JPH044338B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vinyl chloride-based agricultural vinyl sheet that has extremely improved blocking resistance without impairing transparency, weather resistance, and fish eye resistance (hereinafter referred to as FE). More specifically, a specific partially crosslinked vinyl chloride resin alone containing a gel content of 0.02 to 1.0% (wt%, the same applies hereinafter), or a specific partially crosslinked vinyl chloride resin containing preferably a gel content of 1.0 to 50% A mixed resin consisting of a polyvinyl chloride resin for adjusting the gel content, and the ratio of the gel content to the total resin amount is 0.02 to 1.0.
The present invention relates to a vinyl chloride-based agricultural vinyl sheet that is made of a resin with an extremely high blocking resistance and has extremely improved blocking resistance without impairing transparency, weather resistance, and FE resistance. Vinyl chloride resins have excellent properties and are used in a wide range of fields. Among them, it is used as various transparent films and sheets in various fields such as packaging, stationery, agriculture, and miscellaneous goods. When manufacturing hard, semi-hard, or soft transparent sheets or films, they are usually stored in a rolled state or in a stacked state in a sheet state. However, if the film or sheet is to be peeled off from such a roll or sheet in a later process, the films or sheets will block each other and cannot be easily peeled off. Therefore, there are problems such as a significant decrease in workability. Various attempts have been made in this industry to solve this problem, but so far no simple and effective method has been found, and each company has tried their best to solve the problem. The current situation is that For example, there are methods to prevent blocking by sprinkling organic substances such as starch all over the surface of the film or sheet, and methods to prevent blocking by kneading fine powder of inorganic substances such as calcium carbonate. It's a method. However, in these methods, the process becomes complicated, workability deteriorates, and in order to obtain an effective anti-blocking effect, it is necessary to use a large amount of the powder, and as a result, the film or sheet deteriorates. Transparency will be impaired and the above method will only give unsatisfactory results.
The same applies to molded products other than films and sheets; if they are stored in piles, blocking occurs, and when they are removed, the appearance of the removed surface is impaired. Further, the use of crosslinked vinyl chloride resins has recently attracted attention, and compositions containing various partially crosslinked vinyl chloride resins have been studied. For example, a proposal was made to obtain a partially crosslinked vinyl chloride resin using a crosslinking agent such as diallyl phthalate, diallyl maleate, polyethylene glycol diacrylate, or polyethylene dimethacrylate, and to utilize a composition using this -80354, Japanese Unexamined Patent Publication No. 56-5843, etc.). However, molded products obtained from compositions using conventional partially crosslinked vinyl chloride resins have extremely poor weather resistance and cannot be used for applications such as agricultural vinyl sheets. The present inventors have conducted extensive research with the aim of obtaining a vinyl chloride-based agricultural vinyl sheet that has improved blocking resistance without impairing transparency, weather resistance, and FE resistance. A vinyl chloride resin with a gel content of 0.02 to 1.0% in the total resin component, wherein the gel content is composed of vinyl chloride or a monomer mixture (A) mainly composed of vinyl chloride and a bisphenol-modified resin. It has been discovered that an agricultural vinyl sheet comprising a resin contained as a partially crosslinked vinyl chloride resin obtained by copolymerizing a monomer mixture (B) comprising an acrylate or a bisphenol-modified dimethacrylate can achieve the above object, We have now completed the present invention. In this specification, the gel fraction (gel fraction) is a value calculated by extracting with tetrahydrofuran for 22 hours using a Soxhlet extractor and calculating the dry weight of the extraction residue remaining on a 350 mesh filter. It is. In the present invention, a monomer mixture (A) consisting of vinyl chloride or a monomer mixture mainly composed of vinyl chloride and a bisphenol-modified diacrylate or a bisphenol-modified dimethacrylate (B) is used.
The gel fraction obtained by copolymerizing is 0.02 to 1.0%.
A partially crosslinked vinyl chloride resin or a partially crosslinked vinyl chloride resin whose gel fraction is preferably 1.0 to 50% is blended with a vinyl chloride resin for gel content adjustment described below to reduce the gel content to the total resin content. Rate is
The amount adjusted to 0.02-1.0% is used. When partially crosslinked vinyl chloride resin is used alone, if the gel fraction is 1.0% or more, the F resistance will be reduced.
E. It is undesirable because it deteriorates the quality and transparency.
Furthermore, if it is less than 0.02%, the anti-blocking effect will be reduced, which is not preferable. In addition, when used in combination with vinyl chloride resin to adjust the gel fraction, the gel fraction of the partially crosslinked vinyl chloride resin will be 50%.
