JPH09151287A - Polyvinyl chloride sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyvinyl chloride sheet which does not undergo a severe initial-stage discoloration and has an improved persistence of heat resistance by sheeting a compsn. comprising a polyvinyl chloride resin, a calcium compd., a zinc compd., and a specific hydrotalcite compd. SOLUTION: A compsn. comprising 100 pts.wt. vinyl chlorie resin having an average degree of polymn. of 500-1,000, 0.01-2 pts.wt. calcium compd., 0.01-2 pts.wt. zinc compd., 0.01-5 pts.wt. hydrotalcite compd. represented by the formula (W, X, Y, and Z satisfy the relations: 2W+3X=Y+2Z and 2<=W<=6; and 2<=m<=4), and if necessary 0.1-5 pts.wt. epoxidized vegetable oil, 0.01-2 pts.wt. mono-, di-, or triglyceride of a higher fatty acid, and 0.01-1 pt.wt. β-diketone compd. is sheeted, thus giving a polyvinyl chloride sheet having a thickness of 0.05-1mm and a softening point (JIS K 6734) of 50-80 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION A vinyl chloride resin sheet is a general-purpose resin and is well-balanced in comparison with other resins in terms of low manufacturing cost, good characteristics, good workability, etc. It is processed into various shapes and used as packaging material for foods and pharmaceuticals.

[0002]

2. Description of the Related Art A halogen-containing resin such as a vinyl chloride resin is liable to undergo thermal decomposition mainly due to dehydrohalogenation during heat molding processing, which causes deterioration of mechanical properties of processed products. Color tone is deteriorated, resulting in a significant disadvantage. In order to avoid such disadvantages, it is necessary to add one or several kinds of heat stabilizers to the synthetic resin to suppress deterioration in the processing step. For this purpose, a combination of lead, cadmium, barium, zinc and other metal compounds,
A heat stabilizer added with an organic phosphite ester, a phenol compound, and an epoxy compound has been used. However, cadmium, lead, and barium metals are highly toxic, causing various problems such as waste treatment after use. Therefore, cadmium, lead, a thermal stabilizer obtained by adding an organic phosphite ester, a phenolic compound, an epoxy compound to a combination of calcium-zinc metal compounds that does not use a metal compound stabilizer of barium metal has been used. However, cadmium, lead, and barium-based metal compounds have thermal decomposition caused by dehydrohalogenation, heat resistance persistence due to this, and initial coloration (a phenomenon in which initial coloring occurs during thermal history during processing). There is a major drawback that it is inferior to the stabilizer containing the stabilizer.

In order to solve these drawbacks, a β-diketone compound represented by the following general formula is used as a heat stabilizer for calcium-zinc-based metal compound stabilizers, especially as an initial color-preventing agent, to improve the effect. It is (Japanese public Sho 52-479)
48). R-CO-CHX-CO-R (In the formula, X is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and R is an alkyl group or an aryl group.) The combination of calcium-zinc-based metal compound stabilizers and other organic phosphite esters, epoxidized compounds, and stabilizing aids for diketone compounds alone causes insufficient thermal stability, resulting in heat resistance persistence and initial color prevention. Inferiority, because the thermal decomposition product of vinyl chloride resin was mixed in the product or the hue of the product deteriorated and it caused a big hindrance to the production, it must have a certain degree of thermal stability as a formulation that can be compatible with recent equipment. .

