JPS5829806B2 - timer information usage information - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to synthetic resin molded articles with improved surfaces.

More specifically, the present invention relates to a synthetic resin molded article in which a cured polymer coating having excellent abrasion resistance, impact resistance, and weather resistance is well adhered to the surface of a base resin.

Currently, many synthetic resin molded products are on the market, and while they have many excellent properties, they are manufactured from thermoplastic resins such as polymethacrylate resin, methyl methacrylate copolymer resin, polystyrene resin, polycarbonate resin, etc. Molded products are susceptible to wear.

As a result, the surface of the product is easily scratched during processing and transportation, which not only reduces the value of the product, but also tends to cause wiping and scratches while the product is being used, resulting in rough surface conditions.
It has the disadvantage that it loses its luster and becomes unusable, especially in molded products that require transparency.

Conventionally, these synthetic resin molded products have been manufactured using, for example, diethylene glycol bisallyl carbonate (1-1) (% Kosho 4.7-
1.31.4-6), diacrylate and dimethacrylate-1.
It is already known that by forming a cured polymer film of a compound such as No. 3546) on the surface, the wear resistance of the synthetic resin molded article is improved.

However, although molded products with the above-mentioned hardened coating on their surfaces have considerably better abrasion resistance than their base resins, they still do not have sufficient abrasion resistance and are prone to scratches. easy.

For example, steel, wool abrasion test (# between approx. 25 diameter
A hat made of 000 steel and wool is pressed so that a certain load is applied to the surface of the film.

1 at a speed of 40 revolutions per minute. When subjected to a method for observing the occurrence of scratches after OO rotation, if the load is small, almost no scratches will occur, but if the load exceeds 100 (Pi'), considerable scratches will occur.

On the other hand, a cross-linked polymer coating made by polymerizing and curing only a cross-linked polymerizable compound consisting of a multifunctional methacrylate or acrylate such as pentaerythritol trimethacrylate and pentaerythritol tetraacrylate described in U.S. Pat. No. 3,511,311 was used. Synthetic resin molded products have extremely excellent wear resistance, but the adhesion between the crosslinked coating and the base resin may be poor and may peel off, or the crosslinked coating may be brittle and the base material that is in close contact with it may peel off. It has the disadvantage that it deteriorates the mechanical properties of the resin and is prone to cracking due to impact.

In view of the above situation, the inventors of the present invention have conducted intensive research and found that a film-forming raw material consisting of a mixture of a trifunctional or higher functional crosslinking polymerizable compound and a bifunctional or lower functional polymerizable compound in a specific ratio is crosslinked and cured. The inventors have discovered that the above-mentioned drawbacks can be solved all at once by obtaining a synthetic resin molded product having a composite film tightly formed on its surface, and have completed the present invention.

The synthetic resin molded article according to the present invention is a molded article in which a cured film of a crosslinked polymer is in close contact with the surface of a base resin, and the cured film is made of acryloyloxy (CH2=
The molecule contains at least three unsaturated groups selected from CH-CO-C)-) and methacryloyloxy groups (CH2-C(CH3).C0-(,-), and the unsaturated groups are 20 an aliphatic hydrocarbon group having up to 1 carbon atoms (an ether bond may be included in the main chain of the aliphatic hydrocarbon group).

) (hereinafter referred to as component A or compound A) and a compound copolymerizable with the above (hereinafter referred to as component A or compound A) having one or two ethylenically unsaturated groups in the molecule (
A film formed by polymerizing and curing a polymerizable liquid material consisting of 80 to 20 parts by weight (hereinafter referred to as component B or compound B), and a pad made of OOO steel wool with a diameter of 25 mm is placed on the surface of the film. While pressing the pad so that a load of
It is characterized by having wear resistance to the extent that it does not substantially cause any scratches that are visible to the naked eye when rotated to zero.

The synthetic resin molded product having the crosslinked film on the surface of the present invention can be prepared by coating the surface of the synthetic resin molded product as a base material with a composition consisting of the above-mentioned components (A) and (B) by roller coating, barcoding, or spraying. Component (A) is applied by a coating method, an air knife coating method, a dipping method, etc., then rolled into a thin film, and crosslinked and cured in an inert gun or in a vacuum.
, a method for obtaining a molded article having a crosslinked and cured coating of a composition consisting of (B), and a sheet-like article having a smooth plane;
The above components (A), (
A composition consisting of B) is applied by the above coating method, and a mylar film, an aluminum thin plate, a titanium thin film,
It can be obtained by a method such as coating it with a coating material such as a glass plate or stainless steel plate, rolling it over it, crosslinking and curing it, and then peeling off the coating material to form a molded product having the above-mentioned coating on the surface. .

