular weight of the methacrylate resin in plastisol was
, 000 was carried out in the same manner as in Example 4 to obtain a foamed sheet.

Comparative Example 7 (See Figure 10.11) After obtaining a foamable sheet 11 in the same manner as in Example 6, a foaming suppressing ink 16 containing a compound that suppresses the decomposition of a foaming agent is partially thermally transferred onto the top of the foaming sheet 11. μ.

Thereafter, the same pva plastisol 1 used in Example 4 was added.
5 was coated on the entire surface (10th part, 1) and heated at 210C for 3 minutes to form a +B curved 7-t with an uneven pattern (Fig. 11).
I got it.

The characteristics of the 'A pond/-t obtained in the above Examples and Comparative Examples were evaluated and the results shown in Table 1 were obtained. The meaning of each test item in Table 1 is as follows.

Blocking property: The convex parts of a 1010 x 10 square sample were placed face to face, a 5001 weight was placed on top of this through a steel sheet of I Im thickness, and after being left at 60C ± 2C for one week, the joint surface was The force required for peeling is measured using a tack tester.

Durability: The foam sheet was fixed on a sample mount tilted at 45° to the vertical direction, and 1 oaIc9 of sand was dropped from a hopper 2 m above, and the extent of damage to the surface of the foam sheet was visually observed.

Three stages: ○Δ× in order of least damage Evaluate with.

Antifouling property: Attach a black rubber piece to the rolling surface of the driving wheel of the taper set abrasion tester and apply a load to the sample surface. After rolling for 1,000 revolutions, the dirt on the transfer surface of the sample is visually observed and evaluated on a three-grade scale of ○△X in descending order of dirtiness. The color of the sample after arc emission for 000 hours (○△× in order of least discoloration) 1 The cracks on the surface (0△× in order of least) are evaluated.

[Brief explanation of drawings]

Figure 1 shows the sheet of Example 1 before foaming, Figure 2 shows the sheet after development, Figure 3 shows the sheet of Example 2 before foaming, and Figure 4 shows the sheet after foaming. , and FIG. 5 shows comparative example 4.
Figure 6 shows the sheet of Example 60 before foaming, Figure 7 shows the sheet after foaming, and Figure 8 shows the sheet of Example 4 before foaming. FIG. 9 shows the sheet 7 after foaming, FIG. 10 shows the sheet of Comparative Example 7 before foaming, and FIG. 11 shows cross-sectional views of the sheet after foaming. 1.10・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・… Foaming soft p v a ) @2
', 11'... Soft PVA foam layer 3, 5.6.
9.12...Printing ink 4.7, 13.14
...Methacrylate resin Plastinle 4',
7', 15', 14'...Methacrylate lilywood protective layer 8...Polymethyl methacrylate bath liquid type surface treatment agent 15...PvC plasticity 15'... ...11 people in PVA preservation layer W1 Excerpt from Nippon Zeon Co., Ltd. 1 [N1
Figure 2: p: (1=II Ur 4 1 Tsu 1 n r1 5 1
]1 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11

Claims (1)

[Claims] A protective layer obtained from a fil base material, a soft vinyl chloride paulownia resin foam layer formed thereon, and a methacrylate resin plastisol covering all or part of the convex portions of the foam layer. , and the foam layer portion corrugated by this protective layer has a higher hJk! than other foam layer portions. A foam sheet characterized by a high content ratio of J agent (to vinyl chloride resin'). (2) After forming a foamable soft vinyl chloride resin layer on the base material, a methacrylate resin is dispersed on this layer in this resin f: a plasticizer for vinyl chloride resin that does not cause bath dissolution or mineral expansion. 1. A method for producing a foam sheet, which comprises partially applying plastisol and then heating the foam sheet to form a foam sheet in which the plastisol-applied portion becomes a convex portion.