Calcium compounds are used because they have the effect of not thermally decomposing for a long period of time, and zinc compounds are used because they have the effect of causing little initial coloration. However, calcium compounds have a problem that initial coloring is strong, and zinc compounds must be used together to prevent initial coloring. However, when zinc compounds are contained, rapid thermal decomposition called zinc burning is called zinc burning. Occurred, and there was a problem that the heat resistance persistence deteriorates due to blackening and decomposition in a short time. The problem of zinc burning is polyhydric alcohol such as mannitol, sorbitol, pentaerythritol, dipentaerythritol, hydrotalcite, zeolite, oxide (calcium, magnesium), hydroxide (calcium, magnesium).
It is solved by adding a costabilizer represented by an inorganic salt such as. However, the stabilization time of the polyhydric alcohol substance is relatively short, and the zinc compound added for preventing the initial coloration tends to be incorporated into the structure to deteriorate the initial coloration. In addition, the addition of costabilizers typified by inorganic salts causes the problem of whitening of the product. The hydrotalcite compound having a specific crystal structure is used as a stabilizer for a halogen-containing resin. Hydrotalcite compounds capture hydrogen chloride generated by thermal decomposition of vinyl chloride resin,
It has a neutralizing effect as a stabilizing effect, and is effective in combination with a calcium-zinc stabilizer. The vinyl chloride resin sheet is produced by calender rolling, and a higher fatty acid compound such as stearic acid or lauric acid is mainly used as a lubricant to be added. However, since the higher fatty acid compound is an acid-based lubricant having a carboxylic acid group, the hydrotalcite compound reacts with the carboxylic acid, and the resulting magnesium soap compound is colored red, or the hydrochloric acid scavenging effect is lost and the initial coloring occurs. There was a drawback that it became worse.

[0005]

PROBLEM TO BE SOLVED BY THE INVENTION To provide a vinyl chloride sheet capable of coping with an increase in the size and speed of production equipment, with improved heat resistance durability and without deterioration of initial coloring.

[0006]

DISCLOSURE OF THE INVENTION According to the present invention, a calcium compound of 0.01 to 2 is added to 100 parts by weight of a vinyl chloride resin.
Parts by weight, 0.01 to 2 parts by weight of the zinc compound, the general formula [M
g _W · Al _X · (OH) _Y · (CO ₃ ) _Z ] mH ₂ O (W, X,
Y and Z are positive numbers satisfying 2W + 3X = Y + 2Z, and W is 2
≦ W ≦ 6, m is a positive number and is composed of a composition in which 0.01 to 5 parts by weight of the hydrotalcite compound represented by 2 ≦ m ≦ 4) is added, or the composition is epoxidized vegetable oil 0.
1 to 5 parts by weight, a β-diketone compound 0.01 to 1 part by weight, and an ester compound 0.01 to 2 parts by weight, and the vinyl chloride resin preferably has an average degree of polymerization of 500 to 1000. The softening temperature of the vinyl chloride sheet is 50 to 80 ° C. as measured by the softening temperature test of JIS K6734, and the ester compound is composed of a monovalent to trivalent ester compound consisting of glycerin and a higher fatty acid, and the sheet thickness Is a vinyl chloride sheet having a thickness of 0.05 to 1 mm.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The vinyl chloride resin of the present invention has an average degree of polymerization of 500 to 1000. If the average degree of polymerization is less than 500, the melt viscosity becomes low, the stiffness of the sheet decreases, and the calendar processability deteriorates. On the other hand, when the average degree of polymerization exceeds 1,000, the melt viscosity becomes high and a high temperature is required during calendering, which hinders the production of the sheet. As the calcium compound, carbonate, silicate,
C such as glycerophosphate, acetate, propionate, heptanoate, 2-ethylhexylate and stearate
Higher fatty acid salts of up to ₈ -C _22, 12-hydroxy stearate, lactate, citrate, gluconate, sorbate, rosin acid salts, ethyl acetoacetate, benzoate, isodecane salt, neodecanoic Acid salt, naphthenate,
Hydroxide and the like. An appropriate amount of calcium compound added is 0.01 to 2 parts by weight per 100 parts by weight of the vinyl chloride resin. More preferably, it is 0.05 to 1 part by weight. If the addition amount is 0.01 parts by weight or less, Zn burning occurs and the thermal stability is deteriorated, and if it is 2 parts by weight or more, initial coloring is deteriorated.

Organic compounds of zinc include carbonates, orthophosphates, heptanoates, 2-ethylhexylates,
Higher fatty acid salt to C ₈ -C ₂₂ such as stearic acid salts, rosin acid salts, dibutyl dithiocarbamates, salicylates, isodecanoate, neodecanoate, naphthenate salts. Addition amount of zinc compound is vinyl chloride resin 10
0.01 to 2 parts by weight is suitable for 0 parts by weight. More preferably, it is 0.05 to 1 part by weight. If the addition amount is 0.01 parts by weight or less, the initial coloration is bad, and if it is 2 parts by weight or more, zinc burning occurs rapidly and the thermal stability is deteriorated.

