RU2147999C1 - Method of manufacture of polymer laminated materials - Google Patents

Abstract

FIELD: technology of manufacture of polymer laminated materials used for making profiled articles, including large-sized articles at deep drawing (baths, furniture, domestic devices, etc.). SUBSTANCE: method consists in pouring filling composition into mold made from silicate glass and hard thermoplastic, hardening this composition and withdrawing the material. Filling composition includes 2-30-% syrup of vinyl (c) polymer in methyl methacrylate and polymerization initiators. Hardening is effected at two stages. Used as initiator at first stage is mixture of photoinitiators: 0.1 to 0.3-% of 2-hydroxy-1.2-diphenyl ethanon and 0.01 to 0.1-% bis [2.4.6.-trimetnylbenzoyl] - phenylphosphinoxyde; used as initiator at second stage is 0.3 to 0.7% initiator at critical decomposition temperature of 60 to 80 C and 0.2 to 0/5 % initiator at critical decomposition temperature of 90 to 120 C. Hardening at first stage is effected at temperature of 15 to 30 C for 3 to 4 h. Hardening at second stage is first effected at temperature of 70 to 80 C for 1 to 6 h and then at temperature of 115 to 120 C for 1 to 2 h. Total duration of process is 5 to 11 h including 3 to 4 h at room temperature. EFFECT: intensification of process; reduced power requirements; flaw-free materials. 3 cl, 1 tbl

Description

 The present invention relates to the chemistry of polymers, and in particular to a method for manufacturing polymer layered materials intended for the manufacture of shaped products, including large-sized ones with a deep degree of drawing (bathtubs, furniture, housings, household appliances, etc.).

 Polymers of this purpose should be easily molded, have high structural strength during operation, attractive appearance. These requirements are most satisfied with laminated materials [1].

 The technology of manufacturing layered materials should be quite cheap, that is, have high performance at low energy consumption.

 A method for producing multilayer films and sheets from two or more incompatible polymers by coextrusion through a flat slot head is patented. In this case, films and sheets based on polystyrene are obtained that are duplicated on one side with a layer of ABS plastic [2] or laminates consisting of a base layer based on polystyrene, an outer layer of ABS plastic and an intermediate layer of another ABS material [3].

 The disadvantages of the obtained materials are: low weather resistance; lack of decorativeness (traces of extrusion remain on the surface); limited color gamut of the material (switching to another color is an expensive operation).

 It is known to obtain a decorative laminated sheet material by continuously feeding a film-bearing film and a liquid polymerizable resin (acrylic resin, a mixture of methyl methacrylate and polymethyl methacrylate) between two continuous tapes of a molding machine [4] or by layering a polyacrylic film on the molding surface of one or both parts of the mold, pouring it into the form of acrylic monomer and its polymerization [5]. However, the above methods are applicable only if the film material is compatible with the material of the liquid polymerizable resin, in addition, the strength properties of the obtained material are insufficient for large-sized products.

A polymer composition is patented for sanitary products with improved water, chemo and weather resistance, containing 0.1 - 49% elastomer (a copolymer of ethylene and vinyl acetate, butadiene and styrene or acrylates, styrene and acrylates and polybutadiene) with T _glass. ≤ 0 ^o or grafted copolymer based on this elastomer.

According to an example, the process for obtaining products consists of the following main stages:
1) synthesis of elastomer at 65 - 80 ^o C;
2) grafting onto its surface a copolymer at 75 - 85 ^o C;
3) mixing the obtained grafted copolymer with a methacrylate resin, a pigment and a heat stabilizer;
4) obtaining a sheet by extrusion;
5) pressing the product at 190 ^o C;
6) layering on the outer surface of the fiberglass bath [6].

 The patented composition is complex in composition and requires significant energy and labor costs. So, only to obtain a grafted copolymer (stage 1-2) requires 13 components and 42 hours. The process of obtaining the product from the composition (stage 3-6) is no less complicated.

 As a prototype taken a method of manufacturing a multilayer molded layered materials. The rigid polymer composite sheet includes a layer of transparent or colored acrylic polymer material cast on the surface of a substrate of another polymer. Products such as bathtubs, small boats, parts of automobile hulls, etc., are made from a sheet by vacuum thermoforming. The method consists in preparing an acrylic composition containing a free radical type polymerization initiator, casting this composition onto the surface of a thermoplastic polymer, and multistage curing the composition.

According to the example of the invention, 100 g of syrup, including 90% methyl methacrylate and 10% polymethyl methacrylate, are mixed with 0.5 g of di (sec-butyl) peroxydicarbonate (critical decomposition temperature 35 ^° C.), 0.2 g of dodecyl mercaptan and 0, 5 g of benzoyl peroxide (critical decomposition temperature of 70 ^o C).

After deaeration, this mixture is filled into a mold having a base of a glass plate and the top of rigid polyvinyl chloride. Both plates are separated along the perimeter by an elastic gasket. The mold is placed in an oven, where it is first kept at a temperature of 50 - 55 ^° C for 16 hours, then at 80 ^° C for 2 hours and at 105 ^° C for 2 hours (total duration - 20 hours).

 After cooling, an acrylic-coated polyvinyl chloride composite sheet is obtained. This sheet is molded and processed without delamination.