If it exceeds, for example, even if the gel fraction relative to the total resin content is subsequently adjusted to 1.0% or less, the FE resistance or transparency tends to deteriorate and become undesirable. Furthermore, if the gel fraction is less than 0.02% based on the total amount of resin, the anti-blocking effect will be reduced, which is not preferable. Incidentally, the production of the partially crosslinked vinyl chloride resin used in the present invention is disclosed in JP-A-57-195711 and other publications. The crosslinking agent used in the present invention is bisphenol-modified diacrylate or bisphenol-modified dimethacrylate, and among them, the general formula (): General formula (): or general formula (): (In the formula, R ₁ is H atom or -CH ₃ group, R ₂ is H
Atom or alkyl group having 1 to 4 carbon atoms, R ₃ , R ₄
is an H atom, -CH ₃ group, -CH ₂ CH ₃ group, -
Atoms or groups selected from CH ₂ CH ₂ COOH groups,
i and j are integers from 1 to 5, m and n are integers from 1 to 10,
A compound represented by the following formula is preferably used: 1 is 0 or an integer of 1 to 20, and X is a Br atom, a Cl atom, or a hydrogen atom. In the present invention, the gel fraction is preferably 1.0 to 50.
As the vinyl chloride resin for gel content adjustment, which is used to adjust the gel fraction when using a partially crosslinked vinyl chloride resin that is Examples include vinyl chloride resins that are obtained by polymerization and do not contain gel components. Specific examples of such vinyl chloride resins include polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, vinyl chloride and acrylic acid, or Copolymers with esters, copolymers with vinyl chloride and maleic acid or its esters,
Examples include copolymers of vinyl chloride and fumaric acid or its esters. To obtain the agricultural vinyl sheet of the present invention, the partially crosslinked vinyl chloride resin or the mixed resin of the partially crosslinked vinyl chloride resin and the vinyl chloride resin are added with, for example, a heat stabilizer, an ultraviolet absorber, a lubricant, an oxidizing agent, etc. It is molded by adding inhibitors, processing aids, pigments, fillers, plasticizers, or other modifiers as necessary. The molding process may be carried out by a known method for molding a normal vinyl chloride resin. In the present invention, since the purpose is to obtain an agricultural vinyl sheet with good transparency, weather resistance, FE resistance, and blocking resistance, lead-based stabilizers and fillers, which are undesirable for improving transparency, are used. , pigments, modifiers or processing aids are preferably used in small amounts. Therefore, particularly preferred thermal stabilizers include Ca-Ba stabilizers, Ca-Zn stabilizers,
Examples include Sn-based stabilizers and Ba-Zn-based stabilizers. Particularly preferred lubricants include stearic acid, polyethylene wax, and montan acid wax. Furthermore, plasticizers are used for the purpose of softening or improving processability, and conventionally known plasticizers can be used as needed. For example, phthalate plasticizers,
These include adipate ester plasticizers, sebacate ester plasticizers, phosphate ester plasticizers, trimellitate ester plasticizers, and polyester plasticizers. Moreover, you may use 2 or more types of them together. Hereinafter, the agricultural vinyl sheet of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. Reference Example 1 (Manufacture of partially crosslinked vinyl chloride resin (1)) 200 parts of ion-exchanged water (parts by weight, the same applies hereinafter) and partially saponified polyvinyl acetate in a 50 stainless steel polymerization machine
0.2 parts, di-2-ethylhexyl peroxydicarbonate 0.03 parts and tetraethylene glycol diacrylate After charging 2.0 parts and degassing, add 100 parts of vinyl chloride monomer.
After polymerizing at 55°C for 15 hours and dehydrating and drying the slurry, a white powder was obtained. The resulting resin had a gel fraction of 28% and a soluble polymerization degree of 1020. Reference Example 2 (Production of partially crosslinked vinyl chloride resin (2)) Tetraethylene glycol diacrylate 2.0
A white powder was obtained in exactly the same manner as in Reference Example 1 except that the part was changed to 0.3 part. The gel fraction of the resin is 0.80
%, and the degree of soluble polymerization was 1010. Reference Example 3 (Production of partially crosslinked vinyl chloride resin (3)) Tetraethylene glycol diacrylate 0.3
Part of polyoxyethylated bisphenol A diacrylate A white powder was obtained in exactly the same manner as in Reference Example 2 except that the amount was changed to 0.1 part. The resin had a gel fraction of 0.01% and a soluble polymerization degree of 1090. Reference Example 4 (Production of partially crosslinked vinyl chloride resin (4)) Reference Example 3 except that 0.1 part of polyoxyethylene bisphenol A diacrylate was changed to 0.3 part.
A white powder was obtained in exactly the same manner as above. The gel fraction of the resin was 0.81%, and the degree of soluble polymerization was 1080. Reference Example 5 (Manufacture of partially crosslinked vinyl chloride resin (5)) Reference Example 4 except that 0.3 part of polyoxyethylene bisphenol A diacrylate was changed to 1.0 part.
A white powder was obtained in exactly the same manner as above. The resin had a gel fraction of 18.0% and a soluble polymerization degree of 1080. Examples 1 to 4 and Comparative Examples 1 to 6 Ca-Zn stabilizers, stearic acid, dioctyl phthalate (DOP), and epoxidized soybean oil were added to the resin components shown in Table 1.