Hydrotalcite compounds have the general formula [Mg
_W・ Al _X・ (OH) _Y・ (CO ₃ ) _Z ] mH ₂ O (however, W,
X, Y and Z are positive numbers that satisfy 2W + 3X = Y + 2Z and W
Is represented by 2 ≦ W ≦ 6, m is a positive number and represented by 2 ≦ m ≦ 4), and is generally represented by the formula [Mg ₆ · Al ₂ · (OH) ₁₆ · (C
O ₃ )] 2H ₂ O magnesium hydrotalcite compound is used. The hydrotalcite compound may be a natural product or a synthetic product. As the synthesis method, for example, Japanese Examined Patent Publication Nos. 46-2280 and 50
Known methods in No. -3039, No. 51-29129 and the like can be exemplified. The hydrotalcites in the present invention can be used without any limitation on the particle size, and the surface thereof may be coated with higher fatty acid such as stearic acid, higher fatty acid amide, higher fatty acid ester or wax. The amount of the hydrotalcite compound added is 0.01 to 5 parts by weight, preferably 0.1 to 1 part by weight, based on 100 parts by weight of the vinyl chloride resin. If the amount is less than 0.01 part by weight, the effect cannot be seen, and if the amount exceeds 5 parts by weight, the performance is not improved so much that the appearance is deteriorated due to foaming and the mechanical strength is lowered.

Epoxidized vegetable oils can be added to the compositions of the present invention. As the epoxidized vegetable oil, epoxidized linseed oil, epoxidized soybean oil, epoxidized castor oil, epoxidized safflower oil, epoxidized linseed oil fatty acid butyl, octyl epoxystearate, 3- (2-
Xenoxy) -1,2-epoxypropane, epoxidized polybutadiene, epoxy-2-hydrohexyl hexahydrophthalate, epoxy hexahydrophthalate di-n-
Octyl and the like can be mentioned. An appropriate amount of the epoxidized vegetable oil is 0.1 to 5 parts by weight based on 100 parts by weight of the vinyl chloride resin. If the amount is less than 0.1 parts by weight, the fluidity of PVC deteriorates and the calendar processability is impaired. When the amount is 5 parts by weight or more, the softening temperature of the sheet is lowered, and the rigidity of the obtained sheet is lowered, which causes problems of sheet formability and processability.

An organic phosphite compound can be added to the composition of the present invention. Examples of the organic phosphite compound include tris (nonylphenyl) phosphite,
2-tert-butyl-α (3-tert-butyl-4
-Hydroxyphenyl) p-cumenylbis (p-nonylphenyl) phosphite, 4'4-isopropylidene-
Diphenol alkyl (C ₁₂ ~C ₁₅₎ phosphite. A β-diketone compound can be added to the composition of the present invention. The addition amount of the β-diketone compound is suitably from 0.01 to 1 part by weight based on 100 parts by weight of the vinyl chloride resin. If the addition amount is 0.01 part by weight or less, the desired initial coloration preventing effect is not obtained, and if the addition amount is 1 part by weight or more, the effect of improving the addition by increasing the amount is lost. An ultraviolet absorber can be added to the composition of the present invention for the purpose of improving photostability and preventing photodegradation of the contents. These include benzophenone series, benzotriazole series, salicylate series, substituted acrylonitrile series, various metal salts or metal chelates, especially nickel or chromium salts or chelates, triazine series, and piperidine series.