The base resin for the molded product according to the present invention includes methyl methacrylate resin, methyl methacrylate copolymer resin, polystyrene resin, polycarbonate resin, polyaryl diglycol carbonate resin, transparent ABS resin, and AS.
Examples include synthetic resin molded products such as resin.

Component (A) used for forming a crosslinked polymer film on the surface of a synthetic resin molded article in carrying out the present invention
is obtained by reacting a trihydric or higher polyhydric alcohol or its derivative with acrylic acid, methacrylic acid, or an oxide or ester of these acids, and is characterized by the presence of acryloyloxy in one molecule. It is a compound having three or more unsaturated groups selected from the group consisting of a methacrylic acid group and a meta-acIJ Dyloxy group.

In the compound (A), residues of polyhydric alcohol, that is, residues Q'3 connecting each acryloyloxy group or methacryloyloxy group, are generally aliphatic hydrocarbons or derivatives thereof containing an ether bond in the main chain. be.

Most preferred compounds for use in carrying out the present invention (
A) has 3 to 4 acryloyloxy groups in the molecule, and each acryloyloxy group is linked by a hydrocarbon having 20 or less carbon atoms, particularly preferably 10 or less without an ether bond. It is a compound that has been

As a compound similar to the compound (A), the residue connecting each acryloyloxy group or methacryloyloxy group is a cyclic hydrocarbon other than the above aliphatic hydrocarbon, an aliphatic compound containing an amide bond or a urethane bond, There are compounds composed of ・ and cyclic hydrocarbon groups, but since these all have poor reactivity during polymerization and curing reactions, the use of these compounds does not provide the excellent wear resistance that is the objective of the present invention. Not only is it not possible to obtain a molded product with a crosslinked film having a surface, but also the weather resistance and water resistance of the crosslinked film are significantly impaired due to the amide bonds and urethane bonds contained in the polyfunctional compound used, which is undesirable. .

Furthermore, acrylic-modified unsaturated polyesters having a similar structure to the component (A) obtained by modifying ordinary unsaturated polyesters with acrylic acid or methacrylic acid and their derivatives are also known. A coating obtained by using polyester in place of the compound (A) used in the present invention is not preferred because it is inferior in terms of abrasion resistance, water resistance, weather resistance, etc.

Furthermore, among compounds similar to the component (A), those in which the methacryloyloxy group and the aliphatic hydrocarbon group connected to the acryloyloxy group have 20 or more carbon atoms, the viscosity of the coating material containing the compound is extremely high. It gets expensive,
Otherwise, it becomes solid, making it difficult to form a synthetic resin molded article having a uniform and thin crosslinked coating on the surface, which is not preferable.

Preferred examples of the polyhydric alcohol used to form the compound in component (A) include trimethylolethane, trimethylolpropane, 1.2.6-hexanetriol, and glycerol.

Examples include pentaerythritol, diglycerol, dipentaerythritol, etc., and it is produced using only compounds having 3 to 4 acryloyloxy groups in one molecule obtained from these polyhydric alcohols and acrylic acid. The resulting crosslinked coating has particularly excellent scratch resistance, but is inferior in adhesion to the base resin and impact resistance, and cracks may occur when exposed outdoors.

In addition, compounds having 3 to 6 methacryloyloxy groups in one molecule, which can be obtained from the polyhydric alcohol and atacrylic acid, have slow polymerization, a lower final polymerization rate than the acrylate compound, and polymerization. Although it is somewhat brittle, compared to other polymerizable unsaturated groups, its crosslinking polymerizability and the properties of the resulting crosslinked cured product are also good, so it accounts for up to 50%, preferably up to 30%, of all unsaturated groups. It is recommended to use within the range of .

As a result of studies aimed at improving the weaknesses of the above-mentioned wear-resistant coatings, we found that a coating was obtained by curing a coating material consisting of 20 to 80 parts by weight of compound (A) and 80 to 20 parts by weight of compound (B). By doing so, we were able to achieve that purpose.

In carrying out the present invention, the above-mentioned component (A
) Examples of the compound include trimethylolpropane triacrylate, trimethylolethane triacrylate, and pentaerythritol tetraacrylate.

Synthetic resin molded products having a cross-linked polymer film made of these compounds on their surfaces not only have better abrasion resistance than those made with the dimethacrylate compounds, but also have better wear resistance than those made using the above-mentioned dimethacrylate compounds. The scratch resistance is so excellent that no scratches are observed with the naked eye even under a load of 3,000 P, and particularly preferred ones show no scratches at all under loads of 5,000 to 10,001 P.