Blend the amount shown in the table, put it into an 8-inch roll controlled at 160℃, knead for 8 minutes, and mix 0.2
A film with a thickness of mm was produced. In Table 1, Kanevinyl S-1001 (trade name) is a polyvinyl chloride with a degree of polymerization of 1050 manufactured by Kanebuchi Chemical Industry Co., Ltd.
1008 (trade name) is a vinyl chloride-vinyl acetate copolymer with a polymerization degree of 800 manufactured by Kanekabuchi Chemical Industry Co., Ltd. Various physical properties of the 10 films thus obtained were measured and evaluated as follows. The results are shown in Table 1. In Table 1, the gel fraction in all resin components is a value calculated from the gel fraction of the partially crosslinked vinyl chloride resin used. (Blocking resistance) Two 10cm x 10cm, 0.2mm thick films are stacked together.
After applying a load of 50 kg/cm ² and leaving it at room temperature for 24 hours, the ease of peeling of the two films was evaluated as extremely easy to peel (◎), easy to peel (〇), slightly difficult to peel (△), and difficult to peel. Evaluation was made on a four-level scale (×). (Transparency) 30 sheets of 10 cm x 10 cm, 0.2 mm thick films were stacked together and heat pressed at 170°C x 10 minutes x 50 kg/cm ² to produce a 5 mm thick plate. The total light transmittance (%) of the plate was measured. (FE resistance) Prepare 5 films of 10cm x 10cm and 0.2mm thick, measure the number of particles present in each film, calculate the average value of the 5 films, and calculate the number of particles/10cm x 10cm.
Displayed in units of . (Weather Resistance) A 10 cm x 10 cm, 0.2 mm thick film was allowed to deteriorate for 200 hours using a Sunshine Weather-Ometer, and then the elongation rate (%) was measured. In addition,
The elongation rate was measured in accordance with JIS K6724.
The deterioration conditions were 63°C and raining every 2 hours for 18 minutes. In addition, the front and back sides of the test samples were changed every 20 hours.

【table】

[Table] From the results in Table 1, Comparative Examples 1 and 2, which do not contain partially crosslinked vinyl chloride resins, have no blocking resistance at all, and Comparative Examples 3 and 5, which do not contain partially crosslinked vinyl chloride resins, have no blocking resistance. When the resins (1) and (2) are used, the weather resistance is greatly reduced, and even if the same type of partially crosslinked vinyl chloride resin used in the present invention is used as in Comparative Example 4, the gel content is low. When the ratio is set to 0.01%, the anti-blocking property is not good, and when the blending amount of the partially crosslinked vinyl chloride resin (5) is increased and the gel fraction in the pre-resin content is set to 3.0% as in Comparative Example 6. Transparency is reduced;
It can be seen that both are undesirable. On the other hand, Examples 1, 2, 3, and 4 have transparency and FE resistance equivalent to straight PVC alone, and also exhibit properties equivalent to or better than straight PVC in terms of weather resistance and blocking resistance. I understand that.

Claims (1)

[Claims] 1. The ratio of gel content in all resin components is 0.02.
~1.0% by weight of a vinyl chloride resin,
Partially crosslinked vinyl chloride obtained by copolymerizing vinyl chloride or a monomer mixture (A) whose gel content is mainly composed of vinyl chloride and a monomer mixture (B) consisting of a bisphenol-modified diacrylate or a bisphenol-modified dimethacrylate. Agricultural vinyl sheet made of resin contained as a system resin. 2 Bisphenol-modified diacrylate or bisphenol-modified dimethacrylate has the general formula (): (In the formula, R ₁ is H atom or -CH ₃ group, R ₂ is H
Atom or alkyl group having 1 to 4 carbon atoms, R ₃ , R ₄
is an H atom, -CH ₃ group, -CH ₂ CH ₃ group, -
Atoms or groups selected from CH ₂ CH ₂ COOH groups,
The agricultural vinyl sheet according to claim 1, wherein m and n are integers of 1 to 10, and X is a Br atom, a Cl atom, or a H atom. 3 Bisphenol-modified diacrylate or bisphenol-modified dimethacrylate has the general formula (): (In the formula, R ₁ , R ₃ , R ₄ , and X are the same as above, and l is 0 or an integer from 1 to 20.) Agricultural vinyl sheet according to claim 1 . 4 Bisphenol-modified diacrylate or bisphenol-modified dimethacrylate has the general formula (): (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , l, and X are the same as above, and i and j are integers of 1 to 5.) Agricultural vinyl sheet. 5. The agricultural vinyl sheet according to claim 1, wherein the vinyl chloride resin having a gel content of 0.02 to 1.0% by weight in the total resin component is the partially crosslinked vinyl chloride resin. 6. The vinyl chloride resin having a gel content of 0.02 to 1.0% by weight in the total resin component is a mixed resin of the partially crosslinked vinyl chloride resin and the vinyl chloride resin. Agricultural vinyl sheet.