 In the case of using ABS plastic when composing forms, its surface is additionally protected from the action of methyl methacrylate by extruding a layer of polyvinyl chloride [7 - prototype].

The disadvantages of the method are the duration of the process (total duration of 20 hours) and its energy intensity (in the first stage, the temperature of 50 - 55 ^o C can withstand 16 hours).

 In addition, when using ABS plastic, there is a complication of technology.

 The invention solves the problem: the intensification of the manufacturing process of layered materials, reducing its energy consumption while maintaining the quality of the material and products after molding.

The specified technical result is achieved by the fact that in the method of manufacturing polymer layered materials, which consists in pouring into a mold made of silicate glass and a rigid thermoplastic, and curing the casting composition, including 2-30% syrup of vinyl (co) polymer in methyl methacrylate and the initiator polymerization, followed by extraction of the finished material, while curing is carried out in two stages, 0.3 to 0.7% of the initiator with a critical decomposition temperature of 60 - 80 ^o C and, in unlike the known, an additional 0.2 - 0.5% initiator is introduced with a critical decomposition temperature of 90 - 120 ^o C, and in the first stage of curing a mixture of photoinitiators is used: 0.1 - 0.3% 2-hydroxy-1,2- diphenylethanone and 0.01-0.1% bis [2,4,6-trimethylbenzoyl] phenylphosphine oxide.

Curing in the first stage is carried out at a temperature of 15 - 30 ^o C for 3-4 hours.

Curing in the second stage is carried out first at a temperature of 70 - 80 ^o C for 1-6 hours, and then at a temperature of 115 - 120 ^o C for 1-2 hours

 These distinctive features allow us to intensify the manufacturing process of layered materials, reduce its energy intensity and at the same time maintain the quality of the layered material and products from it after molding.

 The use in the first stage of curing only one of the claimed photoinitiators, or a mixture of one of them with another known photoinitiator, or curing in the second stage without an additional thermal initiator leads to the appearance of various defects in the layered material or in the products after molding (see table, examples for comparisons).

 The following are examples illustrating the invention.

 Examples 1-3.

 The vinyl (co) polymer is dissolved in methyl methacrylate, photo and thermal initiators are added to it, as well as a dye or pigment (in examples 1 and 2). The mixture is evacuated and poured into a mold of rigid thermoplastic and two sheets of silicate glass. When arranging the molds, the thermoplastic is laid on silicate glass and covered with another silicate glass, after laying an elastic gasket.

 The mold is placed under LUF-80 lamps and held until hard polymethyl methacrylate is formed. Then the form is transferred to the cabinet and thermosetting is carried out. After cooling, the thermoplastic sheet duplicated with polymethyl methacrylate is removed from the mold. The resulting material is suitable for sawing and molding without defects.

 The composition of the casting composition, as well as modes of curing are shown in the table.

From the above examples and the table it can be seen that the proposed method for the manufacture of polymer layered materials allows to intensify the process (total duration of 5 to 11 hours versus 20 hours for the prototype), to reduce energy consumption (the first stage of curing at room temperature for 3-4 hours against 50 - 60 ^o C for 16 hours according to the prototype) while maintaining the quality of the layered material (defects in the material after curing and products after molding are absent).

 The specified technical result is absent outside the claimed range of concentrations of photo and thermal initiators.

 References.

 1. Construction newspaper, 1998, N 10, p. 8.

 2. US patent N 4100237, MKI B 29 F 3/10, publ. 11.11.78.

 3. US patent N 4221836, MKI B 32 B 25/08, publ. 9.09.80.

 4. US patent N 4254074, MKI B 29 D 7/14, publ. 03.03.81.

 5. US patent N 4415509, MKI B 29 D 7/14, publ. 11/15/83.

 6. Japanese application N 61-252263, MKI C 08 L 33/12, C 08 L 23/08, publ. 11/10/86.

 7. US patent N 4892700, MKI B 29 C 47/06, B 29 C 51/02, B 29 C 51/10, publ. 1/9/90. (prototype).

Claims (3)

1. A method of manufacturing a polymer laminated material, which consists in pouring into a mold made of silicate glass and a rigid thermoplastic, and curing the casting composition, including 2-30% syrup of vinyl (co) polymer in methyl methacrylate and a polymerization initiator, followed by extraction of the finished material, wherein the curing is carried out in two steps as an initiator and a second stage using 0.3 - 0.7% of the initiator having a critical temperature decay 60 - 80 ^o C, characterized in that the second stage cure complement itelno using 0.2 - 0.5% of the initiator having a critical temperature decay 90 - 120 ^o C, and at the first curing step, a mixture of photoinitiators: 0.1 - 0.3% 2-hydroxy-1,2-difeniletanona and 0 01 - 0.1% bis [2,4,6-trimethylbenzoyl] phenylphosphine oxide. 2. A method of manufacturing a polymer laminate according to claim 1, characterized in that the curing in the first stage is carried out at a temperature of 15-30 ^o C for 3 to 4 hours 3. A method of manufacturing a polymer laminate according to claims 1 and 2, characterized in that the curing in the second stage is carried out first at a temperature of 70 - 80 ^o C for 1 to 6 hours, and then at a temperature of 115 - 120 ^o C for 1 - 2 hours

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