In carrying out the present invention, it is necessary to eliminate the disadvantages of using component (A) alone as a component for forming a crosslinked polymer film on the surface of a synthetic resin molded product, that is, to eliminate the drawbacks of using component (A) alone as a component for forming a crosslinked polymer film on the surface of a synthetic resin molded product. Physical properties such as modification of impact resistance, strength, etc., improvement of weather resistance, improvement of adhesion between the crosslinked polymer coating and base resin, or adjustment of viscosity during coating prior to industrial polymerization and curing. For this purpose, it is necessary to use a compound having one or two ethylenically unsaturated groups in one molecule, that is, component (B), as a component for forming a crosslinked polymer film.

Compounds used as this component (B) include diacrylates of alkanediols having 2 to 6 carbon atoms, methacrylates, diacrylates of diethylene glycol, triethylene glycol, and tetraethylene glycol;
and dimethacrylate.

Among these compounds, diacrylates of alkanediols having 2 to 6 carbon atoms are preferred in view of the balance between abrasion resistance and other physical properties (e.g. impact resistance) of the crosslinked polymer coating, and their use The amount is usually determined by the amount of the component (
The amount is 80% by weight or less, more preferably 60% by weight or less based on the total amount of A) and (B).

In addition, commonly used compounds having a monoethylenically unsaturated group include acrylic acid, methacrylic acid, or alkyl (carbon number 1 to 4) esters thereof, acrylonitrile, methacrylonitrile, styrene, etc. The amount of these compounds used is the same as the component (A) above.
and 50% by weight in 100 parts by weight based on the total amount of (B)
The most preferred amount is 30% by weight or less.

The component (B), that is, a compound having one or two ethylenically unsaturated groups in one molecule, can be used alone or in combination of two or more, and can be used by mixing with the component (A). .

In carrying out the present invention, from the component (A), l-limethylolethane triacrylate, trimethylolpropane triacrylate, and pentaerythritol tetraacrylate, from the component (B), an alkanediol diacrylate having 2 to 6 carbon atoms, selected from acrylic acid and alkyl esters of acrylic acid having 1 to 4 carbon atoms, and the component (A) is 20 to 30 parts by weight, the component (B) is 80 to 20 parts by weight, and more preferably the component (A) ) is 4
A synthetic resin molded article having a crosslinked polymer film formed from a composition containing 0 to 80 parts by weight and 60 to 20 parts by weight of component (B) on its surface is recommended.

When component (A) in the composition is less than 20 parts by weight, 1
Although the impact resistance and weather resistance of the crosslinked polymer coating on the surface of the synthetic resin molded article and the adhesion between the base synthetic resin molded article and the crosslinked polymer coating are improved, the abrasion resistance is undesirable.

On the other hand, when the component (A) exceeds 95 parts by weight, the abrasion resistance of the crosslinked polymer coating is improved, but the impact resistance, weather resistance, and compatibility with the base synthetic resin molded product are improved. This is not preferable because it reduces adhesion.

In the above-mentioned steel wool abrasion test when carrying out the present invention, the composition that forms a crosslinked polymer coating having a scratch resistance to the extent that no scratches occur as judged by the naked eye at a load of 1001' is generally determined by the components ( It also depends on the number of ethylenically unsaturated groups in B).

In general, (1) in the case of a monoethylenically unsaturated compound, a mixture consisting of 70 parts by weight or more of the component (A) and 30 parts by weight or less of this component (B) is preferred, and (2) a diethylenically unsaturated compound In this case, a mixture consisting of 20 parts by weight or more of component (A) and 80 parts by weight or less of component (B) is preferred.

Furthermore, when carrying out the present invention, it is extremely valuable from a practical standpoint, and the steel-wool abrasion test has a load of 3000P.
However, if you want a coating with particularly high scratch resistance that does not cause scratches when judged with the naked eye, the above component (A) is 40 parts by weight or more, and the above component (B) is diethylenically unsaturated. Preferably, the mixture composition consists of 60 parts by weight or less of the compound.

In carrying out the present invention, since polymerization of the crosslinked polymer film-forming material consisting of the above-mentioned components (A) and (B) is inhibited by oxygen, in order to fully cure it, it must be cured under an inert gas atmosphere or under an inert gas atmosphere. It is necessary to carry out the polymerization in a state where oxygen is blocked, and in this case, unless the polymerization and curing is carried out as thoroughly as possible, the desired crosslinked polymer film with excellent wear resistance cannot be obtained.