The composition of the present invention is sunk between PVC molecules, weakens the intermolecular force of PVC, lowers the heating temperature to increase the fluidity, and at the same time lowers the second-order transition temperature to cause micro-Brownian motion of PVC molecular segments. In order to obtain a flexible elastic gel, a plasticizer which is usually used as an additive for vinyl chloride resins can be added. Examples of the plasticizer include phthalic acid ester compounds, aliphatic dibasic acid ester compounds, phosphoric acid ester compounds, hydroxy polyvalent carboxylic acid ester compounds, fatty acid ester compounds, polyhydric alcohol ester compounds and polyester compounds. The vinyl chloride sheet of the present invention is manufactured mainly by a calendar rolling method, and an ester compound is used as a lubricant to be added. The ester compound is a compound having an ester bond between a long-chain fatty acid and an alcohol.
Fatty acids include long-chain saturated and unsaturated monocarboxylic acids, dicarboxylic acids, oxycarboxylic acids, and the like, and alcohols include monohydric alcohols such as butanol and octanol and polyhydric alcohols such as ethylene glycol, glycerin, pentaerythritol, and sorbitol. There are alcohols and many ester-based compounds are made with a combination of acid and alcohol.

The ester compound used in the present invention must be one in which all of its carboxylic acid groups react with alcohol to form an ester bond. This is because if there is an unreacted carboxylic acid group, the hydrotalcite compound reacts with the carboxylic acid, the resulting magnesium soap compound is colored red, and the effect of capturing hydrochloric acid is lost, resulting in poor initial coloring. The ester compound used in the present invention is preferably a mono- to tri-valent ester compound of glycerin and a fatty acid. Lubricants, glyceryl palmitate lubricants and the like. The amount of the ester compound added is 0.01 to 2 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. If it is less than 0.01 part by weight, there is a problem in calendering workability, and if it exceeds 2 parts by weight, slipperiness becomes excessive and a sheet having a good appearance cannot be obtained.

The vinyl chloride sheet of the present invention is JIS K6.
According to the flexible temperature test shown in 734, that is, the measurement by the Crushberg flexible temperature measuring device, the flexible temperature is from 50 ° C to 8 ° C.
0 ° C. Furthermore, 55-70 degreeC is preferable. The higher the softening temperature, the less the heat resistance, that is, the change in the appearance when heated, but if it exceeds 80 ° C., there will be problems in calendering workability and moldability in the subsequent process. If it is less than 50 ° C., the heat resistance is poor, and when heat is applied, the change in appearance becomes large, and the formability of the subsequent steps becomes a problem. The vinyl chloride sheet of the present invention has a thickness of 0.05 to 1 mm. If the thickness of the sheet is less than 0.05 mm, it cannot be used because the moisture resistance to the package contents, the gas barrier property and the strength as a package are insufficient. On the other hand, if it exceeds 1 mm, the sheet strength is so strong that handling in the subsequent process becomes difficult, and the sheet cannot be used. Further, if necessary, for example, a lubricant, a cross-linking agent, a pigment, a filler, a foaming agent, an antistatic agent, an antifogging agent,
A plate-out prevention agent, a surface treatment agent, a processing aid, a release agent, a reinforcing agent, etc. can be included.

[0015]

The present invention will be described in detail below with reference to examples. Each measurement item in the examples was measured by the following method. (1) Initial Coloring The obtained sheet was preheated to a thickness of 1 mm at 180 ° C. for 3 minutes and then pressurized at a pressure of 100 kg / cm ² for 2 minutes to prepare an initial colored plate. The yellowness (b value) of the initial colored plate was measured with a color difference meter. (2) Heat resistance stability (blackening time) The sheet was placed in a gear type aging tester set at 180 ° C., and samples were taken out every 10 minutes, and the time (minutes) until browning or blackening was measured. (3) Calender processability During sheet kneading, the sheet releasability and stains on the roll such as bleed and bloom were visually observed. ○ is good, ×
Was a problem in terms of bleeding. (4) Soft temperature Measured according to JIS K6734. (5) Secondary workability Molded by a hot platen pressure molding machine with a plug. Molding shape,
The feeding of the sheet after molding was visually observed. ○ is good,
In the case of ×, there was a problem in the shape of molding.