Methods for polymerizing and curing the crosslinked polymer film-forming material include methods of adding a thermally decomposable polymerization initiator and heating, adding a photosensitizing compound and irradiating it with ultraviolet rays, and There are methods of irradiating with radiation and methods of irradiating with r-rays, and these methods can also be used in combination.

Examples of thermal decomposition type polymerization initiators include known radical polymerization initiators 1, for example, peroxides or azo compounds such as benzoyl peroxide, lauroyl peroxide, and azobisisophthyronitrile; and photosensitizers include: Selected from those whose main absorption wavelength is between 3000 and 4000A0,
Preferred compounds include carbonyl compounds, and among these, particularly preferred compounds include benzoin and its alkyl (1 to 4 carbon atoms) ethers.

These polymerization initiators can be used not only alone but also in combination of two or more, and the amount used is equal to the amount of the component (A).
The amount is usually within 5 parts by weight, preferably within 3 parts by weight, based on ioo parts by weight of the crosslinked polymer film forming raw material consisting of (B) and (B).

On the other hand, a crosslinked polymer film obtained by polymerization and curing using a polymerization initiator with low radical polymerization activity that requires the addition of 10 parts by weight or more under normal conditions may contain residual initiator or
This is not preferable because the plasticizing effect of the initiator residue significantly reduces wear resistance.

Further, when curing is performed using ionizing radiation, an electron beam obtained from an electron beam accelerator with an accelerating voltage of 20 to 500 KV is irradiated with a total absorbed dose in the range of 0.1 to 50 Mrad.

A particularly preferred polymerization curing method is a method using ultraviolet irradiation.

The thickness of the crosslinked polymer film formed on the surface of the synthetic resin molded product is usually 0.001 to lomyn, preferably 0.0
03-0.1, most preferably 0.005-0.0
It is necessary to make the film thickness 0.001
If it is less than mm, it is difficult to achieve the object of the present invention.

On the other hand, if the film thickness exceeds 1.0 mm, distortion may occur due to rapid volumetric shrinkage of the film during curing, or the adhesion between the film and the base synthetic resin molded product may deteriorate. , which is undesirable because optical distortion is likely to occur.

The surface of the crosslinked polymer coating on the synthetic resin molded article of the present invention is
It is extremely smooth and has excellent gloss, and the crosslinked polymer coating has excellent transparency.

Therefore, polymethyl methacrylate, which is characterized by transparency, methacrylate copolymer resin, polystyrene resin, polycarbonate resin,
It is most effective to use transparent ABS resin, AS resin, polyallylic glycol carbonate resin, etc.

Among these, polymethacrylate resins and methyl methacrylate copolymer resins are particularly preferred.

Example 1 A composition consisting of 100 parts by weight of the resin composition shown in Table 1 and 3 parts by weight of benzoin isopropyl ether was coated on a polymethyl methacrylate plate with a thickness of 0.05 mm.
I painted it to look like mrtt.

This coated product was placed directly under a high-pressure mercury lamp at 5 CIrL to create a nitrogen atmosphere, and then the coated film was cured by irradiating it with ultraviolet rays emitted from the high-pressure mercury lamp for 5 minutes.

Table 1 shows the results of measuring the coating film properties of this coated product.

The coating film performance was tested as follows.

Adhesion of the coating film to the base material: A width of 1 mm is applied to the coating surface of the coated product created by the construction method.
(7) Cut a diagonal pattern with a knife, adhere cellophane tape to this part, and then tear it off. If the diagonal pattern remained on the base material, ○, if part of it was peeled off, △, or completely peeled off. Objects are marked with an x.

Impact resistance of coating film: Measured by Dynstadt impact test according to B51330 method, and the strength was expressed in kg·cfrL/crA.

Weather resistance: Judgment was made by observing the state of the coating film when the coated product was treated with a Weather-O-meter (manufactured by Toyo Rika, carbon arc model WE-2) for 1100 hours.

Abrasion resistance: A rod with a #000 steel wool batt attached to the tip was placed on the surface of the crosslinked polymer coating, and the load shown in Table 1 was applied to the coating surface from the top of the rod. Observe the condition of the painted surface when the rod is rotated 100 times. Judgment was made based on the criterion that the film had completely lost its gloss and transparency.

In Table 1, compound (A) is trimethylolfuropane triacrylate, compound (B) is hexamethylene glycol diacrylate and methyl acrylate, 1=2
This shows the composition mixed in the following proportions.

In Table 1, experiment numbers 1, 2, 7, and 8 are comparative examples of the water injection invention, and experiment numbers 3 to 6 show the characteristics of the invention.