<Examples 1 to 7> 100 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 700 was mixed with each additive shown in Table 1 and kneaded between two rolls at 155 ° C for 3 minutes, and then 140 ° C.
It was pressed for 2 minutes to obtain a sheet (thickness 0.35 mm). <Example 8> Polyvinyl chloride resin 1 having an average degree of polymerization of 700
Each of the additives shown in Table 1 was added to 00 parts by weight, kneaded between two rolls at 155 ° C for 3 minutes, and then pressed at 140 ° C for 2 minutes to obtain a sheet (thickness 0.7 mm).

<Comparative Examples 1 to 12> 100 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 700 was mixed with the additives shown in Tables 2 and 3 and kneaded between two rolls at 155 ° C. for 3 minutes. Sheets (thickness 0.35m
m). <Comparative Example 13> 100 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 300 was mixed with each additive shown in Table 3 at 155 ° C.
After being kneaded between the two rolls for 3 minutes, and pressed at 140 ° C. for 2 minutes, a sheet (thickness 0.35 mm) was obtained. <Comparative Example 14> Each of the additives shown in Table 3 was added to 100 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 1300 to give 155
After kneading for 3 minutes between two rolls at 0 ° C., it was pressed at 140 ° C. for 2 minutes to obtain a sheet (thickness 0.35 mm). <Comparative Example 15> 100 parts by weight of a polyvinyl chloride resin having an average degree of polymerization of 700 was blended with each additive shown in Table 3 at 155 ° C.
After being kneaded between the two rolls for 3 minutes, and pressed at 140 ° C. for 2 minutes, a sheet (thickness 0.03 mm) was obtained. <Comparative Example 16> Polyvinyl chloride 10 having an average degree of polymerization of 700
Add 0 parts by weight of each additive shown in Table 3 to 2 at 155 ° C.
After kneading for 3 minutes between the main rolls and pressing at 140 ° C. for 2 minutes, a sheet (thickness 1.5 mm) was obtained. The measurement results of each example are shown in Table 1, and the measurement results of each comparative example are shown in Tables 2 and 3.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

EFFECTS OF THE INVENTION Vinyl chloride that can be produced by a calender rolling method by adding a hydrotalcite compound to a calcium-zinc metal compound stabilizer to improve heat resistance persistence without deteriorating initial coloring. Seats can be provided.

Claims (6)

[Claims] 1. A compound of calcium of 0.01 to 2 parts by weight, a compound of zinc of 0.01 to 2 parts by weight, a hydrotalcite compound of the formula (A) 0.1. A vinyl chloride sheet comprising a composition to which 01 to 5 parts by weight is added. [Mg _W · Al _X · (OH) _Y · (CO ₃ ) _Z ] mH ₂ O (A) However, W, X, Y and Z are positive numbers satisfying 2W + 3X = Y + 2Z, and W is 2 ≦. W ≦ 6, m is a positive number, and 2 ≦ m ≦ 4. 2. An epoxidized vegetable oil of 0.1 to 5 parts by weight, a calcium compound of 0.01 to 2 parts by weight, a zinc compound of 0.01 to 2 parts by weight, and a general formula ( A) A composition containing 0.01 to 5 parts by weight of a hydrotalcite compound, 0.01 to 2 parts by weight of an ester compound, and 0.01 to 1 part by weight of a β-diketone compound. Vinyl chloride sheet.
[Mg _W · Al _X · (OH) _Y · (CO ₃ ) _Z ] mH ₂ O (A) However, W, X, Y and Z are positive numbers satisfying 2W + 3X = Y + 2Z, and W is 2 ≦. W ≦ 6, m is a positive number, and 2 ≦ m ≦ 4. 3. The vinyl chloride sheet according to claim 2, wherein the ester compound is a mono- to tri-valent ester compound of glycerin and higher fatty acid. 4. The average degree of polymerization of the vinyl chloride resin is 500.
It is-1000, The vinyl chloride sheet of Claim 1, 2 or 3 characterized by the above-mentioned. 5. The vinyl chloride sheet according to claim 1, 2, 3 or 4, which has a soft temperature of 50 to 80 ° C. according to a soft temperature test of JIS K6734. 6. The vinyl chloride sheet has a thickness of 0.05 to 1
The vinyl chloride sheet according to claim 1, 2, 3, 4, or 5, wherein the vinyl chloride sheet has a size of mm.