As is clear from the results in Table 1, the plastic products of the present invention have extremely good wear resistance, as well as weather resistance and
It can be seen that the adhesion of the coating film to the substrate and impact resistance are also good.

Example 2 A composition consisting of ioo parts by weight of a resin composition as shown in Table 2 and 2 parts by weight of benzoin butyl ether was coated on a polymethyl methacrylate plate having a thickness of 0.0 mm.
05 mm, and this coated board was used as Example 1.
A molded article with a crosslinked polymer film was made by irradiating it with ultraviolet rays in the same manner as above.

Table 2 shows the results of tests on the adhesion of the abrasion-resistant coating of the obtained product to the base material and weather resistance.

In Table 2, the symbols used for the resin composition items are as follows.

5E4A ; Pentaerythritol tetraacrylate TME3A ;) Lynchol ethane triacrylate * TMP3A ;) Lynchol propane triacrylate TMP 3MA; ) Lynchol propane trimethacrylate MA ; Methyl acrylate AA Niacrylic acid C6DA ; Hexamethylene diol diacrylate C4DA ; Butanediol Diacrylate 4E
DMA; tetraethylene glycol dimethacrylate MAA; methacrylic acid MEPH; It can be seen that the material also has excellent mechanical properties.

Example 3 A resin composition consisting of 50 parts of trimethylolpropane triacrylate, 50 parts of hexamethylene diol diacrylate, and 2 parts of benzoin isobutyl ether was prepared on a polymethyl methacrylate plate having a thickness of 5 mm as shown in Table 3. The product was coated to a film thickness as shown in Table 3 and irradiated with ultraviolet rays in the same manner as in Example 1 to produce a product having an abrasion resistant film.The properties of the product were tested and the results are shown in Table 3.

As is clear from the results in Table 3, the film thickness of the coating film is 0.1
If the size exceeds mm, shrinkage distortion occurs during crosslinking and curing of the coating film, resulting in decreased adhesion of the coating film to the substrate and optical distortion.

Also, if you try to apply the coating to a thickness of less than 0.001mm, you will not be able to form a uniform coating;
It was not possible to create a product with uniform properties.

Example 4 On a plate made of polymethyl methacrylate having a thickness of 51 nTL, a photosensitizer shown in Table 4 was added to ioo parts of a 1:1 mixture of trimethylolpropane triacrylate and hexamethylene diol diacrylate. The resin composition added in the proportions shown in the table was coated to a film thickness of 0.020 mm, and the coating film was crosslinked and cured by irradiating ultraviolet rays to the coating film in the same manner as in Example 1. The results of measuring membrane performance are shown in Table 4.

The abrasion resistance of the coating films in Table 4 was measured by a steel wool test at a load of 1.0 kg.

In addition, except for using a resin composition in which benzoin isopropyl ether was added in the ratio shown in Table 5 to 100 parts of a 1:1 mixture of trimethylolpropane triacrylate and hexamethylene diol diacrylate as a resin composition. A polymethyl methacrylate plate having a cured film was prepared in exactly the same manner as the method, and its performance was tested. Table 5 shows the results.

A resin composition consisting of 70 parts of trimethylolpropane triacrylate I, 20 parts of hexamethylene diol diacrylate, and 10 parts of methyl acrylate was applied to a plastic plate with a thickness of 5 mm as shown in Table 6 to give a film thickness of 0.020 mm. After coating and pasting the polyester film, the acceleration voltage was 300KV, the current density was 2077LA, and the dose rate was 3M.
Table 6 shows the results of testing the properties of plastic products obtained by irradiating them with electron beams at an absorbed dose of 8 Mrad under the conditions of rad/sec.

Claims (1)

[Scope of Claims] 1. A molded article with excellent abrasion resistance in which a cured film of a polymer having crosslinking bonds adheres to the surface of a base resin, in which the cured film has an acryloyloxy group (CH2=CH- C
O-0-) and methacryloyloxy group (CH2-C
an aliphatic hydrocarbon group (the aliphatic hydrocarbon (The main chain of the hydrogen group may contain an ether bond.) 20 to 80 parts by weight of a compound linked to a hydrogen group and a compound copolymerizable with the above compound having one or two ethylenically unsaturated groups in the molecule. A film formed by polymerizing and curing a polymerizable liquid material consisting of 80 to 20 parts by weight of a compound, and while pressing a pad made of #000 steel wool with a diameter of 25 mm to the surface of the film so as to apply a load of 100 OP. A synthetic resin molded product characterized by having such abrasion resistance that substantially no visible damage occurs when the pad is rotated 100 times at a rate of 40 revolutions per minute.